APHAKIA

absence of lens in eye 

CORRECTION

spectacles

Aphakia is treated by prescribing suitable spherical convex lens (+ 10 D approximately) and convex

cylindrical lens (+1 to +2D at 180°) 6 weeks after the operation, i.e. when the corneo-scleral scar

has healed completely and the refraction has become stable.

problems with aphakic correction

1. They are heavy and give a cosmetically poor appearance.

2. There is 25% retinal image magnification hence it causes diplopia in unilateral aphakia.

3. Spherical aberration can cause ‘pin-cushion’ effect. There may be chromatic aberration. This leads to visual distortion.

4. There is ‘jack in the box’ ring scotoma and reduction in peripheral visual field.

5.  Physical invonvenience and cosmetic deficiency are usually present.

2. Contact Lens

Advantage

There is minimum retinal image magnification therefore it is specially useful in case of unilateral aphakia. It also looks good cosmetically.

Disadvantages

• Daily cleaning and maintenance is needed

• Their insertion and removal is problematic.

• Corneal epithelial oedema, erosion and vascularization may occur due to hypoxia

• Conjunctivitis, intolerance and foreign body sensation are common complaints.

• Loss, breakage and deterioration of the contact lens leads to financial loss.

3. intraocular lens

rigid

foldable