By RAJGOPAL NIDAMBOOR

Human beings, to use a lyrical metaphor, have been “short-sighted” since the dawn of civilisation!

Here’s reason why: there is more to short-sightedness than what meets the eye, albeit we do not really know how the caveman could have hunted, grown crops, and survived, with such an “anomaly.”

Agreed, people with a scientific bent of mind would say that logic suggests short-sightedness, or myopia, should have been eliminated through the process of Darwinian evolution.

But, curiously, such a thing hasn’t happened. Myopia still exists. Wittingly. Unwittingly. And, what’s more, we have been unable to control, or even cure, it.

Agreed, again, that spectacles have been in vogue since the 14th century -- and, its more sophisticated cousin, contact lens, since the last century. But, they are, until now, used for correcting visual problems, or weaknesses, not curing them.

Wait a moment. Thanks to a host of advances in technology, we are now being offered a choice of permanent solutions. Their identity: corneal surgery by diamond knife, or laser, and also eye implants.

Eye laser surgery holds great promise, today. And, the race is “hotting” up to developing it as the cheapest and easiest procedure to correcting eye defects.

Not all eye surgeons have taken to the idea with hypnotic intent, though. Some of them even report that surgical standards and proper aftercare are being undermined. They blame this to a “well-orchestrated” drive launched by researchers/scientists, who have a financial interest in the success of any given method -- one, they may, otherwise, not really espouse.

In this case, the laser solution!

The Beginnings

This is how it all began, with what is called as radial keratotomy [RK]. RK was one of the earliest procedures used by man to correct short-sightedness -- through a diamond blade to “score” over the surface of the cornea. As is quite well known to most of us, the cornea provides two-thirds of the eye’s focusing power. Also, as the incisions made by the blade heal, the central aspect of the cornea is flattened. This foray enables the cornea to place distant objects on the retina at the back of the eye -- and, not in front as it happens in short-sightedness.

William Bates was the first to document cases of RK to cure astigmatism, over 100 years ago. His technique, called the Bates’ method, finds expression in his book, “Perfect Eyesight Without Glasses.” Bates performed about six to eight procedures.

It was about 30 years ago that Russian surgeons improved upon the idea and also the procedure. What they perfected was actually a “conveyor belt” technique. This gave them the advantage of performing nearly 200 operations a day. Ever since, over 800,000 RK operations have been performed worldwide.

Despite all the euphoria, RK is bogged by controversy. Apart from now becoming obsolete, it, quite simply, does not suit everyone. It also does not attract eye surgeons who are unwilling to operate on healthy tissue. Additionally, patients undergoing the procedure must not be too young – and, remember, the eyes must be free of disease. The exercise is irreversible, too. This is not all. Each person’s eye/s react/s differently to RK, although the procedure takes very little time. Recovery, or gain, again, is sometimes slow to manifest, and a few patients may also suffer from impaired vision. This is something that may persist for five years, or more.

A Revolution

A revolutionary technique that scores one of ophthalmology’s greatest triumphs is the more recent photorefractive keratotomy [PRK], or laser surgery. It has two variants: one, which uses the ultraviolet “excimer” laser to wear away the surface of the cornea; and, the other, which uses infra-red light to shrink the cornea’s thin outer layer.

As a matter of fact, lasers have been used in eye surgery for a long time. But, this new technique is different. Unlike conventional thermal lasers, the “excimer” does not cut tissues by generating heat. It does not cut at all! The technique uses high-energy “photons” of ultra-violet [UV] light, which are “fired” at the eye. The photons separate the chemical bonds that hold the tissue together. As a result, the molecule-sized “saucer-shaped” layers are just shaved off the surface of the cornea, without frills or fuss, for a clear, or “twenty-twenty,” vision.

The laser “cure” in the therapy is used for just about a few seconds. This may extend up to five minutes, or more, if required. The downside is: the first one of three days may be quite painful. Also, for a completely clear vision to emerge, there may be a time gap of 3-4 months.

Besides, only one eye is “done” at a time, and some surgeons are known to leave a gap of 6-8 months between two operations.

Although not much is known about the long-term effects, ophthalmologists like J M Boramani, MS, an eye-surgeon, reckon that PRK technique often destroys the all-too-important Bowman’s layer -- a sheen which is located just below the corneal surface -- and, also jostles, or heckles, the corneal structure. This is a major concern, yes; but, efforts are on worldwide, notes Boramani, to making the technique safer, and more refined, without compromising on any generic technological parameter/s.

LASIK Effect

Now, the best part. One new technique has now achieved this objective, albeit differently. Labelled as laser-assisted “in situ” keratomileusis [LASIK], this is a surgical procedure intended to reduce a person's dependency on glasses, or contact lens.

LASIK is an unprecedented advance in eye care. It offers people a safe and simple opportunity to see the world clearly, minus the inconvenience and discomfort of scratched or lost contact lens, or the blocked side vision of eyeglasses. The method has other advantages. It does not destroy the Bowman’s layer. It also minimises post-laser haziness and opacities. This is not all. It does the sculpting, with èlan, in both near and far-sightedness, in the stroma, or the deeper layers of the cornea. Gently.

In simple terms, LASIK is a major breakthrough, where a flap of the superficial cornea is reflected upon itself. The corneal flap, thus, reflected back does not need suturing at all. More that that, the procedure, notes Boramani, is safe. He adds: “We are adding new, great ideas to our existing knowledge. So, it is better that we are guided by a sense of cautious optimism, and not get carried away by the sheer enthusiasm of those who are channelling, even promoting, these miracle ‘shots,’ as panacea.” He also observes, “The future for the field is enormous. We have only just seen a very small part of its glorious possibilities.”

Boramani finds a classical paradox, at this point of time vis-à-vis the PRK technique. In his words: “We have, more or less, a major risk -- the unrealistic expectations of patients. As a matter of fact, most patients think that the procedure is suitable for everyone. No, the technique is advisable only for adults, with stabilised ‘refractive’ error, without any corneal, or ocular, surface disease. Each eye has to be meticulously assessed with different equipment before it is subjected to LASIK. With every passing day, newer and safer machines are arriving. If performed with advanced machines, the technique can really work wonders.”

There are several other uses of the new laser therapy. According to Vinay Byadagi, MS, an eye-surgeon, appropriate laser treatment can also be used for glaucoma surgery. It can be used, adds Byadagi, in the treatment of eyelid tumours, conjunctival anomalies and corneal disorders like opacity. Laser, says Byadagi, can be used after cataract surgery, if there is blurring of vision. He has a futuristic perception: laser for cataract surgery itself. That would be, he observes, a blessing -- and, the quickest possible solution to the problem, too.

Hope For Diabetics

Notes Vatsal Parikh, MS, a vitreo-retinal eye-surgeon, who has been using lasers in the treatment of diabetic retinopathy: “One out of 12 persons is diabetic in India.” He adds: “Diabetic retinopathy is usefully treated with laser in the early stages when it is asymptomatic, or when there is visual deterioration. By timely laser treatment, the risk of severe visual loss, which is 50-70 per cent in ‘proliferative’ diabetic retinopathy, can be reduced to five per cent. Additionally, the risk of moderate visual loss due to macular oedema [swelling] can be reduced by 50 per cent with suitable laser therapy.”

Parikh lays great emphasis on timely diagnosis of patients with advanced diabetic eye diseases like tractional retinal detachment, or vitreous haemorrhage [bleeding], where endolaser and vitreous scissors come as great rescue measures.

LASIK, the new laser option, is super-fast. Bloodless. Precise. It is exquisitely, and remarkably accurate. It can remove very minute amounts of corneal material without damaging the surrounding tissue. While it is agreed that after-surgery scars may follow in one in 10,000 patients, the saving grace is that scarring or even infection can be corrected with a different laser procedure. What’s more comforting is -- there’s absolutely no evidence that exposure to laser therapy causes cancer and/or even cataracts.

Laser therapy is quite expensive, ranging between Rs 8,000 [US$200] and Rs 30,000 [US$600], or more, depending upon a host of parameters: from the reputation, expertise of the eye-surgeon, the hospital, and so on.

But, costs are bound to come down in the future. Until then, glasses would be in vogue. And, they will continue to be so in the future -- too. Like the good, old newspaper, which has survived the advent of high-tech electronic jazz, or advance, but with improved aesthetics.