Podcast Host: Dr. Andrew Huberman (Stanford Associate Professor - brain development, brain plasticity, and neural regeneration and repair fields).

Lab Website

YouTube

Podcast Guest: Jeffrey Goldberg (Professor and Chair of the Department of Ophthalmology at the Byers Eye Institute, Stanford University )

Academic Profile

Lab Website

Key takeaways

Early intervention and ocular training can restore eye-brain connections, improving visual capacity in children (Segment 03).
Outdoor activities in children are associated with a lower risk of developing myopia (Segment 04).
Using reading glasses can lead to over-accommodation in young adults during visual tasks (Segment 07).
Near-Far exercise may not significantly improve presbyopia, while altered eye movements indicate concussions (Segment 11).
Contact lenses offer advantages for vision correction, but aging and proper maintenance are important considerations (Segment 14).
Proper eyelid hygiene, anti-inflammatory eye drops, and PRP show potential for treating dry eye (Segment 19).
Smoking, vaping, and cannabis use can negatively impact vision and ocular health (Segment 25).

(01): 00:00:00 Dr. Jeffrey Goldberg

The lab of Dr. Jeffrey Goldberg focuses on treating eye illnesses like glaucoma and retinal pigmentosa. Dr. Goldberg also creates treatments for blindness. Additionally, he has an extensive understanding of anything vision-related. In his line of expertise, he primarily treats patients with cataracts, glaucoma, other retinal and optic nerve conditions, or both. To treat visual damage, his team is creating cutting-edge nanotherapeutic and stem cell therapies. His work on neuroprotection and regeneration focuses on the retinal ganglion cells and the optic nerve, which are essential in glaucoma and other visual neuropathies. In this podcast, Dr. Goldberg discusses a variety of methods for preserving and enhancing eyesight throughout life, from behavioral strategies to specialized eye exercises that have been shown to enhance vision [1].

References

1. Jeffrey Goldberg, MD, Ph.D. Available from: https://profiles.stanford.edu/jeffrey-goldberg

(02): 00:06:29 Childhood & Eye Exams

Conducting a thorough ocular examination for newborns is of utmost importance, and it is recommended that they undergo such an evaluation. The red reflex is an optical phenomenon that results from the reflection of light by the retina towards an aperture designed explicitly for observation. The transmission of light through the aperture of the eye leads to the appearance of a luminous sensation that displays a tint of reddish-orange color. This phenomenon is a commonly observed occurrence in photographs captured through the utilization of flash photography. The employment of red reflex testing is a crucial technique for detecting anomalies in the visual axis or retina, often characterized by opacities. The efficacy of the red reflex can be reduced in both anterior and posterior regions due to the translucency of anatomical components such as the tear film, cornea, aqueous humor, lens, vitreous gel, and retina. The detection of anomalies in the red reflex among pediatric patients can function as an initial indication of ocular irregularities that may lead to amblyopia, a vision-threatening condition, or more severe pathologies such as retinoblastoma. Similarly, the red reflex can assist in the diagnosis of conditions that lead to impaired vision in adult populations. During the process of conducting an ocular examination, it is essential to carry out a thorough assessment of the red reflex. The evaluation entails the examination of the presence or absence of the red reflex, along with an assessment of its chromaticity, luminance, and notably, intraocular symmetry [2]. An additional ocular ailment. Retinoblastoma is a rare type of ocular neoplasm. Newborns lack the red-eye reflex, which facilitates their prompt screening following delivery. Retinoblastoma exhibits a higher incidence rate in the pediatric population, particularly in individuals who are younger than 5 years old. As per documented accounts, England records an estimated 36 instances of retinoblastoma on a yearly basis. Bilateral retinoblastoma is typically diagnosed during the first year of an infant's life. The diagnosis of unilateral ocular impairment is often delayed in individuals, with symptoms typically manifesting during the period of two to three years of age [3].

Figure 01. Optimizing CARs for ocular delivery [4].

References

2. EXAMINATION OF THE RED REFLEX IN PEDIATRIC AND ADULT PATIENTS. Available from: https://morancore.utah.edu/basic-ophthalmology-review/examination-of-the-red-reflex-in-pediatric-and-adult-patients/.

3. What is retinoblastoma? ; Available from: https://www.cancerresearchuk.org/about-cancer/childrens-cancer/eye-cancer-retinoblastoma/about.

4. Nellan, A. and T.J. Fry, Optimizing CARs for ocular delivery. Nature Cancer, 2020. 1(10): p. 939-940.

(03): 00:11:36 Eye Misalignment & Recovery

The timely correction of ocular misalignment is of paramount importance owing to the possibility of the brain neglecting the input from one of the eyes, leading to inadequate development of neural connections. If left unattended during the developmental stage of childhood, this matter can result in an irreversible decline in visual capacity beyond a specific threshold. It has been observed that young children exhibit the potential to restore the connection between the eye and brain that may have been compromised during the early phases of their growth and development, leading to visual impairment. During the period of adolescence, it is possible to participate in ocular training methods that may enhance the potency of the less dominant eye and the repositioning of ocular muscles, thus encouraging synchronized operation and prolonged visual concentration. Variability in critical period plasticity has been observed among different brain regions that are implicated in visual processing and eye connectivity. The impact of "molecular brakes" on the connections within the fear system can be deduced by examining their effect on the development of the visual system, which is frequently employed as a model for critical period plasticity. Comparable molecular mechanisms are involved in the development of two distinct brain regions. The discovery of these mechanisms during the visual critical period offers new insights and a theoretical framework for exploring innovative therapeutic interventions for aberrant fear responses in post-traumatic stress disorder, as recommended by therapeutic modalities. The investigation of the nogo receptor signaling pathway, which is associated with myelin and the Lynx family, along with their epigenetic modulators, offers a promising approach to studying the development of the fear system. It is possible to identify potential therapeutic targets. The present assessment exhibits a limited comprehension of the interplay between inhibitory mechanisms, encompassing age-related phenomena such as hippocampal neurogenesis. A comprehensive understanding of the molecular inhibitory pathways is crucial for future therapeutic investigations aimed at improving the modulation of essential period processes. The investigation of the mechanism accountable for the re-closure that follows the therapeutic reopening of the critical period holds significant importance in the domain of academic research [5].

Figure 02. Eye Misalignment & Recovery [6].

References

5. Nabel, E. and H. Morishita, Regulating Critical Period Plasticity: Insight from the Visual System to Fear Circuitry for Therapeutic Interventions. 2013. 4.

6. STRABISMUS. Available from: https://envisioneye.com.au/eye-conditions/childrens-eye-conditions/strabismus/.

(04): 00:20:38 Myopia (Near-Sightedness), Children & Sunlight

Myopia is a refractive error that can be caused by either an elongation of the eyeball or excessive curvature of the cornea. The previously mentioned phenomenon results in the relocation of the light's focal point anterior to the retina. The optical mechanism of the human eye is insufficient in attaining precise focus, leading to the perception of distant objects as indistinct or ambiguous. Myopia is a prevalent condition that impacts around 30% of individuals residing in the United States. The etiology of myopia remains incompletely comprehended. Nonetheless, a substantial amount of evidence indicates that a considerable fraction of individuals acquires myopia or a predisposition to its development through inheritance. Offspring have an elevated probability of developing myopia when one or both biological parents exhibit myopia. While a genetic predisposition to myopia is present, an individual's ocular habits have the potential to influence the onset of the condition. Studies have indicated that individuals who undertake activities that require sustained visual focus over prolonged durations, such as reading, operating a computer, and engaging in video games, are more susceptible to developing myopia. There exists a correlation between the prolonged utilization of intelligent devices, specifically smartphones, and an increased likelihood of the onset of myopia. The correlation in question has been recorded to result in a rise of approximately 30%. Furthermore, when utilized in conjunction with extended periods of computer operation, this risk escalates to approximately 80%. Research suggests that children who participate in outdoor activities are less likely to develop myopia in comparison to those who spend the majority of their time indoors. Engaging in outdoor exercise is believed to contribute to the promotion of healthier eyes [7].

Figure 03. Myopia (Near-Sightedness) [8].

References

7. Myopia (nearsightedness). Available from: https://www.aoa.org/healthy-eyes/eye-and-vision-conditions/myopia?sso=y.

8. myopia. Available from: https://www.britannica.com/science/myopia.

(05): 00:31:18 Eye Safety & Protection; Eye Hygiene

The human eyes possess a high degree of sensitivity, particularly the retina, which is a neural tissue that is susceptible to neurodegenerative ailments and injuries. Even minor trauma can result in severe damage to the retina. Individuals employed in industrial settings, engaged in metal grinding activities, or even those involved in gardening may be at risk of ocular injury due to exposure to fungal agents present in dirt particles that may compromise the integrity of the eyes. Ocular injuries are a commonly observed occurrence in various occupational settings. As per the National Institute for Occupational Safety and Health (NIOSH), an estimated 2,000 American laborers experience ocular injuries while on the job on a daily basis, which requires medical attention. As per safety experts and medical professionals with specialization in ophthalmology, the judicious utilization of eye protection gear has the potential to curtail nearly 90% of ocular injuries, either by mitigating their intensity or forestalling them entirely. The incidence of ocular injuries in occupational environments is a commonly observed phenomenon that can be ascribed to exposure to foreign substances or objects, as well as corneal abrasions. Frequent ocular injuries comprise occurrences of fluid infiltration into the eye, thermal burns resulting from exposure to steam, and the consequences of ultraviolet or infrared radiation. Moreover, professionals employed in healthcare, laboratory, janitorial services, and other relevant fields face the possibility of acquiring contagious illnesses via ocular exposure. Several infectious diseases possess the capability to spread through the mucous membranes that surround the ocular region. Transmission can occur through various modes, such as direct contact with blood splashes, inhalation of respiratory droplets generated during coughing, or ocular exposure to contaminated objects or fingers [9].

Maintaining proper hygiene of our eyes is crucial for ensuring optimal ocular health. Adherence to appropriate eye hygiene practices is crucial for maintaining optimal ocular health. Inadequate compliance with ocular hygiene protocols may lead to ocular pruritus, inflammation, and xerophthalmia. The condition mentioned above is referred to as blepharitis in medical terminology. Prolonged periods of inadequate hydration can result in notable dehydration, heightened susceptibility to infections, ocular inflammation referred to as styles, and the formation of chalazion cysts. Ensuring ideal ocular hygiene is imperative for maintaining optimal eye health. Observing proper ocular hygiene protocols can considerably decrease the probability of acquiring bacterial infections, suffering from severe ocular dryness, and manifesting persistent ocular redness. Following proper eye hygiene protocols leads to attaining hygienic eyelids that exhibit strong visual and tactile sensitivity [10].

References

9. Protecting your eyes at work. Available from: https://www.aoa.org/healthy-eyes/caring-for-your-eyes/protecting-your-vision?sso=y.

10. Eye Hygiene (Eyegiene) for Better Eye Health. Available from: https://mydryeye.ca/eye-hygiene-eyegiene-for-better-eye-health/.

(06): 00:40:07 Adults & Eye Exams; Optometrist vs Ophthalmologist

The responsibility of optometrists is to provide primary healthcare services related to the visual system. Upon completion of their undergraduate studies, the individual pursued a rigorous four-year optometry program, culminating in the attainment of a Doctor of Optometry degree. Certain optometrists opt to pursue supplementary clinical education or accomplish a specialized fellowship program subsequent to the attainment of their optometric studies. Their professional activities primarily focus on standard visual healthcare, which involves conducting comprehensive eye examinations and administering various visual assessments. The term "ophthalmic dispensing" pertains to the proficient application of prescribing and fitting remedial eyewear, such as spectacles and contact lenses. It is imperative to monitor ocular disorders that are medically associated with conditions such as diabetes. Effectively provide and execute therapeutic interventions for ocular conditions, including Dry Eye Syndrome and glaucoma. The recommended approach to addressing visual impairments entails the provision of low-vision aids and vision therapy [11].

A healthcare professional who has obtained specialized education and training to diagnose, treat, and manage conditions relating to vision and the eyes is known as an eye doctor or ophthalmologist. Ophthalmologists are medical or osteopathic practitioners who are committed to giving their patients comprehensive eye care. Regarding their academic standing and propensities for diagnosing and treating pathological disorders, professionals in the fields of ophthalmology, optometry, and opticianry set themselves apart from one another. A specialist in ophthalmology is qualified to practice medicine and perform surgery within the confines of their license after completing the fundamental prerequisites for getting a college degree and at least eight years of medical school. You can read, write, and see up close and from a distance whether you're an adult or adolescent without glasses if you don't have any eye health issues. You don't need to see an eye doctor or other healthcare provider if you don't experience eye pain or pain around the eye. The ophthalmologist will also perform a thorough screening exam, check your eye pressure, and examine the surface of your eyes to ensure everything is in good condition [12].

Figure 05. Ophthalmologists [13].

References

11. Eye Doctors: Optometrists and Ophthalmologists. Available from: https://www.webmd.com/eye-health/eye-doctors-optometrists-ophthalmologists.

12. Difference between an Ophthalmologist, Optometrist, and Optician. Available from: https://aapos.org/glossary/difference-between-an-ophthalmologist-optometrist-and-optician.

13. Ophthalmologist: Definition and Overview. Available from: https://www.diabetesselfmanagement.com/diabetes-resources/definitions/ophthalmologist/.

(07): 00:46:35 Presbyopia (Age-Related Vision Decline), Reading Glasses

Presbyopia, an age-related eye disorder, makes it difficult for people in their middle years and older to focus on little details. It happens when the lens, an inner eye component that helps with eye focus, does not adequately illuminate the retina, a light-sensitive layer of tissue at the rear of the eye. If you have presbyopia, your eye muscles are unable to unwind and adjust the lens. Additionally, we are no longer able to turn back the lens or switch the focus from close to far [14]. Long-term age-related presbyopia is characterized by a decrease in ocular flexibility. The process through which the eye improves the crystalline lens' ability to focus adjacent objects on the retina is referred to as accommodation. The decrease in accommodating power is particularly obvious between the ages of 20 and 50. According to a study, over the first 20 years of life, the accommodative amplitude, which normally falls between 7 and 10 diopters, remains constant. By the age of 50, the accommodating amplitude typically drops to 0.50 diopters. This degradation, which is a typical side effect of aging, will eventually occur in everybody who lives to sufficiently old age. Even though its cause is yet unknown, presbyopia is a disease that many individuals experience. Presbyopia is primarily brought on by aging, however, several systemic diseases, drugs, and trauma can trigger an early loss of accommodative capacity. According to the FDA, the topical medication pilocarpine 1.25% can now be used to treat presbyopia, a condition that was previously believed to be incurable. According to studies, humans can adapt to low light conditions by gaining up to three lines of near and intermediate vision without losing more than one line of far vision. After implantation, the effects begin 15 minutes later and last for 6 hours. A mild headache and some eye burning were present [14].

According to several studies, it has been observed that young adults who use reading glasses tend to demonstrate a tendency towards over-accommodation during the execution of visual tasks. This underscores the significance of precise measurement in ascertaining an individual's authentic accommodative posture. Young adults who use reading glasses with a power of +2D and +3D exhibit a condition of over-accommodation when performing visual tasks that require focusing on a plane located in front of the intended target [15].

Figure 06. Presbyopia [16].

References

14. Presbyopia. Available from: https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/presbyopia#:~:text=What%20is%20presbyopia%3F,the%20back%20of%20the%20eye).

15. Shapiro, J.A., J.E. Kelly, and H.C. Howland, Accommodative state of young adults using reading spectacles. Vision Research, 2005. 45(2): p. 233-245.

16. Presbyopia – A Common Eye Condition Related to Aging. Available from: https://irisvision.com/presbyopia-common-eye-condition-related-to-aging/.

(08): 00:54:54 Reading Glasses: Use & Recommendations

The utilization of reading glasses can provide benefits to individuals who encounter challenges in perceiving objects situated nearby. Presbyopia is a commonly occurring age-related condition that can provide substantial advantages to individuals aged 40 years and above who utilize corrective eyeglasses. Presbyopia is a physiological phenomenon that is associated with the aging process, leading to a decrease in the accommodative amplitude of the eyes. This refers to the ability to adjust and focus on objects located nearby. Age-related alterations are a commonly observed phenomenon that usually becomes apparent in individuals during their initial to middle forties. The state's gradual deterioration is often ascribed to the natural phenomenon of aging, which commonly reaches its apex at approximately 65 years of age. There is no evidence of any deleterious consequences linked to the extended use of reading glasses within a particular population. However, a considerable percentage of these individuals have been administered medication with low potency or magnitude, which does not impede their daily functioning. It is a fact that a minor prescription can improve the acuity of particular visual stimuli, leading to enhanced perception of the surrounding environment with greater precision. Using reading glasses as a prolonged visual aid for a higher prescription is not advisable [17].

References

17. Is It OK to Wear Your Reading Glasses All the Time?; Available from: https://trueeye.com/is-it-ok-to-wear-reading-glasses-all-the-time/#:~:text=Who%20Should%20Use%20Reading%20Glasses,focus%20on%20close%2Dup%20objects.

(09): 00:58:34 Night Vision & Glasses

The implementation of yellow lenses leads to a decrease in the amount of light that penetrates the eye, resulting in a subsequent decrease in visual clarity. In situations where there is a decrease in illumination, the outcome may be disadvantageous rather than beneficial. A diverse spectrum of yellow and amber hues are available for spectacles designed for nocturnal driving. Empirical evidence suggests that there exists a direct correlation between the level of tint present in lenses and their efficacy in mitigating the effects of glare. Nevertheless, lenses that possess a considerable degree of tint lead to a marked reduction in the transmission of light, impeding visibility in settings that lack adequate illumination. Based on anecdotal accounts, a specific cohort of individuals who utilize spectacles specifically crafted for nocturnal driving have purported a perceived enhancement in their visual acuity while operating a vehicle during nighttime hours while wearing said glasses. The findings of the visual evaluations suggest that there is no discernible improvement in visual sharpness or the ability to detect pedestrians when utilizing night driving glasses as opposed to abstaining from their usage while driving at night. According to a 2019 study, the use of night driving glasses was found to cause a slight delay in visual reflexes, resulting in a minor decline in nighttime vision [18].

References

18. Night Driving Glasses: Do They Work?; Available from: https://www.healthline.com/health/night-driving-glasses.

(10): 01:03:54 Corrective Eye Glasses, Exercises

A distinction can be made between the intraocular muscles that are accountable for the relaxation and refocusing of the lens and the extraocular muscles that regulate the motion of the eyeballs. Intermittent esotropia is a type of strabismus that is distinguished by the inward deviation of the eye towards the nasal side. This specific type of strabismus exhibits the potential for efficient control during a substantial portion of the daily cycle. However, it is a prevalent occurrence that emerges in situations that trigger stress or prolonged periods of tasks requiring concentrated visual attention [19].

This task functions by administering a challenge to an individual that assesses their capacity to sustain extended periods of focus. It is recommended to perform the activity in a seated position. Extend your index finger a short distance from your eye. Please focus your attention on your finger. Slowly remove your finger from your face while keeping your focus. Shift your visual attention from the current fixation point to a remote location. Focus your attention on your outstretched digit and gradually bring it nearer to your ocular organ. A commonly suggested strategy involves the act of shifting one's visual focus and subsequently directing it towards an object positioned at a distant site. Perform three iterations. The occurrence of ocular fatigue is a frequently observed phenomenon that impacts a significant segment of the overall populace. The human visual system does not endorse the practice of prolonged fixation on a single object as an optimal mode of operation. The implementation of the 20-20-20 guideline displays promise in mitigating the effects of visual discomfort experienced by individuals who participate in prolonged computer usage throughout the day. To operationalize this particular directive, it is recommended that individuals conform to a structured regimen of interrupting their work every 20 minutes and shifting their attention towards an object located at a distance of 20 feet for 20 seconds [20].

Figure 07. Eyes Visual focusing [21].

References

19. de Decker, W., E. de Decker Dannheim, and U. Backheuer, Intermittent esotropia. Strabismus, 2008. 16(4): p. 145-8.

20. Eye Exercises: How-to, Efficacy, Eye Health, and More. Available from: https://www.healthline.com/health/eye-health/eye-exercises.

21. Predicting Human Visual Attention. Available from: http://fotisliarokapis.blogspot.com/2010/07/predicting-human-visual-attention.html.

(11): 01:09:52 Near-Far Exercise & Presbyopia; Smooth Pursuit Exercise & Concussion

The physical exercise referred to as Near-Far Exercise can be performed statically, either in a standing or seated posture. Place your thumb at an approximate distance of 10 inches from your face and focus your visual attention on it. Kindly direct your attention towards an object or entity that is currently positioned within a distance of 10 to 20 feet from your current location. Periodically shift between near and far focal points for 2-3 minutes. Several research studies have indicated that the eye exercise specifically developed for presbyopia did not exhibit a noteworthy enhancement in either accommodation or near visual acuity. The findings of the study indicate a rise in miosis, denoting the reduction in the diameter of the pupil, during the observation of objects nearby. This implies the possibility of improving contentment with visual acuity at close distances. Additional investigation is required to examine the fundamental mechanisms and improve the exercise regimen for improved results [22].

The results of the study indicate that individuals who have experienced a sport-related concussion (SRC) demonstrate altered patterns of eye movement during a task that simulates a sporting activity, as compared to the group of individuals who have not experienced SRC. Subjects categorized as SRC exhibit a reduction in the speed of their smooth pursuit eye movements (SPEMs). The authors have demonstrated a compensatory mechanism wherein the size and speed of saccades are increased to maintain visual fixation. The above-mentioned results emphasize the importance of assessing the movement of the eye in situations that replicate real-life circumstances. The current assessment possesses the capability to function as a biological indicator for concussions and provide noteworthy understandings regarding the management of eye movements following concussions incurred during athletic activities. Further exploration in this field can enhance understanding and management of visual impairments linked to concussions resulting from sports activities [23].

Figure 08. Exercise for Presbyopia [24].

References

22. Tsuneyoshi, Y., K. Negishi, and K. Tsubota, Multifaceted Assessment of the Effects of an Eye Exercise for Presbyopia. Rejuvenation Res, 2021. 24(6): p. 417-423.

23. Murray, N.G., et al., Smooth Pursuit and Saccades after Sport-Related Concussion. J Neurotrauma, 2020. 37(2): p. 340-346.

24. Eye Exercises for Presbyopia. Available from: https://www.rebuildyourvision.com/blog/vision-conditions/presbyopia/eye-exercises-for-presbyopia/.

(12): 01:13:25 Supranormal Vision & Performance Training

The term "Supranormal Vision & Performance Training" pertains to a set of training methodologies and interventions that have been devised to augment visual abilities beyond the conventional spectrum. The aforementioned techniques have been developed to enhance visual performance, refine visual aptitudes, and potentially attain extraordinary visual proficiencies.

Intermittent Exotropia (IXT) and vision therapy:

Currently, there is an ongoing exploration of the possibility of integrating objective eye movement recordings and biofeedback into vision therapy as a prospective method for managing intermittent exotropia (IXT), which is the most prevalent type of exotropia observed during childhood. The objective of the therapy is to enhance patients' consciousness of ocular misalignment and instruct them on the technique of reestablishing the alignment of their eyes through biofeedback. Currently, a multi-center clinical trial is underway in the United States to evaluate the effectiveness of this vision therapy. The American Academy of Optometry has provided financial support for this study. The present study entails utilizing sophisticated eye movement recordings to assess the alignment and accommodation of the eyes, thereby enabling an unbiased appraisal of treatment efficacy [25].

Figure 09. Children with Intermittent Exotropia.

Visual Learning Enhancement and Brain Stimulation:

A study conducted at the University of Rochester investigated the efficacy of brain stimulation in facilitating visual perceptual learning. This research endeavor aimed to examine the impact of various forms of non-invasive brain stimulation on the acquisition and retention of visual perception skills among both healthy individuals and those with brain injuries. The findings indicate that the application of brain stimulation methods may augment the effectiveness of pedagogy and provide a potential avenue for ameliorating visual impairments resulting from cerebral trauma or stroke [26].

Figure 10. Visual Learning Enhancement Brain Stimulation [27].

References

25. An eye-brain connection. Available from: https://med.stanford.edu/ophthalmology/news-and-media/annualreport_2021/eye-brain.html.

26. Brain stimulation speeds up visual learning in healthy adults, and helps patients re-learn how to see. Available from: https://www.rochester.edu/newscenter/brain-stimulation-vision-loss-stroke-traumatic-injury-384142/.

27. DEEP BRAIN STIMULATION. Available from: https://www.precisionhealth.com.au/healthcare-services/advanced-neurosurgery-spinal-surgery/procedures-and-surgery/deep-brain-stimulation/.

(13): 01:19:11 20/20 Vision; Visual Acuity

Visual acuity is the most common and organic way to gauge how well the visual system is functioning. The term "20/20" is commonly used colloquially to denote good eyesight because tests of visual acuity are routinely necessary for various industries to confirm whether a person can safely operate a vehicle or do their tasks. If your vision is worse than 20/20, you cannot read the smallest letter from 20 feet away. By measuring the ability to distinguish visual details at a distance of 20 feet, clinical examination is used to determine the degree of visual sharpness, or visual acuity. One of the most important aspects of vision examination is the diagnosis of visual abnormalities, including refractive anomalies such hyperopia, myopia, and presbyopia. Myopia is characterized by poorer close-range visual acuity, and hyperopia is characterized by superior far- and inferior near-sightedness. Visual potency includes a wider variety of characteristics, such as ocular coordination, depth perception, peripheral awareness, focusing ability, and chromatic vision, whereas visual acuity evaluations are restricted to the evaluation of the clarity and sharpness of vision at a certain distance. Juveniles frequently have their visual acuity tested to monitor their visual development. Early discovery of such issues can effectively stop them from getting worse [28].

Figure 11. 20/20 vision [29].

References

28.What Is Acuity of Vision? ; Available from: https://www.webmd.com/eye-health/what-is-acuity-of-vision.

29.What does it mean to have 20/20 vision? ; Available from: https://wefixeyes.co.nz/articles/what-does-it-mean-to-have-20-20-vision/.

(14): 01:24:51 Contact Lenses: Use, Risks & Aging

The use of soft contact lenses made of polymer gel has been observed to reduce the supply of oxygen to the cells on the surface of the eye. Studies have indicated that the younger demographic exhibits ample reserves of oxygen and tear film, enabling them to endure the aforementioned contact lenses without any notable challenges. Contact lenses offer distinct advantages over eyeglasses in terms of vision correction, owing to their ability to address various aspects of the eye's structure to attain optimal visual acuity. Astigmatism is an ocular aberration characterized by an irregularly shaped cornea or lens, resulting in an eye that assumes an oblong shape as opposed to a spherical one. Whilst glasses possess the capability to partially rectify this condition, the existence of high-order aberrations in either the cornea or lens may endure. The optical aberrations responsible for the focusing of light cannot be corrected solely through the use of spectacles. Research has demonstrated that utilizing a smooth contact lens on the corneal surface can be a viable strategy for mitigating aberrations. According to reports, individuals who utilize both glasses and contact lenses have reported a greater degree of visual acuity when using the latter as opposed to the former [30].

The tear film reserves of individuals tend to diminish with advancing age, leading to a decline in their ability to tolerate contact lenses. Furthermore, it is imperative to perform a thorough cleaning of contact lenses due to their susceptibility to the entrapment of microorganisms such as bacteria and fungi. The occurrence of a corneal infection due to contact lens usage can result in significant ramifications, such as corneal scarring and impaired visual acuity, persisting even after efficacious intervention. While infrequent, such incidents can present difficulties in their handling. Healthcare experts recommend that individuals who use contact lenses exercise prudence in monitoring their tolerance levels and strictly adhere to the prescribed guidelines for the usage and maintenance of the lenses.

Figure 12. Future of Contact Lenses [31].

References

30. Berntsen, D.A., et al., A Randomized Trial to Evaluate the Effect of Toric Versus Spherical Contact Lenses on Vision and Eyestrain. Eye Contact Lens, 2019. 45(1): p. 28-33.

31. The Contact Lenses Of The Future Will Improve Our Health. Available from: https://www.lenspure.com/articles/contact-lenses-future-improve-our-health.

(15): 01:31:34 UV Protection & Cataracts, “Blue Blockers”

It is imperative to distinguish that ultraviolet (UV) light is positioned adjacent to blue light on the electromagnetic spectrum, while red light is situated at the opposite extremity. The infrared region, situated beyond the red light spectrum, is undetectable by the human visual system. Both UV light and infrared light are imperceptible to the human visual system. The adverse effects of UV radiation on human health, specifically in regards to skin health, are widely acknowledged in academic literature. Therefore, it is imperative for individuals to adopt strategies to minimize their susceptibility to UV radiation, as it has the potential to cause skin burns. In addition, extended exposure to UV radiation has adverse impacts on ocular well-being. More specifically, prolonged exposure to this substance the ocular surface and has the potential to induce the formation of cataracts, a condition characterized by the oxidative degradation of the lens located within the eye. Moreover, under specific circumstances, UV radiation has the potential to induce harm to the retina. The utilization of UV protection glasses is imperative to alleviate the negative repercussions outlined previously. Blue blocker glasses possess unique attributes that differentiate them from other forms of eyeglasses. In contrast to their traditional counterparts, which primarily consisted of glass, contemporary glasses are primarily constructed using plastic materials. Nevertheless, it is crucial to acknowledge that both categories of glasses exhibit the capacity to selectively screen UV radiation. Blue blockers refer to a specific category of eyewear that undergoes a chemical reaction when exposed to sunlight, leading to the tinting or darkening of the lenses. The aforementioned reaction is specifically initiated by the UV wavelength, thereby affording regard safeguard against solar radiation [32].

Figure 13. UV Protection & Cataracts [31].

References

32. Roberts, J.E., Ultraviolet radiation as a risk factor for cataract and macular degeneration. Eye Contact Lens, 2011. 37(4): p. 246-9.

(16): 01:38:20 Light Sensitivity & Eye Color

Individuals possessing blue or light-colored irises exhibit a heightened susceptibility to photophobia. The phenomenon under observation can be ascribed to the inherent fluctuations in the iris muscles, which govern the regulation of the pupil's contraction and expansion in reaction to alterations in the surrounding light levels. In order to provide a visual demonstration, when an individual seeks medical attention for their eyes and undergoes a dilated examination, ophthalmic drops are administered to induce the dilation of the pupils. The procedure entails modifying the neural impulses in the iris muscle, leading to the expansion of the iris and the subsequent widening of the eye's aperture. The duration of pupil dilation in individuals with blue, hazel, or light-colored eyes have been observed to be four, six, or eight hours individuals must adapt to hurts to the application of eye drops. On the other hand, there exists empirical evidence indicating that individuals possessing brown irises exhibit a comparatively abbreviated period of pupillary dilation, with a duration of approximately sixty minutes. Researchers have conducted observations pertaining to the disparities in the attributes of irises, muscles, and potentially the associated innervating nerves between individuals with light-colored eyes and those with darker-colored eyes. These disparities could potentially be linked to variations in the perceived level of sensitivity among certain individuals. Individuals who exhibit diminished pupillary constriction in the presence of intense light are more likely to perceive such light as highly bothersome and distressing [33].

References

33. Nischler, C., et al., Iris color and visual functions. Graefes Arch Clin Exp Ophthalmol, 2013. 251(1): p. 195-202.

(17): 01:40:29 LASIK Eye Surgery

LASIK eye surgery is the most popular laser refractive technique for vision repair. Laser-assisted in situ keratomileusis (LASIK) may replace glasses or contacts. LASIK surgery uses a laser to precisely change corneal curvature. This method targets the cornea, a transparent, convex tissue at the front of the eye. This surgery improves vision. The cornea bends light precisely onto the retina in people with normal visual acuity. However, myopia, hyperopia, and astigmatism affect light bending, causing blurred vision. Refraction-correcting glasses and contacts are used for eyesight correction. However, corneal curvature modification can achieve the desired correction. LASIK surgery could treat and manage many visual problems. Myopia, often known as nearsightedness, is a refractive defect that impairs vision. When the eyeball's axial length is longer than average or the cornea is curvy, light rays converge anterior to the retina, causing blurred vision of distant objects. Visual perception shows that nearby things are clearer than distant ones. Hyperopia is a refractive defect that affects vision. Light is refracted beyond the retinal surface when the eyeball's axial length is shorter than typical or the corneal curvature is flat. This decreases visual acuity for nearby and distant objects. Astigmatism is a refractive error caused by corneal irregularity. This aberration impairs the visual system's ability to focus on proximal and distal objects [34].

Figure 14. LASIK Eye Surgery.

References

34. Solomon, K.D., et al., LASIK world literature review: quality of life and patient satisfaction. Ophthalmology, 2009. 116(4): p. 691-701.

(18): 01:46:26 Dry Eye, Tears & Age

As individuals progress in age, a discernible decline in both the quantity and quality of tears produced becomes evident. Tears consist of two primary components: a saline solution produced by the lacrimal gland, and a continuous release of these tears onto the ocular surface. Additionally, reflex tearing can be observed in response to various stimuli, including the presence of an eyelash in the eye or emotional crying. These stimuli prompt the lacrimal glands to increase the secretion of saline tears onto the ocular surface. The Meibomian gland, located within the eyelid, is responsible for the secretion of tears that contain an oily component. The oily substance in question fulfils a dual function by forming a protective barrier over the aqueous component of the tear film and subsequently integrating itself into the tears. As an individual undergoes the process of To, there is an observable decrease in the quantity of both the aqueous and oil components of tears. It is noteworthy that the oil component demonstrates a relatively rapid decline. Artificial tears that are readily accessible in the market are specifically formulated for ocular use and generally comprise a saline solution that closely mimics the chemical composition of natural tears. Research has indicated that the act of visually perceiving computer screens or engaging in the activity of reading books has been observed to exert a suppressive influence on the production of tears in the human ocular system. The lipid constituent of tears serves a crucial function in maintaining tears within the ocular cavity by forming a surface layer on the aqueous medium. Continual investigation is currently underway to chemically produce the lipid component found in tears, given its significant functional importance. There exist two potential approaches for attaining this desired result: the artificial synthesis of the lipid constituent of tears, or the restoration of functionality to the meibomian glands located in the ocular region [35, 36].

References

35. de Paiva, C.S., Effects of Aging in Dry Eye. Int Ophthalmol Clin, 2017. 57(2): p. 47-64.

36. Sharma, A., et al., Gene Therapy for the Cornea, Conjunctiva, and Lacrimal Gland, in Encyclopedia of the Eye, D.A. Dartt, Editor. 2010, Academic Press: Oxford. p. 185-194.

(19): 01:53:24 Dry Eye, Serum Tears & Preservative-Free Artificial Tears; PRP

Ensuring proper eyelid hygiene is imperative for the optimal functioning of the oil glands, which in turn promotes the production of high-quality tears. The significance of mitigating inflammation, irrespective of its etiology, including allergies, cannot be overemphasized. The occurrence of dry eyes is frequently intensified in individuals during the spring season as a result of the manifestation of seasonal allergies. Eye drops exhibit anti-inflammatory properties that effectively alleviate the symptoms associated with inflammation. The present area of inquiry within the domain of ocular treatment pertains to the examination of the complexities associated with corneal and ocular surface nerves. The aim of this study is to augment our comprehension of these neural pathways and investigate potential approaches to enhance their therapeutic effectiveness. Moreover, there is an increasing scholarly focus on the revitalization of the nerves and tissue cells situated beneath the tear film. In specific instances, the blood serum of individuals is employed as a therapeutic agent owing to its abundant concentration of growth factors. The topic at hand is related to Protein rich Plasma or PRP, albeit beyond the purview of PRP proper. The methodology entails the retrieval of blood from the individual, subsequently accompanied by the separation of blood cells through centrifugal force. The aforementioned procedure involves the separation of the fluid constituent of the blood, commonly referred to as serum. The serum is subsequently diluted using a solution containing saline and preservatives. The resultant blend has the potential to be preserved in a freezer and employed as a form of ocular medication. The efficacy of this therapeutic approach has been shown to offer notable benefits for individuals afflicted with severe dry eye syndrome. Individuals experiencing dry eye symptoms are advised to consider using preservative-free eye drops as a precautionary measure against the potential hazard of bacterial contamination commonly associated with eye drops that contain preservatives. In certain instances, the application of the preservative has the potential to elicit inflammation on the ocular surface of the human eye. A concerning incident occurred in the state of Florida, located in the United States, where a clinic administered stem cell injections to the ocular regions of patients in an attempt to restore visual acuity. Unfortunately, the implementation of this procedure led to an unforeseen outcome wherein the individuals affected experienced irreversible visual impairment. PRP is characterized by a significant presence of growth factors, which are hypothesized to be responsible for its observed impact on tissue rejuvenation. Nevertheless, it is crucial to acknowledge that PRP has not yet achieved the designation of a universally accepted treatment protocol, especially within the realm of ophthalmology, due to the ongoing investigation being carried out in this domain [37].

Figure 15. PRP Production [38].

References

37. Rawat, P., et al., Autologous platelet-rich plasma eye drop versus artificial tear eye drop for symptomatic dry eye disease: A prospective comparative interventional study. Indian J Ophthalmol, 2022. 70(5): p. 1549-1553.

38. Yogev, Y., A humoral solution: Autologous blood products and tissue repair. Cellular Immunology, 2020. 356: p. 104178.

(20): 02:00:46 Vision Loss: Cataracts, Glaucoma

Refractive error is identified as the primary underlying factor contributing to low vision. It is worth noting that individuals who require corrective eyewear, particularly those residing in certain nations, may encounter challenges in accessing appropriate glasses. Consequently, refractive error represents a correctable condition associated with low vision. Cataract refers to the progressive deterioration of the lens located within the ocular structure, specifically positioned behind the cornea, resulting in visual impairment. Cataracts are a common occurrence in individuals who have reached the age of 100 or 110 years old or below, as it is a natural part of the have process. At a certain stage, cataracts reach a severity that necessitates their surgical removal. Cataract surgery is a relatively brief procedure involving the insertion of a plastic or clear plastic lens into the eye's intraocular space, precisely replacing the natural lens. Additionally, there exist lenses capable of accommodating both near and far light focusing, indicating that cataract treatment has essentially reached a resolved state. Cataracts, despite being a highly treatable condition, ranks second among the leading causes of vision loss worldwide due to inadequate access to healthcare services [39].

Glaucoma is recognized as the leading cause of global vision impairment, encompassing a constellation of diseases that are collectively classified as such. This ocular condition shares similarities with degenerative disorders, including neurodegeneration observed in Alzheimer's disease. Glaucoma is a condition that impacts the optic nerves, which serve as the conduit between the eyes and the brain. The optic nerves are responsible for transmitting visual information from the eyes to the brain. In the context of glaucoma, it is possible for the optic nerve to undergo degeneration, which can lead to conditions such as optic nerve stroke and inflammatory diseases like multiple sclerosis. Similar to how a spinal cord injury results in paralysis, degeneration of the optic nerve leads to irreversible loss of vision. Glaucoma is a condition that manifests across various age groups, although it predominantly affects individuals aged 50, 60, or 70 and above. The likelihood of developing glaucoma is heightened with the process of aging. Also, Glaucoma can be induced by elevated intraocular pressure [39].

References

39.Glaucoma and Cataracts. Available from: https://www.glaucomaassociates.com/glaucoma-and-cataracts/.

(21): 02:09:23 Age-Related Macular Degeneration, Dry & Wet Forms

Age-related macular degeneration (AMD) is a visual disorder that is distinguished by the degradation of central visual acuity, which occurs due to damage to the macula. This disease has a detrimental impact on the macula, which plays a crucial role in enabling accurate and focused vision. AMD is a common cause of visual impairment in older individuals, resulting in difficulties in facial recognition, reading, driving, and performing tasks that require sharp visual acuity. AMD demonstrates heterogeneity in the rates of progression across individuals, with certain individuals displaying a gradual progression while others manifest a more rapid decline. Therefore, it is essential to regularly undergo ocular examinations as they play a pivotal role in the timely identification of AMD. A significant proportion of individuals who receive a diagnosis of AMD present with dry AMD, which is distinguished by the gradual deterioration of the macula due to the natural process of aging. AMD is characterized by three distinct stages: early, intermediate, and late. The disease demonstrates a gradual progression over several years. Late-stage dry AMD is currently devoid of definitive treatment. Nevertheless, there are strategies available to enhance the utilization of the remaining visual capabilities. Individuals diagnosed with advanced dry AMD in one eye have the opportunity to employ strategies aimed at protecting their unaffected eye. Wet AMD, also known as advanced neovascular AMD, is a less common variant of the disease that is typically associated with a more accelerated decline in visual acuity. The progression from any stage of dry AMD to the advanced form, commonly referred to as wet AMD, is a plausible occurrence. Nevertheless, it is crucial to acknowledge that wet AMD commonly manifests in the advanced phases of the ailment. Fortunately, there exist various treatment options that are accessible to individuals who have been diagnosed with AMD. The presence of symptoms related to AMD depends on the stage of the disease. In the early stage of dry AMD, there are no noticeable symptoms. In the context of intermediate dry AMD, individuals may present with a variety of manifestations. While it is possible for some individuals to exhibit no symptoms, others may experience mild symptoms such as blurred central vision or challenges in perceiving objects in low-light conditions. In the later stages of eyes AMD, individuals may exhibit the perceptual distortion of straight lines, characterized by a waviness or crookedness. Furthermore, a hazy area near the central visual field may arise, exhibiting the possibility of enlarging or manifesting as an absence. The perception of colors may demonstrate a reduction in vibrancy, while visual acuity in poorly illuminated settings may be impaired [40].

Figure 16. Macular degeneration [41].

References

41. Hara, C., et al., Refractory Age-Related Macular Degeneration Due to Concurrent Central Serous Chorioretinopathy in Previously Well-Controlled Eyes. 2023. 16(1): p. 89.

(22): 02:14:02 Diabetic Retinopathy, Type I vs Type II Diabetes

Diabetic retinopathy is a pathological condition affecting the eyes, which carries the risk of causing visual impairment and total blindness in individuals suffering from diabetes. This phenomenon affects the blood vessels in the retina, a light-sensitive tissue situated at the posterior region of the eye. It is essential for individuals diagnosed with diabetes to undergo a comprehensive dilated eye examination. This is because the timely detection of potential ocular complications can significantly contribute to the preservation of their visual well-being. The effective management of diabetes-related vision impairment can be achieved through the implementation of physical activity, adherence to a nutritious diet, and appropriate medication regimens. These interventions have the potential to not only mitigate the risk of vision impairment but also delay its onset. In the early stages of diabetic retinopathy, individuals may not manifest any discernible symptoms. Nevertheless, as the disease advances, it may cause the extravasation of blood vessels into the vitreous humor, resulting in the manifestation of dark spots or streaks that exhibit a floating motion within the visual field. The administration of therapeutic interventions is of utmost significance to mitigate the development of scars in the posterior segment of the eye and to prevent the recurrence of hemorrhaging. Diabetic retinopathy possesses the capacity to engender supplementary ocular complications, such as diabetic macular edema (DME). DME is distinguished by the extravasation of fluid from blood vessels into the macula, leading to compromised visual acuity. Neovascular glaucoma, a type of ocular pathology that has the potential to cause visual impairment and complete vision loss, can also occur as a result of diabetic retinopathy. Furthermore, retinal detachment, a pathological condition characterized by the development of fibrous tissue in the posterior segment of the ocular globe, presents an additional potential outcome. It is imperative to obtain medical care and proficiently control diabetes to mitigate the onset or delay of the occurrence of visual impairment [42].

References

42. Diabetic Retinopathy. Available from: https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/diabetic-retinopathy#:~:text=Diabetic%20retinopathy%20is%20an%20eye,at%20least%20once%20a%20year.

(23): 02:18:54 Diabetic Retinopathy Treatment, Blood Pressure

There are multiple strategies available for the mitigation of risks associated with Diabetic retinopathy. First and foremost, it is crucial to undergo regular eye examinations. Furthermore, the proficient administration of diabetes and the preservation of ideal blood glucose levels are crucial elements in managing the advancement of this ailment. The aforementioned phenomenon has been documented through rigorous empirical research, wherein individuals who demonstrated effective management of their diabetes experienced a significant reduction in the occurrence of diabetic retinopathy. Individuals exhibiting heightened blood pressure levels may encounter detrimental consequences on their retinal tissue, resulting in the onset of a medical condition commonly referred to as Diabetic Retinopathy. To optimize the management of blood glucose levels, it is crucial to prioritize the regulation of blood pressure [43].

Figure 17. Normal retina vs Diabetic retina.

References

43. Liu, L., et al., Hypertension, blood pressure control and diabetic retinopathy in a large population-based study. PLoS One, 2020. 15(3): p. e0229665.

(24): 02:22:17 Glaucoma Screening & Treatment

The accurate identification of glaucoma requires a comprehensive evaluation of the ocular region performed by a medical professional. The comprehensive examination typically includes a range of assessments, including the quantification of intraocular pressure, the evaluation of optic nerve dysfunction, the assessment of visual field abnormalities, the determination of corneal thickness, and the examination of the drainage angle. The management of glaucoma entails the implementation of diverse strategies aimed at lowering intraocular pressure. These methods include the utilization of prescribed ophthalmic drops, oral medications, laser therapy, surgical interventions, or a combination of these therapeutic modalities. Prescription ophthalmic medications consist of a wide array of therapeutic agents, including prostaglandins, beta blockers, alpha-adrenergic agonists, carbonic anhydrase inhibitors, rho kinase inhibitors, and miotic or cholinergic agents. The aforementioned medications possess the capacity to reduce intraocular pressure and are linked to potential negative consequences, such as ocular redness and discomfort, headaches, ocular pain, pupil constriction, visual impairment characterized by blurred or diminished clarity, and myopia. To minimize the extent of systemic absorption of ophthalmic medication, it is advised to keep the eyes closed for a period of 1 to 2 minutes following the administration of the medication. Furthermore, it has been observed that the application of mild pressure at the medial canthus, specifically near the nasolacrimal duct, for a duration of 1 to 2 minutes can facilitate the occlusion of the lacrimal punctum. To mitigate the risk of subsequent absorption, it is imperative to effectively remove any remaining droplets on the eyelid. It is advisable to adhere to a minimum time interval of five minutes when administering distinct ocular medications or utilizing artificial tears, particularly in situations where multiple eye drops have been prescribed or are necessary. Pharmacological interventions, such as the oral administration of medications, may be recommended as a viable strategy to effectively alleviate the symptoms commonly associated with glaucoma. It is crucial to adhere to appropriate hygiene practices and avoid the simultaneous use of multiple eye drops or artificial tears [44].

References

44. Glaucoma. Available from: https://www.mayoclinic.org/diseases-conditions/glaucoma/diagnosis-treatment/drc-20372846#:~:text=But%20treatment%20and%20regular%20checkups,or%20a%20combination%20of%20approaches.

(25): 02:28:07 Smoking, Vaping & Vision Diseases; Cannabis & Eye Pressure

The act of smoking poses a significant risk factor for the development and progression of macular degeneration, a condition characterized by the deterioration of the central portion of the retina and subsequent vision loss. Additionally, there exists a correlation between specific genes and the occurrence of macular degeneration. Consequently, engaging in smoking or vaping practices can have detrimental effects on ocular health, leading to impaired vision. E-cigarettes are commonly promoted as a potentially less detrimental alternative to traditional cigarettes. Nevertheless, recent studies have revealed that individuals who partake in vaping exhibit significant signs of ocular dryness, varying in severity from moderate to severe, alongside a decline in the quality of their tear film. Based on a recent study conducted in 2021 at the University of California, there exists empirical evidence indicating that individuals who presently partake in vaping activities exhibit a 34% increased probability of encountering visual impairments in comparison to those who refrain from engaging in such conduct. Likewise, individuals who have previously participated in vaping activities exhibit a 14% higher probability of experiencing visual impairments. The aforementioned correlation serves to bolster prior research findings that have established a link between tobacco smoking and ocular complications. Further investigation is necessary to improve understanding regarding the influence of electronic cigarettes on the health of the ocular surface. Also, cannabis can lower eye pressure which may undermine the progression of glaucoma and cannabis is also terrible for dry eyes [45].

Figure 18. Smoking causes Blindness.

References

45. Smoking Can Damage Eyesight – Vaping Isn’t Any Safer. Available from: https://assileye.com/blog/smoking-can-damage-eyesight-vaping-isnt-any-safer/#:~:text=Persons%20who%20vape%20showed%20moderate,who%20had%20never%20tried%20it.

(26): 02:35:13 Eye Pressure & Sleep Position

There exists a hypothesis positing that sleeping on the right eye may lead to a deterioration in the glaucoma condition of the right eye, potentially due to a slight elevation in intraocular pressure resulting from the downward positioning or potential compression against the pillow. The preferred sleeping position does not significantly impact one's health or well-being, even if an individual consistently tends to fall asleep on their left side. According to a recent study, there is evidence suggesting that individuals diagnosed with Parkinson's disease (PD) exhibit significant elevations in intraocular pressure (IOP) when assuming lateral and prone positions during sleep. The statistical analysis performed did not produce any statistically significant findings to substantiate a correlation between the dependency status and the observed fluctuations in IOP. The results of the study indicate that the prone position demonstrated a statistically significant increase in IOP in comparison to the lateral position. The probability of encountering a notable elevation in IOP while in a reclined posture may be augmented by the existence of three clinical factors: disk hemorrhage (DH), notches, and modifications in blood vessels (BV). Therefore, it is advisable for individuals who have been diagnosed with PD, as well as those who exhibit symptoms of PD syndrome (PDS) or PD glaucoma (PDG), to consider using a bed that allows for a 30° elevation of the head. There exists a potential for this intervention to alleviate the increase in IOP that is observed during periods of sleep [46].

References

46. Sedgewick, J.H., et al., Effects of different sleeping positions on intraocular pressure in secondary open-angle glaucoma and glaucoma suspect patients. Clin Ophthalmol, 2018. 12: p. 1347-1357.

(27): 02:37:48 Macular Degeneration, Optic Neuropathies & Red-Light Therapy

A research study was undertaken to examine the potential neuroprotective effects linked to red or near-infrared light. The results suggest that the application of this particular light stimulus can trigger neuroprotective mechanisms in the retina. The aforementioned hypothesis has been empirically validated through experimentation conducted on animal models, as well as a limited body of evidence from studies involving human participants. According to the research findings, the utilization of red or near-infrared light holds promise in providing benefits to individuals suffering from macular degeneration and optic neuropathies, such as glaucoma. The retinal ganglion cells are of significant importance in facilitating the transmission of visual information from the eyes to the brain. The claim that it demonstrates promise as a therapeutic modality is highly compelling. NIR light therapy, also known as photobiomodulation therapy (PBMT), demonstrates promise as a novel therapeutic approach for ocular conditions. The capacity of near-infrared (NIR) light to modulate the activities of cytochrome oxidase and superoxide dismutase suggests its potential to elicit metabolic and antioxidant effects. Moreover, prior research has provided empirical evidence that substantiates the potential efficacy of NIR light in enhancing cerebral blood flow and cognitive functioning in individuals, without any adverse effects. The literature review provides empirical evidence supporting the efficacy of NIR therapy and emphasizes its importance in the management of ocular disorders [47].

Figure 19. Optic Neuropathies [48]

References

47. Zhu, Q., et al., Near Infrared (NIR) Light Therapy of Eye Diseases: A Review. Int J Med Sci, 2021. 18(1): p. 109-119.

48. Biousse, V. and N.J. Newman, Diagnosis and clinical features of common optic neuropathies. The Lancet Neurology, 2016. 15(13): p. 1355-1367.

(28): 02:42:23 “Floaters”

During the process of birth, the central region of the eyes is characterized by the presence of collagen fibers that exhibit a gelatinous consistency. These fibers possess a predominantly transparent nature, thereby facilitating the unimpeded transmission of light toward the retina. Nevertheless, with the progression of age, these fibers and the accompanying gel-like substance experience a reduction in size and undergo a process of contraction, resulting in their detachment from the retina and aggregation within the central region of the eyeball. In contrast to the process of shrinkage, the structure of the eyeball itself remains unaltered, as it retains its original composition of a fluid or saline solution. As a result, the contraction of the gelatinous region results in the separation of minute retinal fragments that have minimal impact on visual perception. These fragments, in addition to minuscule tissue particles and concretions, are evident as floaters. These floaters commonly manifest as partially transparent or, in certain cases, slightly grayish tissue [49].

References

49. Fan, W.S., et al., Design of a Functional Eye Dressing for Treatment of the Vitreous Floater. J Pers Med, 2022. 12(10).

(29): 02:45:29 Eye Twitching

Eyelid myokymia, characterized by sporadic and mild ocular spasms, and benign essential blepharospasm, characterized by involuntary and prolonged contractions of the eyelid muscles, are prevalent conditions. Eye twitching is believed to be caused by various factors, including stress, ocular strain, pharmacological drugs, dryness or inflammation of the eyes, and insufficient sleep. Eyelid twitching is characterized by spasmodic contractions or involuntary blinking. Mild involuntary muscle contractions may become more pronounced, while severe involuntary muscle contractions can result in extended and vigorous closure of the eyelids lasting for seconds, minutes, or even hours. The process of diagnosing eye twitching aids in assessing the degree of its severity. It is advisable to consult a medical professional to evaluate eye discomfort and exclude potential causes such as blepharitis or neurological conditions including Bell's palsy, multiple sclerosis, dystonia, or Tourette syndrome. There exist various approaches that can effectively mitigate the occurrence of eye twitching. Several strategies that can be employed to promote overall well-being include ensuring an adequate amount of sleep, restricting the consumption of caffeine and alcohol, effectively managing stress levels, and utilizing artificial tears to address dry eyes. If ocular muscle spasms endure or impact the size of the eye-opening or the ability to perceive visual stimuli, it is advisable to seek the expertise of an ophthalmologist to explore potential courses of treatment. Botulinum toxin injections induce muscle relaxation and attenuation, thereby impeding the occurrence of spasms over three months. The administration of the treatment has the potential to result in minor bruising, eyelid ptosis, or diplopia. In instances where injections prove ineffective in managing symptoms of considerable severity, surgical intervention may be advised [50].

Figure 20. Causes of Eye Twitching [51].

References

50. Eye Twitching. Available from: https://www.hopkinsmedicine.org/health/conditions-and-diseases/eye-twitching.

51. Eye Twitching: Types, Causes, Symptoms, and Treatments. Available from: https://www.oscarwylee.com.au/glasses/eye/twitching-definition.

(30): 02:48:10 AREDS2 Supplementation & Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is an ocular condition characterized by the progressive decline of central vision. Numerous studies have provided evidence to support the effectiveness of incorporating specialized dietary supplements, particularly AREDS 2, in reducing the progression of visual impairment among individuals diagnosed with intermediate AMD affecting either unilateral or bilateral eyes. The efficacy of these dietary supplements resides in their capacity to hinder the progression of early AMD to intermediate AMD. However, the efficacy of these interventions in impeding the advancement from intermediate AMD to late AMD remains limited. To effectively monitor potential changes associated with early AMD, it is recommended that individuals undergo an annual dilated eye examination, as advised by their eye care professional. The Age-Related Eye Disease Study 2 (AREDS 2) has the potential to decelerate the progression of AMD in the contralateral eye in cases of unilateral late AMD. The efficacy of administering AREDS 2 supplements may be constrained in individuals who already present with bilateral late AMD. Nevertheless, the application of resources for individuals with impaired vision can contribute to the optimization of their residual visual capabilities. Individuals who have received a diagnosis of wet AMD, a form of advanced AMD, may have the option to employ alternative therapeutic approaches. The AREDS 2 supplements consist of substantial quantities of vitamins and minerals, potentially influencing digestive processes and the pharmacokinetics of other medications within the human body. The earlier iteration of AREDS supplements, referred to as "AREDS," incorporated beta-carotene, a component that has been associated with heightened susceptibility to lung cancer among individuals with a smoking history or who are presently engaged in smoking. To address this concern, it is advisable to contemplate the utilization of more modern iterations of AREDS 2 supplements that do not incorporate beta-carotene. The availability of AREDS 2 supplements is widespread, as they can be easily obtained from various brick-and-mortar pharmacies as well as online retailers. When making a selection of a dietary supplement, it is advisable to conduct a comprehensive analysis of the ingredient list to ascertain its inclusion of essential vitamins and minerals, accurately and in the specified quantities as indicated. Individuals should consult with a healthcare professional to acquire their professional assessment regarding the most suitable brand of AREDS 2 supplements for their particular requirements. The formulation of AREDS 2 supplements was derived from two distinct clinical trials, namely the Age-Related Eye Disease Studies (AREDS and AREDS2). The research study's findings suggest that individuals diagnosed with intermediate or late AMD who consistently consumed these supplements experienced a reduced likelihood of experiencing central vision loss [52].

References

52. AREDS 2 Supplements for Age-Related Macular Degeneration (AMD). Available from: https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/age-related-macular-degeneration/nutritional-supplements-age-related-macular-degeneration

(31): 02:53:39 Glaucoma & Vitamin B3 Supplementation

There are different clinical trials underway which studied Nicotinamide for Glaucoma, Like the Glaucoma Nicotinamide Trial (TGNT) is a research study that utilizes a prospective design, incorporating randomization and a placebo-controlled, double-masked methodology. The study encompasses two separate cohorts, namely the Swedish Glaucoma Nicotinamide Trial (SGNT) and the Vitamin B3 in Glaucoma Study (VBIGS). The research will utilize block randomization, stratified by glaucoma subtype, to assign patients diagnosed with open-angle glaucoma (OAG) into two separate groups. One group of participants will receive Nicotinamide, while the other group will receive a placebo [53].

The subsequent study will involve investigating various subpopulations of individuals who have been diagnosed with open-angle glaucoma, in addition to a control group consisting of individuals who are in a state of optimal health. The study participants will engage in two separate visits, with a two-week interval between each visit. During each visit, the participants will undergo blood collection and optical coherence tomography (OCT) examinations. During the interim period between the two visits, the participants will be administered a treatment regimen consisting of Nicotinamide at a dosage of 1.5g per day for the initial week, which will be followed by an increased dosage of 3.0g per day for the subsequent week [53]. However, it can be found from the entirety of the discussion that the supplementation of nicotinamide has the potential to enhance the functionality of the inner retina in individuals with glaucoma [54].

Figure 21. Glaucoma vs Normal Eye [55].

References

53. Nicotinamide and Glaucoma. Available from: https://clinicaltrials.gov/study/NCT05916066?cond=glaucoma&term=vitamin%20B3&rank=2.

54. Hui, F., et al., Improvement in inner retinal function in glaucoma with nicotinamide (vitamin B3) supplementation: A crossover randomized clinical trial. Clin Exp Ophthalmol, 2020. 48(7): p. 903-914.

55. Glaucoma: Definition and causes. Available from: https://www.allaboutvision.com/conditions/glaucoma/.

(32): 02:58:42 Retinal Imaging & Neurodegeneration Screening, Multiple Sclerosis

Immunomodulatory treatments for multiple sclerosis (MS) impede the activation, proliferation, and infiltration of immune cells into the central nervous system, encompassing the brain, spinal cord, and optic nerve. Neurodegeneration is associated with enduring disability, yet timely intervention mitigates relapses and enhances the quality of life. MS patients exhibited a significantly higher number of central nervous system inflammatory episodes as detected by magnetic resonance imaging (MRI) compared to relapses. In the majority of individuals diagnosed with relapsing-remitting MS, MRI) activity may manifest before the onset of clinical impairment. Immunomodulatory medications have the potential to initially reduce relapses and improve quality of life. However, it is important to note that in the absence of treatment, long-term disease progression, specifically during the secondary progressive phase, persists. The deterioration of clinical impairment is observed to be more pronounced in individuals experiencing a decline in brain capacity and an increase in disease burden during the secondary progressive phase. The absence of effective therapeutic interventions for secondary progressive MS underscores the importance of accurately identifying neurodegeneration as a fundamental step toward the development of viable treatment strategies. The condition of disability is exacerbated by the degeneration of the thalamus. The optic nerve transmits myelinated axons to the thalamus. The comprehension of the impairment to white matter networks that extend to the thalamus is crucial for the ability of neuroprotective treatments to anticipate multiple sclerosis (MS) neurodegenerative mechanisms. The experimental evaluation of MS treatments was conducted by the DeSilva Laboratory using in vivo models. In the acute phase, immune cells infiltrate the white matter of the spinal cord and the optic nerve, resulting in the loss of myelinated axons. The axonal degeneration of spinal cord neurons and retinal ganglion cells was observed exclusively during the chronic phase. Optical coherence tomography (OCT) can effectively monitor the loss of retinal ganglion cells. The findings of the study demonstrated that there was a concurrence between histological analysis and retinal ganglion cell layer thinning, thus providing a sensitive method for detecting neurodegeneration in MS. The integration of longitudinal OCT monitoring has the potential to enhance the existing diagnostic capabilities of MRI and neuro performance assessments in tracking the progression of the disease over time. To develop treatments for early-stage MS, it is imperative to gain a comprehensive understanding of the temporal sequence of neurodegeneration. The utilization of OCT monitoring and MRI imaging has the potential to enhance the evaluation of neuroprotective strategy testing [56].

Figure 22. Retinal Imaging.

References

56. Neurodegeneration in multiple sclerosis: retinal imaging as a biomarker. Available from: https://www.openaccessgovernment.org/article/neurodegeneration-in-multiple-sclerosis-retinal-imaging-as-a-biomarker/145548/.

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