We report a case of spontaneous recovery of an iris cyst with only tuberculosis medication and conservative eye drops when uveitis and angle closure occurred because of a cyst in a patient with peritoneal tuberculosis.

A 49-year-old female who was diagnosed with iritis and treated with steroid eye drops visited our clinic because of decreased visual acuity 1 month prior. There were anterior chamber inflammation cells and an iris cyst completely obstructing the anterior chamber at 12 o'clock. At the time, the patient had been diagnosed with peritoneal tuberculosis in the Department of Internal Medicine and Gynecology and had been treated with surgery and medication. The patient had no past history of glaucoma, but when the iris cyst developed, the intraocular pressure increased to 29 mmHg and anterior inflammatory cells were seen in the range of +1 to +2. The primary lesion of tuberculosis improved and the iris cyst disappeared with treatments involving medication for tuberculosis, steroid eye drops, and glaucoma eye drops, without invasive treatments such as alcohol curettage, laser treatment, or cyst resection.

If an iris cyst is a new lesion of the eye, it is necessary to identify the pattern and cause of the iris cyst first, and if a secondary benign iris cyst is suspected, the primary treatment of the causative disease is necessary rather than prompt invasive treatment.