Dr Leonard Ang
Medical Director
Senior Consultant Ophthalmologist
Lang Eye Centre
Millions of people around the world go blind from eye disease every year. Of the 5 senses, sight is probably the most important sense. Sight is so important yet, many people take it for granted until it is lost. Many common blinding conditions occur after the age of 40. A simple eye examination with an eye specialist would be able to detect these conditions so that they may be treated. However, many people neglect to visit an ophthalmologist for routine eye checks as they get older.
Common age-related eye conditions that are the leading causes of blindness in the world are cataract, glaucoma, age-related macular degeneration and diabetic retinopathy. In most situations, blindness can be prevented if the condition is detected and treated early. Please see below for common age-related eye conditions:
Cataract
Cataract is the most common cause of blindness in the world. In Singapore, 35% of the population above the age of 45, and 80% of the population above the age of 60 suffer from some degree of cataracts.
A cataract is a condition where the clear lens of the eye becomes cloudy, which reduces the amount of light entering the eye. The most common symptom of cataracts is a gradual, progressive blurring of vision.
Cataract surgery is required if the cataract is impairing vision and affecting one’s daily activities. A common misconception is that one should continue to wait for cataracts to continue to ‘ripen’ or for the vision to be significantly affected before doing surgery. In fact, when cataracts are too ‘ripe’ or severe, there is a greater risk of developing other eye diseases such as glaucoma, and the surgical risk also increases when removing a more dense cataract.
With modern cataract surgery, it is not necessary to wait for cataracts to be dense or the vision to be poor before performing surgery. Modern cataract surgery in the form of phacoemulsification can now be performed safely and effectively and takes less than 20 minutes per eye. The wound being about 2mm in length, improves safety and speed of recovery. An artificial intraocular lens is implanted immediately following the cataract removal.
Modern advances in cataract surgery aim to help individuals achieve better vision and spectacle freedom. Bladeless cataract surgery, computer-assisted imaging systems, and better machines aim to make surgery more precise, efficient and safer. These days, there are intraocular lenses that are able to provide sharper vision and correct all forms of refractive errors (such as short-sightedness, astigmatism and presbyopia), so that individuals can reduce or eliminate the need to wear spectacles after surgery.
Glaucoma
Glaucoma is the leading cause of irreversible blindness in the world. It results from an increase in eye pressure which causes progressive damage to the optic nerve. Glaucoma accounts for about 40% of registered blindness in Singapore. About 5 out of every 100 Singaporeans suffer from glaucoma, many of whom do not even realise that they have the disease.
It is usually a slow progressive disease that affects middle-aged and elderly people. In the early stages, there are no obvious visual symptoms, which is why glaucoma has been called the ‘Silent Thief of Sight’. The vision loss arising from glaucoma begins in the periphery and slowly progresses towards the centre when it is very advanced. That is why those with glaucoma are usually not aware that they have this condition until a late stage. Glaucoma causes permanent irreversible damage to the optic nerve and irreversible vision loss.
Glaucoma may be treated with eyedrop medication, laser treatment or surgery. Modern medication is very safe and effective and most people are managed with eyedrops alone. Laser treatment may be required in certain types of glaucoma, especially the angle closure type of glaucoma.
Surgery is usually considered for those with glaucoma that is not well-controlled despite the use of multiple eyedrops. Minimally Invasive Glaucoma Surgery (MIGS) utilises minimally invasive surgical techniques and modern minute devices or implants that can allow people to recover faster from surgery than traditional surgery.
Those with glaucoma require regular follow-up to monitor progression. The examination involves assessing the eye pressure, visual fields and optic nerve evaluation to check for optic nerve thinning. Ultimately, early detection and treatment of glaucoma is important in preventing blindness. Considering the prevalence and seriousness of glaucoma, it is therefore imperative to go for regular eye screening.
Diabetic retinopathy
Diabetes affects about 12% of the adult population in Singapore. People with diabetes may develop eye complications such as diabetic retinopathy or cataract which may cause severe vision loss or blindness. As many as one-third of diabetics, especially those who have had the condition for more than 10 years, will develop complication of the eyes. About 10% to 15% of these are serious and sight-threatening.
The high sugar level in diabetics results in diabetic retinopathy, which refers to damage to the inner nerve layer of the eye (retina) and the retinal blood vessels as a result of diabetes. Abnormal blood vessels may grow over the retina and nerve, which can leak fluid and bleed.
There are usually no symptoms in the early stages of diabetic retinopathy. The vision may not be affected until the disease is more severe. An eye examination is often the only way to diagnose this condition. That is why regular eye examinations is recommended for those suffering from diabetes.
When there is significant diabetic retinopathy, an out-patient laser treatment may be required to slow down the progression and prevent vision loss. Laser treatment can help to reduce swelling of the retina by targeting the abnormal leaky vessels, as well as reduce the risk of formation of abnormal new vessels that could bleed easily and cause sudden vision loss.
Leakage of fluid and swelling of the retina may require injections of medication into the eye to help to reduce abnormal vessel growth and reduce fluid leakage. Surgery is usually the last resort for more advanced cases where there is bleeding into the eye, scar tissue formation and retinal detachment.
At the same time, it is important to control blood sugar level, blood pressure and cholesterol level. This could help to prevent the rate of progression of the disease.
Conclusion
About 80% of blindness is preventable if the eye disease is detected and treated early. Early detection and treatment of cataract, glaucoma, AMD, diabetic retinopathy and other eye diseases is the key to preventing blindness. Because many of the common blinding conditions start off with minimal symptoms and gradually cause vision loss, many do not realise they have eye disease till it is more severe.
Eye disease treatment is considered safer and more effective now. Modern treatments not only prevent vision loss, but can improve one’s vision and quality of life. As such, do not wait for the eyes to be severely affected before seeking treatment.
It is therefore advisable to undergo a detailed eye examination with an eye specialist for those above 45 years old. The eye examination can help to detect and diagnose potentially blinding eye diseases in the early stage, so that treatment can be started early. Regular eye screening is therefore important to prevent vision loss.
