Glaucoma screening is imperative. In glaucoma, the optic nerve at the back of the eye is slowly destroyed. The incidence of glaucoma in the general population over 40 is about 2% (1 in 50) but this risk increases to about 20% (1 in 5) if an immediate family member has glaucoma. This may be due to increased pressure inside the eye or caused by poor blood supply to the optic nerve at the back of the eye, a weakness in the structure of the nerve, or a problem in the health of the nerve fibres themselves.
A comprehensive eye test is more than just an eye pressure check but at Vision Excellence, this is still one of the tests that needs to be done in glaucoma screening. Strictly speaking, high pressures alone do not constitute the disease of glaucoma. It is possible that intraocular pressure (IOP) is higher than normal without ever losing vision and although relatively rare it is also possible to have normal eye pressures and still get the disease, a condition known as “normal-pressure” or “low-tension” glaucoma. Rarer still is another type called “angle-closure” or “closed-angle” glaucoma which involves a spike in eye pressure due to the shutdown of drainage in the eye which can cause devastating and permanent loss of vision if not treated immediately.
Recent research has revealed many subtle changes that occur in the eye as early warning signs of the disease, including corneal thickness and microscopic changes to specific parts of the retina that are invisible to traditional views of the back of the eye. For this reason, we have equipped our Vision Excellence practice at Norwest with OCT instrumentation that allows us to capture corneal thickness and images of these specific parts of the retina and the drainage angle of the eye, to measure them for immediate assessment of the risk of glaucoma and to securely store images and data for future comparison, allowing us to detect any subtle changes in the years to come. Obviously, we also have visual field testing facilities to identify and quantify more advanced glaucomatous changes.
Whether or not there is a family history, all adults should undergo glaucoma screening at least every two years. Our optometrist will advise you if you are at higher risk and whether you need to be checked more regularly.