Cataract is the opacification or clouding of the crystalline lens. It is the commonest cause of blindness and low vision in the world.
- Congenital e.g. Rubella, Toxoplasmosis.
- Developmental: Senile occurs with ageing
- Secondary e.g. Traumatic, Diabetic,
- Drug induced, post uveitic etc.
- Gradual, painless loss of vision
- In the early stages, it feels like looking through frosted glass.
- If secondary, symptoms and signs of
causative disease are also present.
- Leukocoria (White pupillary reflex)
- Corneal opacity
- Other causes of leucocoria e.g. Retinoblastoma (in children), retinal detachment, severe ocular toxoplasmosis etc.
- In congenital cases, it can lead to amblyopia (lazy eye) if not operated early
- Intumescent cataract with secondary glaucoma
- Phacolytic uveitis and glaucoma
- Pupillary light reflex
- Macular function test
- Projection of light
- Ocular ultrasounds scan: especially in cases of trauma to exclude pathology of the posterior segment of the eye
Treatment objective –
- To remove the cataractous lens
- Replace with a clear plastic lens inserted into the eye (except in infants).
- An extracapsular cataract extraction with posterior chamber intraocular lens implant (ECCE + IOL) is the most appropriate for older children and adults.
- Small incision cataract surgery and
phacoemulsification are recent advances of the ECCE technique.
- In new born babies and infants, a
lensectomy and anterior vitrectomy is the preferred surgical procedure.
- Aphakic glasses or contact lenses are worn to correct the resulting refractive error.
- Posterior capsular opacity following ECCE could be treated with surgical or Yag laser capsulotomy.
Caution and contraindications to treatment
- Intraocular lens implants is not advisable for new born babies and infants.
- Aspirin and other aspirin like analgesics have been found to delay cataracts in patients with diabetes and rheumatoid arthritis.
- Antioxidant vitamins – Vitamin C has been found to have a protective effect against nuclear and posterior subcapsular cataracts.
- Vitamin E has also been found to protect against nuclear and cortical cataract.