As Canadians age, they become at risk for a host of health problems, with one of the most common and insidious being loss of vision. One of the leading causes of vision loss in the elderly is Age-Related Macular Degeneration (AMD), which attacks the centre of the retina, where the most important vision cells reside. For sufferers of AMD, particularly wet AMD, new medical developments are providing a wealth of treatment choices that can preserve their vision.
“There are two different types of macular degeneration, dry and wet,” explains Dr. Netan Choudhry, Director of Vitreoretinal Surgery at the Herzig Eye Institute. “In the dry form, people develop small protein deposits in the retina called drusen, which leave pot-holes in the retina that manifest as dark spots in the patient’s vision. The wet form, which can arise from the dry form, is a little bit different. In this form, abnormal blood vessels begin to grow like a weed from the deep tissue in the retina. These vessels bleed, causing fluid accumulation under the retina, which damages he vision cells if left untreated.
Though wet AMD is less common than dry AMD (comprising 10-15 percent of total cases), it has a more dramatic prognosis, resulting in complete central vision loss if untreated. “In the old days wet AMD was devastating; everybody lost central vision,” says Dr. Alan Berger of St. Michael’s Hospital. “Prior to about 2005, with the treatments we had available at the time, only one to two percent of patients say any visual improvement while 90 percent went downhill. With the advent of the anti-VEGF drug injections, we now have 90 percent seeing stability of vision or improvement.”
Today, there are two Health Canada approved anti-VEGF ( Vascular Endothelial Growth Factor ) drugs on the market for wet AMD and other retinal diseases. Both are known to be safe and effective. However, it is important for physicians to be able to choose the best treatment for each individual patient. “As we have moved forward, we have developed more options,” says Dr. Choudhry, “in some cases one option may provide the opportunity for a more relaxed injection schedule than another.” Further, some specific subtypes of wet AMD may respond differently to one over another. There’s no one best treatment for everyone at this stage, which is why having access to multiple therapies is so important to physicians and patients.
The good news is wet AMD is now almost entirely manageable with early intervention and access to the full range of approved treatments for the one in twenty-five Canadians currently living with this condition, and the many more who will develop it as they age. Canadians can look forward to a bright and clear old age with minimally invasive care – so long as this freedom of choice remains available and new innovative treatments continue to develop
D.F. McCourt
Macleans magazine, May 30 2016
