Caffeine and Eye Health: Exploring the Double-Edged Sword of Caffeine on Eye Health.

Rohan Mandal, D. Optom

Fellow Optometrist in Retina and Posterior Segment, Dr. Shroff’s Charity Eye Hospital, New Delhi, India

 

Introduction:

Caffeine is a widely consumed stimulant found in coffee, tea, and various energy drinks. Nowadays, caffeine has become an integral part of many people’s daily routines. Its effects on productivity and discreteness are well known. The effect of caffeine on Eye health is a topic that deserves attention. Let us explore the good and bad aspects of caffeine consumption pertaining to Eye health.

Good aspects:

• Improved Alertness and Focus: Caffeine works as an instant stimulant. Therefore, it increases the brain’s activity and the flow of nerve impulses in the Central Nervous System (CNS).
  Hormones like cortisol and adrenaline help to reduce stress and have an effect on increasing heart rate, and blood pressure as well as improving vision. Caffeine increases the circulation of cortisol and adrenaline. ^(1-3)
• Reduced Dry Eye: According to various studies caffeine increases the function of tear secretion in the eyes. It was reported that people who take coffee a minimum of 2 to 3 times a day have a lower prevalence of dry eye. ^(4,5)
• Protection Against ARMD and Diabetic Retinopathy:  Studies suggested that caffeine helps in inhibiting the choroidal and retinal cell migration, i.e., the Retinal Pigment Epithelial (RPE) cells of retina. The adverse effect of this RPE cell migration is very well documented in diseases like ARMD. Therefore, this effect of caffeine is reported as a protective function against ARMD. ⁽⁶⁾ For disease like diabetic retinopathy it is reported in the literature that people who consumed caffeine 2 to 3 times a day have a reduced risk (~65 %) of progression of diabetic retinopathy. ⁽⁷⁾
• Protects Against Cataract Formation: Literature suggests that caffeine influences increasing antioxidant and bioenergetic effects on the lens. An increase in caffeine use may reduce the chance of developing cataracts. ⁽⁸⁾

Concerned Aspects:

• Increased IOP and Chances of Glaucoma:  Many researchers and ophthalmologists have suggested the patients with glaucoma to avoid excess consumption of caffeine. According to literature, consuming a cup of coffee increases the chance to raise IOP by 1 mm/hg within an hour. ^(9-10)
• Disruption of Sleep:  Adenosine is a nucleoside which is produced by all cells of our body. It is a sleep-promoting receptor found in our brain. Caffeine blocks the action of adenosine, and this in turn disrupts the sleep cycle. ⁽¹¹⁾
• Occlusion and Damage Retina:  Hormone prostaglandin is a vasodilating agent, i.e., it works in dilation of vessels. In various studies, results suggest that caffeine blocks the function of prostaglandin. Some researchers believe that caffeine causes our adrenal glands to produce more adrenaline hormones. Therefore, this effect on prostaglandin hormone and adrenaline hormone increases the chance of raised blood flow within the body as well as in the eye. Further, this can lead to occlusion in the retina of our eye. ⁽¹²⁾

Navigating the balance:

In a nutshell, the important aspect is that we must maintain a balanced consumption, which can maintain normal function and keep our eyes healthy.

• Know your limit – Understand the tolerance of caffeine by your body and maintain a moderate consumption that suits your daily routine.
• Mindful timing – Avoid caffeine before going to sleep as well as maintain the gap between consumption and bedtime of at least 5-6 hours.

Conclusion:

In the realm of eye health, caffeine plays a dual nature – a protector and a potential adversary. By embracing moderation and mindfulness, we can leverage the benefits of caffeine for our eye health while minimising the risks.

 

References:

1. https://www.betterhealth.vic.gov.au/health/healthyliving/caffeine [Last accessed 26^th March 10:00pm]
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4. Jeong, K. J., Choi, J. G., Park, E. J., Kim, H. E., Yoo, S. M., & Park, S. G. (2018). Relationship between Dry Eye Syndrome and Frequency of Coffee Consumption in Korean Adults: Korea National Health and Nutrition Examination Survey V, 2010-2012. Korean journal of family medicine, 39(5), 290–294.
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10. https://www.insightvisionoc.com/optometry-2/how-much-is-too-much-caffeine-for-glaucoma-patients/ [Last accessed on 25^th March 9pm]
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