Over the last 20 years, causes of blindness have changed both in proportion and actual numbers; however, cataract has still remained the major cause of blindness and refractive error 1)Vijaya L, George R, Asokan R, Velumuri L, Ramesh SV. Prevalence and causes of low vision and blindness in an urban population: The Chennai Glaucoma Study. Indian J Ophthalmol 2014;62:477-81 was the main reason for low vision globally and more so in Asia 2)Jose R, Rathore A S, Sachdeva S. Community ophthalmology: Revisited. Indian J Community Med [serial online] 2010 [cited 2018 Apr 29];35:356-8. Available from: http://www.ijcm.org.in/text.asp?2010/35/2/356/66893.
Most common diseases like,
2. Macular Degeneration
3. Diabetic Retinopathy
4. Retinitis Pigmentosa
5. Corneal Blindness
As we age, our lens becomes gradually opaque resulting in light rays blocked off from the retina. This condition is called cataract. Cataract is a normal ageing process. About half of those over the age of 60 will have some degree of cataract and hardly noticeable for many among them.
People with uncontrolled diabetes can develop diabetic retinopathy. Diabetes causes weakening of the blood vessels in the body. The tiny, delicate retinal blood vessels are particularly susceptible. This weakening of retinal blood vessels, accompanied by structural changes in the retina, is termed as diabetic retinopathy.
Retinitis Pigmentosa is hereditary with dominant, recessive and X-linked fashion which can also appear in any age. It is a degenerative disease which primarily involves retina. Symptoms are night blindness, reduced peripheral vision (‘tunnel’ vision) and ultimately decreased central vision.
AMD – Age-Related Macular Degeneration – is a common eye disease like cataract and glaucoma. It is the leading cause of severe vision loss in people aged 50 or more. In susceptible people, their macula, a delicate region in the retina, gets gradually damaged.
Causes and Consequences:
Four aspects are clearly related, causes on the left side of the diagram and consequence on the right. We already know that generally, diseases occur as a structural/ functional change at the organ level. The only way to treat is through medicines and surgery. If the damage of the disease is larger then it inadvertently affects the skill and ability to do day-to-day activities (functional vision loss). In that case, we provide and help with visual aids to improve their functional loss. If the visual impairment is very severe, psychologically it affects their social and economic status. For this, we have low vision rehabilitation centres, we train and educate the people how to live their life.
References [ + ]
|1.||↑||Vijaya L, George R, Asokan R, Velumuri L, Ramesh SV. Prevalence and causes of low vision and blindness in an urban population: The Chennai Glaucoma Study. Indian J Ophthalmol 2014;62:477-81|
|2.||↑||Jose R, Rathore A S, Sachdeva S. Community ophthalmology: Revisited. Indian J Community Med [serial online] 2010 [cited 2018 Apr 29];35:356-8. Available from: http://www.ijcm.org.in/text.asp?2010/35/2/356/66893|