Glaucoma · practice question
Which factor most directly determines that the lid turns in rather than out?
[READINESS SEED] An elderly patient has horizontal lower-lid laxity, disinserted lower-lid retractors, and mild enophthalmos. The lid turns inward rather than sagging outward. Which factor most directly determines that the lid turns in rather than out?
Show the answer and explanationAnswer and explanation
Answer: A. Preseptal orbicularis override
All four involutional factors coexist, but the preseptal orbicularis riding up over the pretarsal portion is what rotates the tarsus inward — the feature that makes the same lax lid an entropion rather than an ectropion. Laxity, retractor disinsertion, and enophthalmos set the stage; orbicularis override turns the lid in.
Clinical pearl: This is why taping or a temporizing everting suture, which oppose the orbicularis override, can immediately relieve an involutional entropion before definitive repair.