Eye Disease
While ocular health problems can occur at any age, the most common conditions are those associated with aging. If not identified and monitored early, serious vision impairment can occur.
Cataracts
A cataract is a condition where the lens within the eye becomes cloudy and opaque. Cataracts vary from extremely small areas of cloudiness to large areas that cause a noticeable loss of vision. They occur occasionally among young people, but are more frequent in people over the age of 55.
Cataracts may develop quickly, but usually form gradually over a period of several months or years. They often develop more rapidly in one eye than the other. Some indications that a cataract may be forming include: objects appearing to be yellowed, haziness resulting in blurred, distorted or even double vision, an increasing need for more light, and night glare causing you to see haloes or rings around bright lights.
During your eye examination, your optometrist will analyze the opacity of your lens and tell you whether or not you have a cataract. During the first stages of development, a change in the lens of your glasses may improve vision to a satisfactory level. If vision cannot be improved sufficiently and the cataract is interfering with your work or other activities, then cataract surgery is considered. This procedure is performed by an ophthalmologist (eye surgeon) after consultation and evaluation of your ocular status.
Cataract surgery involves removal of the crystalline lens and implanting a new intra-ocular lens. Usually the surgery requires only a local anaesthetic, and takes 30 minutes or less. Healing and recovery can take up to eight weeks, at which time vision should be moderately stable. Generally there is need to refine vision with glasses or contact lenses after the eye has stabilized. Cataract surgery is thought to be about 90% successful in restoring functional vision, and this is improving continuously with advances in technology. If you suspect that you may have cataracts, see your optometrist for an assessment. In most cases the distortion and visual discomfort of cataracts are easy to treat.
Glaucoma
Glaucoma is a disease of the eye which is characterized by increased pressure within the eye itself. Fluid continually moves in and out of the eye and if the drainage mechanism becomes blocked, the pressure within will rise. The same thing occurs when too much fluid is produced and the eye is unable to cope with the drainage.
When the pressure inside the eye is high, the tissue and blood vessels become stressed and may become unable to function properly, resulting in damage to the nerve filberts. When the optic nerve has been damaged, there is typically a loss in peripheral vision. There is no set pressure at which damage occurs, and in some cases the pressure within the eye may be very low, even subnormal, and yet too high for the tissue to function properly.
Glaucoma usually affects both eyes, but may affect only one. It is dangerous because in most cases it occurs without any pain and may not be noticed until a significant amount of damage has occurred. Vision loss typically occurs over a number of years but, in cases of acute glaucoma, sight can deteriorate dramatically in just a few hours.
Glaucoma most frequently occurs in people over the age of 40 and also tends to be hereditary, so those with a family history of the condition should be monitored closely. Diabetes, vascular disorders and some medications may also put you at higher risk. Routine optometric examinations for people identified at risk for glaucoma include a test to measure the pressures of your eyes (tonometry) and an internal inspection of the optic nerve. Your optometrist may also recommend a visual field test to determine if there has been any loss in peripheral vision.
If your optometrist diagnoses glaucoma, you will be referred to an ophthalmologist, who will determine the appropriate treatment to reduce the pressure within the eye. Typically, treatment begins with the use of drops. Various methods of surgical reduction in pressure are becoming more popular as techniques are being developed and perfected. After the pressure has been lowered with treatment, the eyes are monitored for further losses in peripheral vision so that treatment can be adjusted as necessary.
Glaucoma is a major cause of blindness in Canada. However, the sooner it is diagnosed and treated, the better the prognosis. Periodic examinations are critical, especially if there is a family history of the disease.
Macular Degeneration
People are often unaware of this condition at first, because macular degeneration initially may affect only one eye -- and the "good" eye tends to compensate for the affected eye. And, although your central vision may become poor, your peripheral vision almost always remains intact, provided that there is no other coincidental disorder.
Although lost vision due to macular degeneration cannot be recovered, early diagnosis is important, as some cases may be treated by laser surgery to delay progression of the condition. Your optometrist routinely checks the condition of the retina during your eye examination and will refer you to an ophthalmologist if you are a candidate for laser surgery.
Your optometrist may also advise changes in lifestyle as well as nutritional supplements that have been shown to delay progression of macular degeneration that is not treatable by laser surgery. If your vision loss cannot be treated, special low vision aids, magnifiers and telescopes may be recommended to assist your vision function. You may also be referred to the Canadian National Institute for the Blind, which operates vision enhancement clinics in Winnipeg and Brandon.
Other Retinal Disorders
Your optometrist is also able to detect other conditions of retinal damage, including tears, detachment or degeneration caused by hypertension, diabetes or artery problems. These disorders can be severe and lead to partial or total vision loss if not diagnosed and treated early.
If a problem is discerned, you will be referred to your family physician or an eye surgeon for examination and treatment.
Ocular Conditions Associated With Systemic Disease
Ocular or vision problems can also be caused by or symptomatic of diseases that are not specific to the eye. Diabetes, hypertension, multiple sclerosis - even brain tumours - are examples of systemic disease that can manifest symptoms, sometimes serious, in the eye. If your optometrist suspects your vision problems are related to other health concerns, you will be referred to your family physician or the appropriate specialist for a full medical assessment.
