October 06 2009
The tests involved in my latest eye check-up might have come from a futuristic gaming arcade; they certainly seem a long way from those at my local optician – squinting at a wall chart, a brief examination of each eye with a bright light and a puff of air to the eyeball to check for glaucoma. At the London Vision Clinic I’m faced by five machines to peer through. The first shows a set of whirling spirals that spin down to a red patch that pulses like something from a space odyssey. The next, a “Wasca” (Wavefront Aberration Supported Camera Ablation), is like looking down the sight of an advanced sniper rifle with lots of crisscross lines; a third faces me with a small frosted window pane and a glowing red light behind it that suddenly flips and twists.
After 20 minutes, printouts provide unprecedented detail on the topography of my cornea, imperfections in my vision far more subtle than the two normally checked for – short sight and astigmatism (misshapen lens or cornea) – and a measure of intraocular pressure (related to glaucoma). One machine measures the thickness of my cornea to one micron (a human hair is about 100 microns across). And there is still another 20 minutes to come.
An increasing number of private optometry centres, such as the London Vision Clinic, now offer tests and services that go way beyond anything you’re likely to get at your local optician. The difference mirrors that between getting your teeth done privately or on the NHS. But while everyone knows that NHS dentistry only provides the basics, many still believe that a regular eye test can tell you all you need to know. “An NHS eye test is the equivalent of going into your dentist’s surgery, flashing a smile and walking out again,” says Professor Dan Reinstein, founder and medical director of the London Vision Clinic. “There’s a lot more to an eye test than seeing if you need new lenses and checking for diseases such as glaucoma and cataracts. It can give information about your cardiovascular system and your brain.”
Of course, Reinstein has a vested interest, but a 2007 study by consumer magazine Which? found that 17 out of 39 high-street opticians weren’t doing the basics – and even gave patients the wrong glasses or failed to spot signs of serious health problems.
Bruce Evans, director of research at the Institute of Optometry, explains, “The problem, as usual, is money. We get paid about £20 to carry out a test on the NHS. That’s not enough to fund the test adequately and the low fee invariably has to be subsidised by profits from the sale of spectacles.”
Following recent changes in the regulations governing eye tests in Scotland and Wales, England currently has the most cursory in the UK. “Because the NHS sight test system in England has not moved forward in line with developments in equipment and professional practice, many optometrists wish to improve their ability to detect eye diseases by using methods not included in the basic test. Some opticians are therefore offering more advanced tests,” says Evans.
If you want the best, most comprehensive eye care, Evans suggests that a digital picture of the retina, which can be stored and checked for changes that may point to disease in the future, is important. Some branches of Specsavers offer this but, inevitably, it’s no longer cutting-edge technology. The latest refinement of the retinal camera is known as 3D OCT (Optical Coherence Tomography); it takes a 3-D picture so that optometrists can see what is going on inside the retina, allowing problems to be spotted much earlier.
The MacuScope is a major improvement in the detection and treatment of AMD (Advanced Macular Degeneration), a leading cause of blindness. It occurs when pigment in the macula at the centre of the retina starts to break down. “The MacuScope doesn’t just allow us to spot who is likely to have a problem,” says David Crystal, an independent optometrist whose practice, Eyecare Plus in Edinburgh, was one of the first to bring it into the UK. “There is now evidence that atrophy of macular pigment can be improved with a supplement, and the MacuScope can check the progress of treatment.”
The Visual Field Analyser is another useful device that shows up in some NHS practices (though not the latest version). It’s useful for spotting if peripheral vision is deteriorating, which can be a sign of problems such as a retina that is beginning to detach. More sophisticated tests like these allow contact lenses and spectacles to be fitted more accurately but also make it much more likely that health problems will be picked up.
“The eye is a window on the body,” says Reinstein. “A proper examination of the eye can show up problems with lungs and kidneys, and the retina can provide clues to cardiovascular problems, such as high blood pressure and strokes. Abnormalities in the tear film can tell you about diet and whether you’re deficient in omega-3 oils.”
Unfortunately, while the technology at some private optometry clinics is highly sophisticated, methods for finding them are not. There is no central list and the professional organisations don’t offer help. So it’s down to old-fashioned word of mouth and trial and error. Before making an appointment, ask exactly what is involved. A good examination normally lasts 35 to 40 minutes and involves a fairly comprehensive questionnaire about your general health with tests using some of the latest equipment.