What are different types of refractive surgeries?

by Niraj Jayaswal Content Writer

Summary:

There are various oculoplastic surgery hospitals in India that offer refractive surgeries. Doctors hailing from refractive laser surgery hospitals in Delhi along with oculoplastic surgery doctors in Delhi have good expertise in the area Dr. Subhash M. Betharia is one of the trusted names when it comes to ophthalmic plastic surgery in Delhi.

Article:

Refractive surgeries, as the name suggests, are used to treat various different types of refractive eye defects which can otherwise hinder your normal vision. The main goal of a refractive surgery is to reduce or to an extent, end the need for glasses or lenses. There are no major procedures to be followed during refractive surgeries as these are mostly invasive.

A good vision is usually defined in terms of the extent of adaptability of the lens and cornea to focus light on the retina. The retina is a light-sensitive layer present at the back of the eye. It functions to transfer the light energy, adapted into the rods and cones, through the optic nerve to the brain where it is interpreted to generate the images of the objects they are coming from. Refractive errors arise in the cornea which is not shaped properly. Cornea being the clear part in front of the eye bends at different angles to transmit the incoming light. Due to a present refractive error, the light waves often do not focus on the retina leading to the formation of a blurred image. All in all, there are four major types of refractive errors:

Myopia (Nearsightedness):

The objects which are placed close to the eyes are only visible clearly while distant objects appear blurred. This happens due to the lengthening of the eye by the highly curved cornea. Thus, the image formation takes place in front of the retina rather than on it.

Hyperopia (Farsightedness):

In this case, distant objects are seen clearly whereas objects placed nearby are not clearly visible and appear blurred. This happens due to the flattening of the cornea. In this, the image is formed behind the cornea.

Astigmatism:

In this case, the image formed is blurred both when the object is kept close to the eyes as well as placed far from it. Here, the lens and cornea are shaped so that image is formed on the retina.

Presbyopia:

This is common in older people and often known as ageing eyes. The focus of the eyes is lost due to the natural ageing process. Surgeries cannot correct this problem, but it might make distant vision clearer. It should, however, be kept in mind that the surgery can make your near vision worse.

Types of refractive surgeries:

LASIK:

This treatment is done to correct myopia, astigmatism and hyperopia. The treatment procedure involves reshaping of the cornea through laser surgery, it is a very famous procedure which has replaced many other. It is done using a computer controlled cold excimer laser. With a tool the surgeon cuts a thin layer form the centre of the cornea to flattens it, then the layer is reattached without stitching it. It only takes a few minutes.

Photorefractive keratectomy (PRK):

It is done with a similar kind of laser as used in LASIK. PRK works for issues in nearsightedness. The surgery takes a few minutes to be done and after that one to two weeks to be completely healed.

Radial Keratotomy (RA):

In this procedure, tiny cuts called incisions are made in the cornea using a diamond scalpel. The process is used to correct nearsightedness. During the surgery, a small cut Is made in the cornea in order to flatten it, thus leading to lesser refraction. Just like other procedures, it takes a few weeks to heal.

Astigmatic keratotomy (AK):

This surgical procedure is used for extreme cases of myopia and hyperopia. In case of myopia, a cut is made in the outer layer of the cornea using microkeratome to make it flat by removing a layer of the cornea, whereas for hyperopia a deeper cut is made to make a flap. The deeper cut creates a pressure in the eyes leading to the bulging out of the corneal surface thus improving the optical power. After this, the flap is put in surface again and it attaches itself.

Laser thermal keratoplasty (LTK):

In this case heat from the laser is used to reshape the cornea by shrinking the collagen fibres present in it.

Conductive keratoplasty (CK):

it is used to correct mild to moderate level of hyperopia. It uses low-level radio waves to shrink the collagen fibre and change cornea’s shape. A device smaller than the thickness of the hair is used to put radio waves around the cornea which creates a tight band around it leading to an increase in the curve.