Purpose To report the largest cluster of Urrets–Zavalia Syndrome (UZS), which occurred as a sequel of toxic anterior segment syndrome (TASS) after uneventful cataract surgery, and to evaluate the possible causes and risk factors to prevent additional cases.

Setting Department of Ophthalmology, Liaquat University of Medical & Health Sciences, Hyderabad, Pakistan.

Design Prospective Case Series.

Methods 15 consecutive TASS cases following uneventful cataract surgery were evaluated for potential causes and risk factors. Main outcome measures included visual acuity, anterior segment reaction, corneal oedema, intraocular pressure, pupillary reaction and response to topical and/or systemic steroid therapy at first day, first week and first month postoperatively.

Results The TASS incidence in this study was 0.08%. All cases presented with corneal oedema, anterior chamber reaction and fixed dilated pupils on first postoperative day. One month postoperatively, the anterior segment inflammation improved considerably in all patients. There was a statistically significant difference between the mean Best-corrected visual acuity (BCVA) at first postoperative day (2.32±0.93 LogMAR) and mean BCVA at 1 month (0.49±0.12 LogMAR) (p=0.0001). The rate of UZS in this study was 93%. Ringer lactate solution was found to be the offending agent of TASS, and replacing it brought a halt to this cluster.

Conclusions Timely diagnosis, steroid therapy and close monitoring are the main keys for properly managing TASS. To our knowledge, we report, for the first time, the largest cluster of UZS occurring as a sequel of TASS.