Multifocal lens: A new advance

Wouldn’t you like to have a full range of vision, from near to far, following cataract surgery? Not many people facing this operation would say “no thanks”. But until a few years ago, multifocal vision was merely a dream. Now it’s a reality and thousands of patients are benefiting from the new AMO Array mutifocal lens – many of whom won’t even require glasses after undergoing the operation to have the lens installed.

Cataracts are opacities in the eye lens caused by aging, disease and heredity. If your father and grandfather suffered from them, chances are you will, too. Early symptoms are inconspicuous: colours may appear a bit dull, with less contrast; and later, patients will notice increased glare, and night driving becomes difficult. Other risk factors: Diabetics have four times the chance of developing opacities in the lens; patients suffering from hypothyroidism and glaucoma have a higher than usual incidence of cataracts; and exposure to radiation, high electric voltage and lightning can also trigger the condition.

Evidence suggests cataracts are caused by oxidation of lens protein. During our body’s normal metabolic process, oxidation produces what are known as “fr radicals”, highly reactive molecules that damage the cells in the lens, just as oxidation causes steel to rust and butter to become rancid.

There’s no way to prevent cataracts. However, we do know the eye needs large amounts of vitamin C, as the cornea and lens have the highest concentrations of this vitamin in the body.

Professor Paul Jacques of the Human Nutrition Research Centre of Aging at Tufts University studied the blood levels of vitamin C in cataract and non-cataract patients. He found patients with low blood levels of vitamin C were 11 times more likely to develop cataracts.

Dr. James Robertson of the University of Western Ontario compared the vitamin intake of cataract patients and those without over a five-year period. His findings? Those who took vitamin E supplements reduced their risk of cataracts by 50 to 70 per cent. Vitamins C and E are powerful antioxidants and help “mop up”, deactivate, destroy or prevent free radicals from forming.

Dr. Roger F. Steinert, Assistant Professor at The Harvard Medical School, heads a team of doctors evaluating multifocal lenses.

In the trial, 400 patients chose one of three options: a multifocal lens in both eyes, the conventional monofocal lens in each eye, or a combination – namely, a multifocal lens in one eye and a monofocal lens in the other eye. The study’s conclusion? There was both a physical and psychological benefit using the multifocal lens in both eyes.

Dr. Stephen Koknen, a noted German ophthalmologist, carried out a similar study. He recently told ophthalmologists meeting in Frankfurt that patients who had the multifocal lens implanted had better uncorrected near vision than those given the monofocal lens. Dr. Koknen stated, “there is no doubt in my mind that perhaps 30 to 50 per cent of patients who undergo cataract surgery would benefit from the multifocal intraocular lens.”

However, the AMO Array multifocal lens isn’t for everyone. For example, due to possible glare problems, it might not be suited for patients involved in considerable night driving, or for architects and others who do a lot of close-up reading. But for many other cataract patients, the multifocal lens is another important step towards normal vision.