# Unilateral Iris Transillumination Resembling BAIT Phenotype Following Contralateral Vitrectomy

## TL;DR

A patient developed unilateral iris transillumination in her left eye after a vitrectomy and infection in her right eye, suggesting a possible protective effect from prior treatments.

## Contribution

This is the first reported case of unilateral BAIT-like phenotype following contralateral vitrectomy and postoperative endophthalmitis.

## Key findings

- The patient developed unilateral iris transillumination in the left eye one month after right eye vitrectomy and treatment for endophthalmitis.
- The right eye remained unaffected, suggesting prior treatments may have a protective role against acute iris transillumination.
- The left eye's transillumination matched the BAIT syndrome phenotype but was unilateral, not bilateral.

## Abstract

Objective: This study is aimed at describing a unilateral presentation of acute iris transillumination following contralateral vitrectomy with postoperative endophthalmitis.

Methods: This case study is based on the medical record of a patient who presented to our hospital in 2017.

Results: A 70-year-old female patient presented to our department with metamorphopsia and decreased vision in the right eye. She was diagnosed with a Stage 3 macular hole in the right eye for which she underwent 23G pars plana vitrectomy with gas tamponade. Postoperative topical treatment of tobramycin/dexamethasone was administered. Nine days after surgery, she presented to a different medical center with postoperative endophthalmitis in the right eye. Oral moxifloxacin was administered, an intravitreal injection with vancomycin was performed, and topical treatment with dexamethasone/chloramphenicol and neomycin/polymyxin B/dexamethasone was started. One month after surgery, she presented again to our department, this time with scleritis with associated anterior uveitis of the left eye. She was treated with oral ibuprofen, topical prednisolone acetate, and atropine sulfate, which resulted in clinical resolution. Three weeks after this episode, the left eye showed patchy transillumination of the iris matching the bilateral acute iris transillumination (BAIT) syndrome phenotype; however, the iris in the right eye remained normal.

Conclusion: To the best of our knowledge, this case is the first to show a unilateral phenotype of BAIT after contralateral vitrectomy. This suggests that previous vitrectomy, injection of vancomycin, or topical corticosteroids or chloramphenicol could be protective against the development of acute iris transillumination.