In conjunction with WORLD SIGHT DAY on the October 10, Ipoh Echo talks to Consultant Ophthalmologist Dr S.S. GILL on ways to prevent visual impairment.
Visual impairment is a term used to describe any kind of vision loss to the extent that even with conventional forms of correction or treatment, the person’s vision remains poor.
The World Health Organization lists the following facts:
- About 285 million people are visually impaired worldwide:
- 39 million are blind and
- 246 million have low vision (severe or moderate visual impairment)
- preventable causes are as high as 80% of the total global visual impairment burden
- About 90% of the world’s visually impaired people live in developing countries
- Globally, uncorrected refractive errors are the main cause of visual impairment
- Cataracts are the leading cause of blindness
- 65% of visually impaired, and 82% of blind people are over 50 years of age, although this age group comprises only 20% of the world population
What Causes Visual Impairment?
Many factors can cause visual impairment. Cataracts, or the clouding of the eye’s lens preventing light from passing through to the retina, are common causes for loss of vision. Because cataracts form slowly, causing gradual vision loss, it may not be noticeable to the patient. Cataracts usually affect people in their 60s and 70s, but may sometimes appear earlier in people who are excessively exposed to sunlight.
Many patients who present early are golfers and sports people who are not in the habit of wearing sunglasses. The general rule is that you should always wear good sunglasses whenever you go out during daylight hours. Symptoms of cataract include double vision, cloudy or blurry vision, difficulty seeing in poorly lit spaces, and when colours seem faded. Replacement of the eye’s cloudy lens with an intraocular lens (IOL) implant through cataract surgery usually restores vision in these cases.
If you have diabetes, you need to be screened regularly for Diabetic Retinopathy, which is a condition where the tiny blood vessels in the retina (back of the eye) are damaged due to diabetes. People with retinopathy may not have any problems seeing at first. But if the condition gets worse, they can become blind. To help prevent retinopathy, people with diabetes should avoid smoking, keep their blood pressure under control, and keep their blood sugar at an even level.
Another common cause is Glaucoma, a condition where an increase in pressure inside the eye impairs vision by damaging the optic nerve. Any damage to the optic nerve is irreversible so it is important to find out if there is any history of glaucoma in your family as the condition is hereditary. Early detection and treatment is crucial or the vision will gradually deteriorate over time to a small tunnel vision, and then blindness can occur.
Most people may also find it surprising to note that injury is one of the commonest cause for vision loss. Examples like getting hit with a hockey ball or a shuttlecock, or children playing with sharp objects, and injuries from car accidents are common factors. These incidences are potentially devastating and a drastic accident can cause blindness.
Macular degeneration is a gradual deterioration of the macula (centre point at the back of the eye), which is the most sensitive region of the retina. The condition leads to progressive loss of central vision (the ability to see fine details directly in front). Excessive exposure to sunlight and smoking can increase the risk for age-related macular degeneration. Symptoms may include increased difficulty reading or watching TV, as vision becomes distorted and straight lines appear wavy or objects look larger or smaller than normal.
In children, amblyopia or “lazy eye” in early childhood can drastically reduce vision in an eye if the weak eye is not corrected. It is important to detect and treat the lazy eye before the age of 7 or 8 years, before the “vision center” in the brain completes development.
For more information, call Gill Eye Specialist Centre at Hospital Fatimah (05-545 5582) or email email@example.com.