Urrets-Zavalia Syndrome After Dmek: Role Of Inferior Peripheral Iridectomy And Early Iop Control In Prevention

To describe the clinical course, mechanisms, and preventive strategies of Urrets-Zavalia syndrome (UZS) after Descemet membrane endothelial keratoplasty (DMEK) and to integrate a structured analysis of the published literature to identify modifiable surgical factors. Particular emphasis is placed on the role of early postoperative intraocular pressure elevation, aqueous flow dynamics in the presence of a large gas bubble, and the relevance of peripheral iridectomy location in preventing pupillary block and subsequent iris ischemia.

Oftalmocenter – Centro Especializado de Oftalmología and Clínica de Ojos Larco Visión, Quito, Ecuador. Tertiary referral center for corneal transplantation with standardized DMEK technique, multimodal postoperative evaluation, and long-term follow-up.

A 53-year-old woman with prior Artisan phakic intraocular lens implantation developed corneal decompensation and underwent uneventful DMEK using 20% SF₆ gas tamponade (80% fill). No inferior peripheral iridectomy was performed because a large superior iridectomy was present. Postoperative intraocular pressure, graft attachment, pupillary changes, and visual outcomes were prospectively documented. A structured PubMed review of reported UZS after DMEK was performed, analyzing tamponade type, iridectomy status and location, postoperative intraocular pressure, management, and final visual acuity.

On postoperative day 1, intraocular pressure increased to 37 mm Hg despite a well-attached graft and a patent superior iridectomy, requiring partial gas release. By day 7, a fixed dilated pupil with posterior synechiae developed while corneal transparency improved. Anterior subcapsular cataract required phacoemulsification with synechiolysis using endothelial-protective techniques. Final best-corrected visual acuity reached 20/30 with a clear graft and stable intraocular pressure. Literature analysis showed that UZS occurs with both air and SF₆ and is consistently associated with early postoperative ocular hypertension. Eyes without an inferior peripheral iridectomy showed a higher rate of permanent pupillary abnormalities.

Urrets-Zavalia syndrome after DMEK is primarily caused by early postoperative intraocular pressure elevation in the presence of impaired inferior aqueous flow. A patent superior iridectomy does not prevent pupillary block and may generate a false sense of protection. Integration of our findings with the literature indicates that an inferior peripheral iridectomy is the most effective preventive measure, as it provides direct aqueous egress beneath a large gas bubble. Strict day-1 intraocular pressure control and individualized gas management are essential. With timely staged treatment, excellent long-term visual outcomes can still be achieved.