26/05/2020
Let's talk Cataracts today
Definition: It is an opacification of the eye lens, usually due to age-related pigment build-up. It leads to ↓transparency and ↓refractive index of lens, and hence visual impairment.
Causes of premature cataracts:
1. Steroids, including topical therapy near eyes.
2. Congenital: trisomy, myotonic dystrophy, infection (rubella, HSV).
3. Ocular disease: glaucoma, severe myopia, retinal detachment.
4. Dabetes
5. UV or infrared radiation.
Epidemiologgy
Cataracts are etremely common: 30% prevalence over age 65, and 60% over 80.
Signs and symptoms
Symptoms:
✓ Blurred vision and gradual ↓acuity, with difficulty reading, watching TV, and recognising faces.
✓ Glare from bright lights.
✓ Monocular diplopia.
✓ Loss of stereopsis if unilateral.
Signs:
- Reduced red reflex.
- Clouded lens.
Investigations
Clinical diagnosis. Can be supported by slit lamp with dilated pupil, but not obligatory.
Management
Non-surgical
Conservative treatment is often appropriate initially, as cataracts has a highly varied rate of progression, with significant impairment often taking many years to develop.
Advise not to drive and to contact the DVLA if there is difficulty reading a number plate from 20 metres.
Surgical
Indications:
When symptoms restrict lifestyle including driving, reading etc.
Procedure:
Phacoemulsification: lens broken up with ultrasound and aspirated from the eye. It is an extracapsular extraction i.e. lens removed but lens capsule left in place.
Intraocular lens implant inserted into remaining capsule.
Done under local anaesthetic in around 20 minutes.
Complications:
Perioperative: haemorrhage, local anaesthetic-related, vitreous loss.
Early post-op: endophthalmitis, anisometria, eye or eyelid bruising.
Late post-op (months later): posterior capsular opacification causing blurred vision (common), retinal detachment.
Outcome:
Improves visual acuity, though reading glasses usually needed afterwards.
Find us at Kakamega Eye Clinic for more eye health education services.
