Urrets-Zavalia syndrome following penetrating keratoplasty for keratoconus

Background Urrets-Zavalia syndrome (UZS) consists of a fixed dilated pupil associated with iris atrophy. It is a poorly understood complication following penetrating keratoplasty (PKP) for keratoconus (KC). In this work, we aim to establish the incidence, visual outcomes, and an understanding of UZS. Methods This was a retrospective single-center study in a tertiary eye service in the United Kingdom of consecutive patients with UZS following PKP for KC in a 10-year period. Post-operative complications, including raised intraocular pressure (IOP), were recorded. UZS patients and age-matched control patients who had undergone PKP for KC without developing UZS attended a comprehensive clinical assessment. Anterior segment indocyanine green (ICG) angiography assessed iris perfusion. Results The incidence of UZS was 16.2 %. There was no difference in LogMAR VA or Pelli–Robson contrast sensitivity between groups. There was higher first-day post-operative IOP in UZS ( p = 0.02). UZS patients had increased pupil size ( p = 0.09) with reduced response to pilocarpine 2 % ( p