The following is a classification of the various types of cataracts. This is not comprehensive and other unusual types may be noted.
- Classified by etiology
- Age-related cataract
- Immature Senile Cataract (IMSC) - partially opaque lens, disc view hazy
- Mature Senile Cataract (MSC) - Completely opaque lens, no disc view
- Hypermature Senile Cataract (HMSC) - Liquefied cortical matter: Morgagnian Cataract
- Congenital cataract
- Sutural cataract
- Lamellar cataract
- Zonular cataract
- Total cataract
- Secondary cataract
- Drug-induced cataract (e.g. Corticosteroids)
- Traumatic cataract
- Blunt trauma (capsule usually intact)
- Penetrating trauma (capsular rupture & leakage of lens material - calls for an emergency surgery for extraction of lens and leaked material to minimize further damage)
- Classified by location of opacity within lens structure (However, mixed morphology is quite commonly seen, e.g. PSC with nuclear changes & cortical spokes of cataract)
- Anterior cortical cataract
- Anterior polar cataract
- Anterior subcapsular cataract
- Nuclear cataract - Grading correlates with hardness & difficulty of surgical removal
- 1 - Grey
- 2 - Yellow
- 3 - Amber
- 4 - Brown/Black (Note: "Black cataract" translated in some languages (like Hindi) refers to Glaucoma, not the color of the lens nucleus)
- Posterior cortical cataract
- Posterior polar cataract (importance lies in higher risk of complication - posterior capsular tears during surgery)
- Posterior subcapsular cataract (PSC) (clinically common)
- After-cataract - posterior capsular opacification (PCO) subsequent to a successful extracapsular cataract surgery (usually within 3 months - 2 years) with or without IOL implantation. Requires a quick & painless office procedure with Nd:YAG laser capsulotomy to restore optical clarity.
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