Gradual Visual Loss

Question 1

Define a cataract? How would it appear on opthalmoscopy?

Answer 1

Cataracts are lens opacifications. Cloudy spots on the lens.

Question 2

Classify the different forms of cataracts?

Answer 2

They can be classified on cause or location.

Location: Cortical or Nuclear (Think m&m cortex is sugary coating)

Causes:

Age related (by far most common)

Traumatic (trauma, blunt trauma, InfaRed, Radiation, Electric shock)

Metabolic (diabetes mellitus, Wilson’s + others)

Iatrogenic (steroids, chloropromazine, chemo, thalidomide) S

econdary to other conditions (Uveitis)

Maternal Infection during gestation (Rubella, CMV, Toxoplasmosis)

Question 3

Briefly describe how a cataract operation is done?

Answer 3

An incision approximately 3 mm in diameter is made in the sclera.

A round hole of approximately 5 mm diameter is made in the lens capsule.

The hard lens nucleus is liquefied by an ultrasonic probe inserted through the hole, and extracted.

Soft lens fibres are aspirated.

The replacement lens (which can be used to correct any refractive errors) is placed folded into the now empty capsular bag where it unfolds.

The hole heals without sutures.