In an aphakic eye filled with silicone oil following complex retinal detachment surgery, an inferior peripheral iridectomy (Ando iridectomy) is created. Its primary purpose is to:
- A Prevent migration of silicone oil into the subretinal space
- B Allow aqueous access to the anterior chamber and prevent pupillary block glaucoma ✓
- C Reduce postoperative inflammation by draining fibrin
- D Improve visualization of the peripheral fundus during oil removal
Correct answer: B. Allow aqueous access to the anterior chamber and prevent pupillary block glaucoma
Explanation
Silicone oil is buoyant and, in an aphakic eye, sits against the pupil like a valve, blocking aqueous flow from the posterior chamber into the anterior chamber. This produces pupillary block glaucoma and keeps aqueous away from the corneal endothelium, accelerating decompensation. B patent inferior iridectomy bypasses the oil bubble, maintaining aqueous circulation to nourish the cornea. Oil does not pass through a small inferior iridectomy because of its buoyancy.
Reference: Ryan's Retina, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.