Causative & risk factors
Myopia is a refractive eye disease wherein the eye structure becomes too elongated from front to back. Hence the light rays cannot reach the retina thus making distant vision blurry. These eye changes are believed to be caused due to a combination of genetic and environmental factors.
Pathological myopia is usually hereditary. Females are more commonly affected. Certain races like Chinese, Japanese and Jews are more prone. Pathological myopia is usually associated with several other conditions such as Marfan’s syndrome, Down’s syndrome, glaucoma and retinopathy in newborns.
Clinical presentation
Myopic changes usually begin in childhood or adolescence. However it can begin even in younger children as well as older adults.
The chief symptom of myopia is impairment of distant vision. Objects at a distance may appear blurred or unclear. One is unable to read classroom blackboards or road signs. The central vision may be lost especially in cases of pathological myopia.
The patient may experience eyestrain. The visual field may contain flashes of light or black floaters and adapting to a dark environment may become difficult.
The patient may develop a divergent squint (exophoria). The eyeball, cornea and pupil may become enlarged.
Progressive myopia can give rise to complications like retinal tear or detachment, vitreous hemorrhage or degeneration, cataract, glaucoma and blindness.
Investigations
A simple eye test is adequate to make a diagnosis of myopia. The patient is made to read out letters of varying sizes from a chart. A myopic person will be unable to read certain letters depending upon the degree of myopia. The same test is now carried out in a computerized form (retinoscopy) wherein the machine automatically detects the degree of near-sightedness.
Treatment
The commonest treatment is prescription of corrective spectacles or contact lenses.
Some people may opt for laser surgery to correct the eye defect. In patients with severe myopia, an artificial lens can be implanted into the eye.
Recent updates
A recent study has shown that the more number of years one spends getting educated/attending school, the higher are the chances for developing myopia.
A new oral medication known as 7MX is being tested to reduce the progression of myopia in children.
