Cataract: Clinical Overview
NEET PG / Board Examination Essentials
1. Definition
A cataract is any opacity of the crystalline lens of the eye, leading to a decrease in visual acuity and potential blindness. It represents a major global cause of reversible vision impairment.
2. Etiology
| Category | Key Examples |
|---|---|
| Age-Related | Senile cataract (most common). |
| Congenital/Developmental | Rubella, Galactosemia, Down Syndrome. |
| Metabolic | Diabetes Mellitus (osmotic changes), Hypocalcemia. |
| Secondary/Traumatic | Corticosteroids (long-term use), ionizing radiation, penetrating eye injury. |
3. Management
- Medical: No effective pharmacological cure exists to reverse opacities. Lifestyle modification (e.g., UV protection) may slow progression.
- Surgical:
- Phacoemulsification (Phaco): The gold standard. Uses ultrasonic energy to emulsify the lens, followed by aspiration and Intraocular Lens (IOL) implantation.
- Small Incision Cataract Surgery (SICS): A cost-effective, manual technique often used in high-volume settings.
4. NEET PG High-Yield Pearls
- Type: The most common form of age-related cataract is Nuclear Sclerosis.
- Diabetes: “Snowflake” cataracts are characteristic of juvenile-onset diabetes.
- Complications: Phacomorphic/Phacolytic glaucoma, lens subluxation.