Urrets–Zavalia Syndrome of Unresolving Mydriasis Following Endocyclophotocoagulation Combined with Phacoemulsification

Aim and background: Combined endocyclophotocoagulation and phacoemulsification (ECP/Phaco) are uncommonly associated with complications.We present the first case of a rare complication following ECP/Phaco.Case description: A 72-year-old patient with dense nuclear sclerotic cataracts and primary open-angle glaucoma (POAG) underwent bilateral surgery uneventfully.He experienced a brief episode of postoperative elevated intraocular pressure (IOP), but only one eye with a lower baseline IOP developed a dilated pupil.No pupillary response was observed after applying 4% pilocarpine.The fixed mydriasis persisted without reaction to light or near stimulus, and the best-corrected vision (BCVA) was 20/30 in the affected eye.Conclusion: This case reports a possible rare complication when undergoing ECP/Phaco therapy.The pathogenesis of Urrets-Zavalia syndrome is unknown, but we hypothesized that eyes with more pronounced increases in IOP from baseline may be more susceptible to ischemic injury to the pupillary sphincter, resulting in a chronically dilated pupil.Clinical significance: Even a modest transient rise in postoperative IOP in a glaucomatous eye with normal baseline IOP could result in a chronically dilated pupil.