Inside the eye, there is a clear structure called the lens that focuses images on the retina. The lens is continuously growing and thickening since birth. With age, the lens becomes cloudy, and slowly causes blurry vision that is not correctable with glasses. In the early stages of cataracts, vision may not be affected at all. Our doctors, however, can detect early formation. When the cataracts start to affect daily activities, surgery can be done to replace the natural lens with an artificial implanted lens. Often times, an individual’s prescription is put into the implant providing functional uncorrected distance vision. Factors that can contribute to the formation of cataracts include ultraviolet rays, traumatic injury, systemic condition like diabetes, or specific medications like steroids.
Diabetic retinopathy is the leading cause of blindness in the working population in Canada. It is a result of damaged blood vessels in the retina, which leads to the leakages, formation of new weaker vessels (neovascularization), and other changes. If left untreated, diabetic retinopathy can result in blindness. It is very important for diabetic patients to work with their family doctor and/or endocrinologist to control their blood sugar levels, and have annual eye examinations with their optometrists to monitor their ocular health. Our doctors can identify any vision threatening signs and initiate appropriate treatment to prevent irreversible vision damage.
Glaucoma is the degeneration of the optic nerve that leads to a loss of peripheral vision, then later central vision. The most common type of glaucoma is Open Angle glaucoma, which can progress asymptomatically and painlessly, while the less common type of Acute Angle Closure Glaucoma can cause nausea, vomiting, eye pain, and blurry vision. The optic nerve is responsible for transmitting information from the eye to the brain. If the optic nerve degenerates, information cannot travel to the brain, resulting in vision loss. Our brain, however, is very good at masking visual field defects; hence, early stages of glaucoma can develop unknowingly to an individual. The only way to detect glaucoma early on is through a comprehensive eye exam, where our doctors evaluate the health of the optic nerve. When necessary, a visual field test or other technology may be used to determine one’s risk. It often takes about 40-50% of nerve fibre loss before visual defects are even perceived. The risk is also higher for individuals who have a positive family history of glaucoma. Currently there is no cure for glaucoma. However, the deterioration of vision can be slowed down with medicated eye drops or surgery. Regular eye examinations with your optometrist can help screen for and prevent glaucoma.
Macula is the central vision area that provides the best vision to see small details and colour. With age, similar to other parts of our body, the macula can deteriorate, leading to decreased visual acuity and distortion. This is known as Age-Related Macular Degeneration (AMD or ARMD). If severe, it is possible to lead to central blindness; the periphery, however, can remain unaffected. Unfortunately, there’s currently no cure for AMD, but there are ocular vitamins that can be taken or eye injections by specialists in the moderate to severe stages to slow down the progression. There are 2 forms of macular degeneration: dry AMD and wet AMD. Dry AMD is the more common of the two forms, and has a better prognosis. However, dry AMD can become wet AMD, where there is a leakage of fluid or blood. Vision in dry AMD deteriorates slowly over time, while wet AMD can be detrimental. It is important to take preventative measures, such as UV protection and a healthy diet, at a young age to protect the macula. Additionally, the risk of macular degeneration in patients increases with a positive family history of AMD and in previous or current smokers. Regular eye examination can help screen for early onset of AMD and our optometrists can discuss various methods of maintenance and prevention of macular degeneration.
Source: Doctor of Optometry