Every experience, idea, and memory relies more on sight. To see is to believe – defines the true potential and role that eyes play in our lives today. A tiny speck can blur our vision, cause irritation, and warrant immediate attention. Healthy eyes are prerequisite for all our basic chores; and with the increasing amount of ‘screen staring’ – corrective lenses are becoming a norm. Myopia, Hypermetropia, Presbyopia and Astigmatism are the regular issues we battle constantly now. Although they are among the most common eye-related disorders, they are being passed on from one generation to another as a ‘gift.’ In Asia, genetics and parental pressure on reading are both claimed to have adverse effects on children’s eyes. However, Indians specifically resist eye checkups and lenses. Hubert Sagnieres, Chairman and CEO of Essilor, the world’s largest maker of ophthalmic lenses mentioned that India loses $37 billion dollars on account of poor vision – there are 550 million Indians that require vision correction but are not making any active effort for the same (Times of India, May 31, 2013).
While some can be corrected with lenses, there are many that are not so simple. Let us consider some of them:
Retinitis Pigmentosa (RP) is a group of genetic disorders that affect the retina’s ability to respond to light. Various forms of RP include Usher syndrome, Leber’s congenital amaurosis, rod-cone disease, Bardet-Biedl syndrome and Refsum disease. This inherited disease causes a slow loss of vision, beginning with decreased night vision and loss of peripheral (side) vision. It is a progressive disorder, typically diagnosed in adolescents and young adults. The rate of progression and degree of visual loss varies from person to person; however, the disease eventually results in blindness, as there is no cure for it.
Since the first reported mutation associated with RP in humans by Dryja et al., 1990, 26 genes for autosomal recessive (AR) RP and 20 for autosomal dominant (AD) RP, and 2 genes for the X-linked RP have been identified until 2010. Sen et al., 2008, has estimated presence of RP as approximately 1 in 930 of urban while 1 in 372 of rural general South Indian population, aged 40 years or above. These stats demand our attention to the growing prevalence of this disease.
Age-related Macular Degeneration
Age-related Macular Degeneration (AMD) is a common eye condition and a leading cause of vision loss among people aged 50 and older. It causes damage to the macula, a small spot near the center of the retina and the part of the eye needed for sharp, central vision. AMD by itself does not lead to complete blindness. However, the loss of central vision can interfere with several activities, such as the ability to see faces, driving, reading, and writing. Risk factors include old age, smoking, race, and family history. Since 2005, several genetic variants have been consistently associated with AMD. The common coding variant Y402H in the complement factor H (CFH) gene was the first one to be identified. Several other genetic loci have also been shown to affect AMD risk. These include other variants in CFH, and genes: factor B (BF)/ complement component 2 (C2), complement component 3 (C3), and complement factor I (CFI). Another disease with no permanent cure makes it crucial for to be aware of its onset and slow down its progression.
Glaucoma is a condition that causes damage to eye’s optic nerve, often associated with high intraocular pressure. If this damage continues, due to high eye pressure, it will cause permanent blindness in a few years. There are two kinds of the disease: open-angle glaucoma (most common) and angle-closure glaucoma (less common in western countries). Risk factors include age, race, poor vision, and diabetes. Again, being incurable and hereditary, one has to be cautious and regular with eye checkups. Although the disease cannot be cured, the pressure can be controlled with early detection and periodic medication.
Diabetic Retinopathy (DR)
Diabetic Retinopathy (DR) and RP are referred as opposite poles of genomic medicine – one is a single gene disorder and the other possesses a multifactorial etiology. Diabetic patients are a host to several eye conditions – DR affects blood vessels in the light-sensitive tissue called the retina that lines the back of the eye. It is the most common cause of vision loss among people suffering from Diabetes. Diabetic macular edema (DME), a consequence of diabetic retinopathy, is swelling in an area of the retina called the macula. Other conditions include cataract and glaucoma.
• Cataract is a clouding of the eye’s lens. Adults with diabetes are 2-5 times more likely to develop cataract.
• Glaucoma – In adults, diabetes nearly doubles the risk of glaucoma.
All forms of this diabetic eye disease have the potential to cause severe vision loss and blindness in people.
With most of these diseases being incurable, one must rely on more than sight now. We must choose what to see and what to avoid – we cannot afford to be blind to the existence of these disorders. Although, most are genetic, lifestyle is a huge criterion for all as well. Diabetes for instance can most definitely be detected early or prevented. Similarly, regular eye checkups for people with a family history of such diseases are a necessity. We must be aware and do our bit to enjoy the luxury and wealth of ‘good health’ – I See, You See, We all See – A Healthy Me!
Mapmygenome can help you protect your eyes
Mapmygenome offers many different services to protect your eyes:
- Genomepatri: Genomepatri tells your genetic predispostion to AMD and Glaucoma as well as 100 other conditions. Understand your genetic risks to fight conditions related to eyes and causal factors such as type 2 diabetes better.
- Diagnostic tests: We have a range of diagnostic tests related to conditions mentioned above.
- Genetic Counselling: Worried about an inherited condition in the family? Our genetic counsellors can help you by analyzing your health history.
To learn more, call 1800-102-4595 or write to firstname.lastname@example.org.
About the author
Dr. Pallavi Jain is part of the Scientific Team at Mapmygenome. She has a Bachelors Degree in Biochemistry with Genetics and a PhD in Molecular Medicine (UK). She recently completed an intensive course in IVF from Origio, Mumbai. She enjoys swimming and reading.