While in poetic terms the eyes may be windows to the soul, in medical terms they are unique windows to health.
When eye specialists look into the back of an eye they see a microcosm of the person’s health. Not only do they see diseases that exist but they see evidence of diseases that are developing and have not yet declared themselves. One ophthalmologist recently found himself looking into the eyes of a man complaining of erratic vision. The man, a computer engineer in his early 50s, said his vision in one eye kept moving in and out of focus. It would be fine for a few minutes, become fuzzy for a few minutes and then become fine again.
At the back of his troubled eye the specialist saw a little lump of fatty material. It was the same material that usually accumulates on the walls of the large arteries in people with arterial disease. The lump had been swept off the carotid artery in his neck, travelled through his blood supply and lodged at the back of his eye.
Before he referred him to a vascular specialist, the ophthalmologist told the man how lucky he was. Had a bigger piece swept off and lodged itself in his brain, he could have had a stroke.
This man, who was at the peak of his career, presented with an eye problem but was spared a stroke that would have taken him out of the workforce and might even have killed him.
Nowhere else in the body are blood vessels so finely displayed as they are on the retina. It is like a showcase. Because of this, ophthalmologists regularly detect problems the patient is unaware of.
Among the conditions most commonly detected are high blood pressure, diabetes, hardening of the arteries, high cholesterol and various forms of inflammatory disease such as arthritis.
Despite the importance of vision and the value of having a medical eye examination, more than 50 per cent of Australian adults have never visited an ophthalmologist. Look at the case of a woman in her 30s who complained that when she read, the words slipped sideways. They were so mobile she couldn’t fuse them into the sentence.
When tested with the chart, her vision came in perfectly at 20/20. It was a different matter when her peripheral vision was tested. She had lost half the peripheral vision in each eye.
The symptoms were classic: she had a pituitary tumour in her brain that was compressing her optic nerves. Following surgery to remove the tumour, her previously excellent vision returned.
While the eyes provide windows to the rest of the body, they also contain within themselves signs of their own destruction. Ophthalmologists can see the beginnings of disease processes that will disable the eyes perhaps 30 years later. In many cases, these can be prevented or inhibited.
Most eye problems in Australia are associated with ageing.
The older people get, the more likely they are to have major conditions such as glaucoma, macular degeneration or cataracts.
The progression of the eye disease glaucoma illustrates the importance of prevention. It causes a build-up of excessive pressure in the eye, and by the time the person realises there is a problem, 90 per cent of the optic nerve is dead and the person is close to being blind. But doctors can pick it up easily, even in the very early stages, and provide eye drops to stop it.
Early detection can also inhibit macular degeneration, the leading cause of legal blindness in Australia. This condition results in the loss of central vision, but evidence that this loss will occur is apparent decades before the disease takes its toll. Smoking is a major risk factor for this condition, as is exposure to the sun’s ultraviolet (UV) rays. In some people laser surgery can help to inhibit macular degeneration.
Most people have surgery in their 70s for cataracts that began developing in their 40s. Again, smoking and UV exposure are risk factors. But so is diabetes. Eye specialists regularly pick up cases of undiagnosed late-onset diabetes when they come across patients with cataracts.
The fierce Australian sun is particularly effective in ravaging eyes. Over time, its high-energy UV rays can discolour the white of an eye, turning it an unattractive shade of yellow.
Its rays can also cause the formation of pterygium – unsightly masses of tissue that grow like clouds over the white of the eye and can obstruct vision. When sunlight damages the fine skin around the eye and causes a skin cancer, removing it can be a major job.
Skin cancers elsewhere in the body can usually be removed without causing much damage to the surrounding tissue. But around the eyes there is little in reserve. Removing a cancer from an eyelid without disturbing the function of the lid is difficult. The simplest way to protect eyes from the ravages of the sun is to wear dark glasses.
The one thing that can’t be protected against is floaters. By their late 30s people have begun to notice small dark spots or cobweb-like fragments appearing in their vision. These are called floaters and are fragments wobbling and moving in the gel inside the eye. They are caused by condensation of the gel.
When people look at the bright sky, the floaters appear as dark spots. When they suddenly turn their heads, floaters lag a bit behind but eventually appear in their field of vision almost like a piece of dust or a hair on a camera lens. Floaters are only a worry if they suddenly proliferate or are accompanied by (lashing lights. This could mean the gel is separating from the retina and emergency intervention may be needed. If you see flashing lights, you must get help.
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