Unilateral Urrets-Zavalia syndrome after Implantable Collamer Lens implantation: a case report and review of the literature

BACKGROUND: Fixed dilated pupil after ophthalmic surgery or Urrets-Zavalia syndrome occurs after anterior segment surgery and usually relates to postoperative elevation of intraocular pressure. Urrets-Zavalia syndrome results in complaints of glare, halo, and photophobia. Retention of the viscoelastic agent during Implantable Collamer Lens implantation can result in postoperative elevation of intraocular pressure and Urrets-Zavalia syndrome. However, reversibility of pupillary dilatation is possible in some cases. CASE PRESENTATION: A 20-year-old Thai man with myopic astigmatism in both eyes underwent Implantable Collamer Lens implantation in the right eye. The preoperative slit-lamp examination of both eyes was normal, and no ectatic changes were detected from corneal tomography. One hour after the uncomplicated surgery of the right eye, intraocular pressure increased to 48 mmHg and was immediately controlled with antiglaucoma medications. Postoperative pupillary dilatation was detected, presumably due to effect of preoperative application of mydriatic drops. At postoperative day 1, the right pupil remained dilated but still reactive to light and pilocarpine 2% eye drops. Two weeks later, the left eye underwent the Implantable Collamer Lens implantation and showed neither postoperative increase in intraocular pressure nor postoperative pupillary dilatation. Two months after surgery, the dilatation of the right pupil partially reversed. CONCLUSIONS: The findings of the right eye suggested diagnosis of Urrets-Zavalia syndrome. Compared with former reports, we noted an association between immediate control of elevation of postoperative intraocular pressure, light reactivity of the dilated pupil, and reactivity to pilocarpine 2% eye drops as potential predictors for reversibility of Urrets-Zavalia syndrome.