A Case of Annular Iris Cyst Diagnosed With the Help of Ultrasound Biomicroscopy.

Purpose: To report a case of annular iris cyst presenting as a secondary angle closure managed with Nd:YAG laser iridotomy.

Design: Case report.

Methods: Institutional review board exemption for this case report was obtained from the institutional ethics committee, Aravind eye hospital, Tirunelveli. All research adhered to the tenets of the Declaration of Helsinki. Informed consent was obtained.A 45-year-old woman presented with a 2-week history of sudden onset of pain and redness in the right eye. Slit-lamp biomicroscopy showed corneal edema, with the shallow anterior chamber, convex bowing of iris, irregular shape of the pupil, and glaucomflecken on the clear lens. Ultrasound biomicroscopy revealed an annular iris cyst of the iris pigment epithelium. Nd:YAG laser iridotomy was done to drain the cyst and relieve the angle closure.

Results: Laser treatment resulted in the collapse of the cyst, confirmed by ultrasound biomicroscopy and disappearance of the subject symptoms.

Conclusion: Iris cysts are usually benign in nature. An annular iris cyst is a rare presentation. They can present with a secondary angle closure as in our report. Correct diagnosis and timely intervention bring about a desirable result. With this report, the authors aim to catalog and familiarize ophthalmologists with a rare ocular pathology and its management.