ON THE An inside look at a vital aspect of eye health.
We all know our eyes are important. But, did you know that the retina, the thin layer of tissue that lines the back of the eye, is perhaps the most critical part of our eye? Not only does it receive light and convert it into neural signals that are sent to the brain for visual recognition, but it also plays a part in everything from myopia ( near- sightedness), diabetes, hypertension and high cholesterol to macular degeneration, glaucoma and cataracts.
Made up of 10 complex layers, our retina houses millions of photoreceptors, which are the most vital cells in our visual pathway, explains DR CLAUDINE PANG, Consultant Eye Surgeon and Medical Director at Asia Eye Surgery Centre.
“If we were to compare our eyes to a camera, the retina is the film with which all images are collected,” she says. “When our cornea or lens is diseased, we’re able to replace it with corneal transplant or fix it with cataract surgery, respectively. We have no such replacement for the retina. Therefore, it’s important to protect and prevent disease in our retina from a young age, since our retina health determines our visual health for life.”
One of the most common retinal diseases, says Dr Pang, is retinal detachment, a condition that occurs when the retina becomes loose and is pulled away from its normal position. Though not painful, it’s considered a medical emergency and requires immediate treatment. “While medical science has paved the way for today’s treatments, any delay in treatment may still lead to severe vision loss or even blindness,” says Dr Pang.
Early signs of retinal problems include blurring of central vision and wavy lines in the central vision. In the case of peripheral retinal diseases like retinal detachment, seeing floaters (spots that appear in your vision) and flashes of light may be an early sign, explains Dr Pang. “Late signs would be a dark shadow or curtain developing over part of our visual field.”
Even if you’re experiencing few symptoms, it’s important to go for eye check-ups, says Dr Pang. “Retinal holes and tears, for example, occur at the periphery of our retina, so there may be no symptoms whatsoever. If untreated, they could lead to sight-threatening retinal detachment, which requires immediate surgical repair. Those with high myopia are at particularly higher risk of such retinal tears and holes.”
Glaucoma – also known as the “silent thief of sight” – is another example with few or no symptoms in its early stages, as it affects peripheral vision first. “As most people do little to test their peripheral vision, they tend not to realise when it’s compromised,” says Dr Pang. “In addition, there are no symptoms for elevated eye pressure, an early sign of glaucoma. Therefore, it’s essential to get your eyes screened, especially for those with a family member with glaucoma, as it’s hereditary.”
Dr Pang believes adults above 40 should have an eye check- up once a year if their last eye exam was normal; once every six months if a cataract, glaucoma or other retinal disease has been diagnosed.
“During an eye exam, we check for cataracts, glaucoma, retinal diseases including macular degeneration and retinal tears or holes,” she says. “We can also pick up early signs of hypertension, high cholesterol, diabetes and anaemia just from looking at the retina. At the same time, we also check for dry eyes, blepharitis ( infection of the eyelids), contact lens problems, corneal infections and computer vision syndrome. We’re also able to address myopia prevention, treatment of floaters and correction of presbyopia (loss of accommodation).”