Bilateral Urrets-Zavalla Syndrome After Uneventful Descemet’S Membrane Endothelial Keratoplasty

Urrets-Zavalia Syndrome (UZS) stands out as a rare yet clinically consequential complication associated with ophthalmic surgery, marked by the emergence of a fixed and dilated pupil¹. While it was originally described post penetrating keratoplasty (PKP) in patients with keratoconus and its prevalence is notably higher following PKP, instances of UZS have been documented in the context of other procedures, including intraocular lens implantation, Descemet-stripping endothelial keratoplasty (DSEK) and Descemet membrane endothelial keratoplasty (DMEK). We report a unique case of bilateral UZS after uneventful DMEK surgeries, highlightinga rare but possible complication after DMEK.

Sussex Eye Hospital, University Hospitals Sussex NHS Foundation Trust, Brighton, UK

This case involves a 71-year-old male who previously underwent bilateral uneventful phacoemulsification cataract surgeries, resulting in suboptimal visual outcomes attributed to Fuchs endothelial dystrophy. Pre-intervention, the patient presented with a best-corrected visual acuity (BCVA) of 6/18 in the right eye and 6/12 in the left eye, accompanied by normal intraocular pressures. Uncomplicated Descemet membrane endothelial keratoplasty (DMEK) was performed on the right eye in January 2022 with normal intraocular pressures and BCVA improvement to 6/6 at 2 months. However, persistent, otherwise asymptomatic pupillary dilation to approximately 5.5 mm was noted and managed conservatively. Following further visual deterioration in the other eye, the patient's desire for DMEK prompted discussion regarding the second potential manifestation of Urrets Zavalla syndrome. The left eye underwent uncomplicated DMEK in August 2023, but postoperative assessment on day 1 revealed misdirection of tamponade gas behind the iris, resulting in angle closure. This necessitated anterior chamber reformation and graft rebubbling in subsequent surgical intervention due to recurrence on day 2. The graft eventually settled, yielding normal pressures and BCVA improvement to 6/9 at six weeks post-surgery, with persistent pupil dilation measuring around 6 mm, managed conservatively. Both eyes demonstrated excellent recovery post-procedure and improvement in visual acuity.

This case is the first documentation of bilateral Urrets-ZavaliaSyndrome (UZS) following uneventful DMEK surgeries. Proposed pathophysiological mechanisms include elevated intraocular pressure (IOP), causing iris compression against the cornea. Similarly, our case suggested an association with elevated post-surgical IOP. However, unlike transient pupillary dilation, our case demonstrated permanent unresolved dilation. We attributed this to degree of iris injury, postoperative IOP, and patient age. Treatment for UZS is limited therefore preventing and controlling risk factors are crucial for enhancing vision quality. Our presentation of bilateral UZS adds valuable insights to the growing body of knowledge surrounding this rare syndrome.