The steps of the procedure in brief are as under:

Local eye drops are given four or six times. The person is fully conscious and needs no systemic or general anesthesia; in fact, the patient and the surgeon may be talking to each other. The procedure is painless.

The person lies on a table and the top of the table has a mounted microscope connected to a laser machine. The machine is automatically controlled by a computerized data machine. The machine has all the data of the person’s corneal thickness, error of refraction, I.e. power of the spectacle glasses to be corrected, laser depth and all the precise parameters in full to ablate the layers of the cornea.

Let us elaborate here the recent advancements in the techniques that have evolved.

Laser (PRK) is an old technique where the corneal surface is hit by laser directly and the laser is called exciter laser’ which is a unique laser beam different from others.

In the recent technique a thin corneal flap is cut by a keretome and lifted up baring the inner surface where the exciter laser beam is hit to make the centre of cornea thin to the required depth. The higher the power of myopia the greater is the corneal depth hit by the laser. This technique is termed as Lasik. It is now in vogue all over the world and in some centers of our country. It has many advantages, e.g. quick recovery, no aftereffects of glare and blurring, and full vision in few days.

There is another improved technique over the Lasik, called wave-front Lasik that hits all the points of the cornea mapped out by an aerometer. It is a marvel of modem laser technology of ophthalmic sciences. If the operation is successfully performed the person achieves above normal sight without glasses.

It suffices to state that all the procedures are fully automated by the laser surgeon who is trained and has the expertise from national and international centers. He should have performed about 500 laser procedures under the care of a master laser specialist.

The laser machine with its accessories, is expensive and costs around 3-4 cores. It is insured for maintenance by high-tech engineers of electronics and software at heavy costs. It is an outdoor procedure and does not need hospitalization. It takes ten minutes to perform the operation.

Lasik is more technically perfect than other forms of refractive surgery. It is safe and successful all over the world.

The post Lasik recovery period is about three-four days and the patient gets back to routine in seven days, the patient does not experience any pain.

Following are the prerequisite criteria for a person to be fit for Lasik?

Age 19 to 21 years is most essential for laser in myopic eyes. At this age the increase in the power of minus number stabilizes. When the height of a person stops increasing, i.e. at the age of 19-21 the myopia stops increasing.

Lasik is never performed and contraindicated in an increasing state of myopia.

Eye components must be normal, healthy and free from any diseases, e.g. glaucoma, corneal scars, retinal and vitreous diseases and cataract.

The ideal range for Lasik procedure on myopia is -3 to -15. However, the specialist decides the criteria. Lasik in plus numbered glasses hypermetropia and glasses with astigmatism compound can also be performed on +3 to + 10 in persons who wear high plus glasses. They are a minority group unlike myopias.

1. Getting rid of spectacle glasses or contact lenses. There is a slogan ‘Sight without glasses by laser’ coined by laser experts of modem times.
2. Retinopathy of diabetes that affects the retina of a diabetic person.
3. After cataract surgery.
4. Glaucoma.
5. Diseases of retina and vitreous.

Getting Rid of Spectacle Glasses by Laser

In recent times, as early as last decade, this subject has evolved to a path-breaking precision allover the world. So much so that experts now can predict 100 per cent results horn laser in getting rid of spectacle power in the following conditions where thick glasses are worn.

Myopia (Short-sightedness)

Short-sighted eyes have a minus power which may vary from as low as -0.5 to as high as -20.Laser is most commonly used for myopia between -2.5 D to 7.5 in ideal situation. The surgeon is the final authority. The average and common range is between -1.5 to -6. Less common range is -6 to -10 and least common is -10 to -20. But the common features of myopia are that they all progress with age and height (see chapter on Myopia) and one has to wear cumbersome and thick glasses.

(a) Cataract (lens sclerosis) (-15%).

(b) Lazy eye or squint correction with myopia of birth (amblyopia) (-10%).

(c) Detachment of retina (-12%).

(d) Vitreous hemorrhaged and floaters.

The incidence of these complications is not more than 20 per cent. Hence, the apprehensions of a mope person are based on flimsy grounds. About 80 per cent myopic carry on with their routine like anyone else.

Detachment of Retina and Vitreous Hemorrhage

These maladies find a solution with surgery under a very careful and planned regime in a retinal clinic. It is of utmost importance that surgery for retinal detachment in a high myopic be undertaken by a specialist of vitreous and retina. The modem treatments for retinal and vitreous problems are cryosurgery and laser therapy (photocoagulation) (see also the chapter on ‘Diseases of Retina and Vitreous’). Procedures on retina and vitreous are a super specialty under a surgeon trained for these only.

Squint and Lazy Eyes

Lazy eyes since birth and myopia with a squint need to be examined and treated in a special ‘orthoptic clinic’. Here the lazy eye is carefully assessed and attempts are made to restore vision by- exercises and visual stimulation (see also the chapter on ‘Squint or Cross-eye’).

Correction of Myopia by Laser/Lasik

The accepted therapy for myopia is by laser which is discussed in the next chapter. Besides myopia it can treat other refractive errors, e.g. astigmatism and hypermetropia.

1. When there is disparity of spectacle power correction between the two eyes, i.e. if the difference of power between the two eyes exceeds -3, ordinary spectacle glasses cannot work. If they are worn the wearer sees double (diplopic).

Contact lenses are the only way to deal with problem of diploid.

2. When cataract is removed from one eye and the other eye is quite normal (one-sided cataract removal).

3. Very high myopia with astigmatism of irregular kind (conical cornea).

It goes a step further in providing natural visual field and, above all, stops the myopia from increasing at an alarming rate. The last factor is singularly the most favorable point in contact lenses.

It is easy to understand that the placement of the lens on the surface of the cornea brings a film of tears between the lens and the cornea. This film of tear fluid, which has the same refractive index as the cornea, neutralizes any irregularity in the curvature of the cornea. The contact lens of a myopic has a minus number power ground into it from the spectacle power prescription given by the eye specialist. However, in practice, high-powered myopic with high astigmatism benefit additionally by the contact lenses.

There are two types of basic contact lenses-hard and soft contact lenses.

Hard Contact Lenses

A hard lens is made of highly inert and refined plastic material which rests on the cornea. It has no water and oxygen content and the nutrition to the cornea is supplied by the tear film and atmospheric air in and around the lens. These lenses cannot be worn for long stretches and certainly not during sleep. They rest lightly on the cornea due to surface tension. They move with lid movements. A clear area must be there between the cornea and the surrounding white sclera for free tear flow. There is a tendency for them to slip off if not properly fitted. This is perhaps their disadvantage. They correct even high astigmatism and are economical in cost. The hard contact lenses now do not find favors with eye specialists. They have been replaced by semi soft, comfortable and gas permeable lenses.

Soft and Semi-soft Contact Lenses

The soft lenses have a high water and oxygen content. They are very light, thin and collapsible, like a section of a balloon. They rest more comfortably and tightly on the cornea and the surrounding sclera and can be worn for a greater length of time. They do-not slip off or move with the lids. Their high water and oxygen content is a great advantage. They have a tendency to wear off if not carefully handled. They are delicate and require expert handling and sterilizations. Also they are more expensive. The semi-soft (gas permeable) contact lens have now replaced· the hard lenses for wearing in astigmatism. They are comfortable and have a long life.

Most of us do know what a balanced diet is in theory but few put it into practice. Calcium and Vitamin D must be given as extra elements to all children with myopia. The ideal forms of Calcium and Vitamin Dare milk products, green vegetables, fish and eggs.

A balanced diet will not stop myopia from increasing but it will certainly slow down the rate of increase.

Why does myopia increase? What can the doctor do? What can the parents and patients do? Will regular wearing of spectacles arrest myopia? Will wearing glasses increase myopia? Will wearing glasses become a habit and therefore should be avoided? These are some questions asked by parents of myopic children and the answers to them are as follows:

1. There exists the erroneous notion that by wearing glasses the power of myopia does not increase. Some also feel that they can get rid of their glasses by wearing them regularly! Both ideas are incorrect. By wearing glasses regularly eye strain is minimized, but the eye length is anatomical and independent of this.

2. The increase in myopia is a natural process where the length of the eyeball increases. It is like increase in height and in length of hairs and nails. And there is nothing one can do to stop it. It takes a natural course. This natural} course has the following two forms:

Simple Myopia: In simple myopia, the spectacle power begins to set in by the age of 10-12 years and rises very gradually by 0.5. At puberty or adolescence, when the child gains height, the power jumps by -I, -2, or even more. This is the period when the parents may get alarmed. The process is natural and hereditary in 75 per cent of myopias.

The increase continues till the age of 20 to 25 and then stops on its own. The power rarely rises above -6 or -7. At the age of 35-40 it begins to come down by -0.5 or -1 and then stabilizes. If this person gets a cataract it may further reduce, depending on the type of cataract. At times it disappears altogether during old age and the person is blessed with a second sight without glasses. Ninety-five per cent of simple myopia improves with glasses.

High Myopia: The term high myopia is used to indicate myopia which sets in during early childhood, i.e. one or two years of age, and progresses very rapidly during adolescence. It touches high scales, -6, -7, -9, by 14 years of age. Its further progress is slow and steady till the age of 30 when it may reach marks as high as -10 or -20. Cases touching -15 or -20 are a small percentage but do occur. There are rare cases where even a power of -26 in both eyes may need to be prescribed.

In short, high myopia has inherent tendency to progress-beginning in early childhood and going up rapidly to the highest peak by the age of twenty. The two classes just described are scientifically accepted entities. The latter group needs constant care and observation from the specialist.

Myopia can manifest itself at a very early age, even in a newborn. The first examination becomes necessary at the age of two years if the mother is in doubt about her child’s eyesight. But, in practice, we have found that a child whose parents are myopic must be examined in the clinic just before entering primary school (KG). As a matter of routine-all pre-school children should have their eyes examined. It is not difficult to obtain the cooperation of a child for a quick and careful examination for any spectacle power. Further detailed examinations of the eyes may need special tests. A small child between two and five years of age will wear glasses for school if he or she has myopia of -2 or more. There is no ground for being apprehensive or fearful. An average child who sees better with glasses will look after them and wear them gladly. But, of crucial importance is that he or she must see better with them. Small children who do not take to wearing glasses despite two or three attempts must not be forced to do so. They should wait till the age of five or six for another detailed examination. Ninety-five per cent of children will see better with glasses and benefit from them. Experience in clinic tells us that parents escorting children need full assurance, counseling and sympathy. A mother easily gets upset when her child is prescribed spectacles.