Causes and risk factors
An unequal refractive error in both the eyes (anisometropia) gives rise to refractive amblyopia. Since the brain ignores the blurred images from the bad eye, only half the visual system develops normally whereas the other half remains undeveloped.
Clinical presentation
The visual acuity of the child is reduced to a variable extent. The perception of depth is hampered and hence three-dimensional vision is difficult. Their spatial acuity (ability to detect shapes) and contrast sensitivity (detection of contrast between an object and its background) is poor. Their vision is less sensitive to motion and they frequently experience crowding phenomenon. Their stereoscopic ability (3-dimensional vision) is impaired and they are unable to carry out binocular summation (combining the information received from both the eyes).
Investigations
A vision test can easily diagnose refractive amblyopia.
Treatment
If detected early, refractive amblyopia has good scope for improvement. Corrective contact lenses are the preferred mode of treatment; however, corrective glasses may also be used. Refractive surgery can also be considered.
Patching of the good eye helps to improve the vision in the affected eye. A procedure known as penalisation is also recommended, wherein atropine drops are put in the good eye in order to blur its vision. This helps to develop the visual acuity of the other eye.
Complications
Deprivation amblyopia can result in loss of visual acuity up to the extent of blindness.
When to contact a doctor
Contact a doctor if you suspect that you kid is having any visual trouble.
Systems involved
Ophthalmology
Organs involved
Eyes
