INTRODUCTION
Keratoconus is one of the leading causes of blindness. Generally, it begins in adolescence and progresses until the patient is aged 30-40 years when its usually arrests (Rabinowitz, 1998). Keratoconus is a relatively common condition and mainly leads to corneal grafting. Despite a number of researches the exact pathological mechanism of Keratoconus progression is unknown, although it is widely accepted that oxidative stress plays a critical role in its development and progression (Chwa, 2008).
WHAT IS KERATOCONUS?
It is a non-inflammatory eye condition in which the normally round ‘dome-shaped’ cornea gradually thins and causes a ‘cone-shaped’ bulge structure. Affected individuals develop a blurry vision, sensitivity to light also known as photophobia, and additional vision problems like poor focusing ability which in turn causes poor vision.
PREVALENCE
The exact reason is unknown, but it is believed that genetics and environmental factors play a role in the same. Mainly it is seen in teenagers or in the early ’40s. The condition worsens in people with certain medical problems including certain allergic conditions. It could be related to chronic eye rubbing.
In various surveys, it has observed that it is mainly found in north India especially in Jammu-Kashmir or Ladakh region.
CAUSES
Tiny fibres of protein in the eye called collagen helps to hold the cornea in place and keep it from bulging. When these fibres weaken, they are unable to hold the shape leading to a cone shaped cornea. Keratoconus is caused by decreasing protective antioxidant level in the cornea. The cornea cells protect the eye from getting damaged by external chemical products like smoke, etc. Antioxidants reduce the oxidative damage and protect the collagen fibres. Thus, if antioxidant levels are low, the collagen weakens and the cornea bulges out.
SIGNS AND SYMPTOMS
Keratoconus progression can be divided into 2 stages: Early Stage and Later Stage.
HOW TO DEAL WITH KERATOCONUS
Keratoconus is a noninflammatory degenerative disease. In the initial phase, eye tries to adapt with the new corneal shape and are able to fix the vision with the cost of a headache. As the days pass if untreated the severity of the condition progresses and may cause permanent vision loss. In the initial phase, frequent changes in visual acuity (eyesight number) has been seen. To identify the severity ‘Corneal Topography’ test is performed, which can be done from any proper eye centre or hospitals. If keratoconus is detected in eyes, then the size of the cornea has to be measured and customised lenses can be made to prevent further deterioration of eyes. Keratoconus cornea is thinner than a normal cornea. Diet doesn’t have a direct role to play in the disease as it is a non-inflammatory degenerative disease. But as the cornea gets damaged due to a low antioxidant level, it is believed that regular diet high in antioxidant like carotenoids can help to reduce the progression of this disease. Currently randomised control clinical trials are going on in the University of Miami, phase 1 has been completed, whereas phase 2 is under-process, but the overall result is yet to come.
In vitro studies have shown that an increase in metabolites is related to oxidative stress in Keratoconus disease, and the corneal cells undergo oxidative stress and tissue damage. Animal studies have shown a therapeutic effect of Vitamin C (ascorbate) in corneal wound healing. Glutathione and Vitamins A, C, and E are also important antioxidants in the human body. Thus, diet rich in vitamin A, C, E and glutathione might help to pause the degeneration of eyes.
CONCLUSION
Keratoconus is a progressive eye disease in which the normal young cornea thins down and produces a cone-like shape. The cone shaped cornea deflects the light entering the eye on its way to the light-sensitive retina causing distorted vision. Keratoconus can occur in both eyes and often begins at teenage or in early ’40s. Symptoms of Keratoconus is the blurring of vision which can’t be corrected with glasses. Most people affected with Keratoconus initially develop near sightlessness, it worsens over a period of time. In the initial phase contact lenses are a part of the main treatment. Severe stages may require corneal transplantation. A new treatment called Corneal cross-linking is in its experimental phase. In this treatment cornea become hard and stops the further progression of the disease, then cornea is reshaped through laser treatment. Keratoconus is a common disease but each individual needs a different treatment and care.
REFERENCE:
- Rabinowitz, Y.S.(1998).Keratoconus. Surv Ophthalmol. 42(4),297–319
- Chwa, M., Atilano, S.R., Hertzog, D. et al. (2008).Hypersensitive response to oxidative stress in Keratoconus corneal fibroblasts.Investigative ophthalmology & visual science. 49. 4361-4369
- The Role of Antioxidant Supplementation in Keratoconus Patients. (2019). Retrieved from https://clinicaltrials.gov/
