Why do I require a retina examination before Lasik?
Lasik is a procedure to change the refractive status of the eye using laser energy and help one achieve perfect vision without the need for spectacles. Constant use of spectacles may not be desirable for a person for a number reasons – independence from glasses, cosmetic appearance, heavy spectacles in people with high myopic/hypermetropic refractive error, restricted field of vision due to the spectacle frame.
The retina is a layer of nervous tissue which lines the eyeball on the inside and is responsible for the final vision of the eye. Hence, a healthy retina is crucial for a perfect vision. However, it is not uncommon for the retina to have some inherent areas of weakness, such as lattices, holes and tears. These areas of weakness may be seen in normal eyes, but eyes with myopia are found to be more predisposed to these lesions.
The eye of a myopic person is larger in size than that of a normal eye. In order to adapt to this bigger eye, the retinal layer in slightly stretched out and hence, is prone to develop areas of weakness. It is very important to identify these areas of weakness in all eyes undergoing Lasik surgery, as any procedure on the eye may transmit unavoidable forces to these weak areas, which can result in extension of the lesion and if unnoticed, rarely retinal detachment.
The procedure for retinal examination requires dilatation of the eyes using mydriatic drops, followed by examination of the retina using a light source and hand held lens. Due to the effect of the mydriatic drops, the vision of the patient is temporarily blurred. This effect, however, wears off in 3-4 hours.
Retinal examination includes:
Assesment of the vitrous gel that fill the eyeball for any opacities or degeneration.
Assessment of the health of the optic nerve.
Assessment of the central retina (macula), which is responsible for our central vision and ability to read.
Assessment of the peripheral retina for any lattices, breaks or holes in the retina.