Points to Ponder for NEET-PG, FMGE & NEXT
- Ectopia lentis can be caused by acquired conditions (trauma, inflammation, cataract) or congenital syndromes (Marfan, Weill-Marchesani, homocystinuria).
- Marfan syndrome’s association with bilateral superotemporal ectopia
- Weill-Marchesani syndrome is associated with inferior ectopia lentis developing later in life.
- Ectopia lentis as a potential complication of hypermature cataracts and large eyes.
Definition: Ectopia lentis refers to the displacement of the crystalline lens from its normal position in the eye. This displacement can be:
- Complete (luxation): Lens completely dislocated from its position, rendering the eye functionally lensless (aphakic).
- Partial (subluxation): Lens partially displaced, remaining partly within the pupillary area.
Causes
Acquired
- Trauma: Blunt or penetrating injury to the eye can disrupt the zonules (fibers that hold the lens in place).
- Inflammation: Chronic inflammatory conditions like cyclitis (inflammation of the ciliary body) or syphilis can weaken the zonules.
- Hypermature cataract: As a cataract progresses, the lens material can liquefy and disrupt zonular attachments.
- Large eye: Conditions like high myopia (nearsightedness) or buphthalmos (enlarged eyeball) can stretch the zonules, predisposing to ectopia lentis.
Congenital
- Familial ectopia lentis: Inherited condition with variable expressivity (severity).
- Aniridia: Congenital absence of the iris (colored part of the eye) is often associated with ectopia lentis.
- Marfan syndrome: Connective tissue disorder with a high prevalence (80%) of bilateral ectopia lentis. Subluxation is most commonly superotemporal (upward and outward).
- Weill-Marchesani syndrome: Connective tissue disorder with a 50% chance of developing ectopia lentis. Subluxation typically occurs in an inferior direction (downward) during late childhood or early adulthood.
Homocystinuria: Inherited metabolic disorder that can cause ectopia lentis due to abnormal connective tissue development.
