Iridotomy Requirement with Vitrectomy and Silicone Oil Placement

Risk-Based Approach to Iridotomy

The American Academy of Ophthalmology guidelines identify silicone oil with forward displacement of the lens-iris diaphragm as a posterior pushing mechanism causing secondary angle closure in aphakic eyes undergoing silicone oil tamponade, which requires prophylactic iridotomy in most cases 1
Aphakic eyes undergoing silicone oil tamponade should routinely receive an inferior peripheral iridectomy to prevent pupillary block glaucoma, as recommended by the American Academy of Ophthalmology 1

Silicone oil acts as a posterior pushing force, displacing the lens-iris diaphragm anteriorly, which can cause pupillary block in eyes with silicone oil tamponade 1
Silicone oil physically blocks the pupil, unlike primary pupillary block where aqueous cannot flow from posterior to anterior chamber, and parasympathomimetic treatment is ineffective in these cases 3
The use of mydriatics may be more effective in treating secondary pupillary block caused by silicone oil or an intraocular lens 3

Inadequate sclerotomy closure is a common cause of hypotony, and meticulous closure with mattress sutures using long scleral passes is essential, as emphasized by medical guidelines 4