Primary iris stromal cyst in an adult with unusual symptoms

Background: Most epithelial cysts of the anterior chamber ("iris stromal cy sts") occur after penetrating ocular injuries and represent secondary epith elial ingrowth. Primary iris stromal cysts are less common and mostly conge nital. Acquired primary iris stromal cysts in adults are extremely rare and cause less often symptoms than congenital cysts. Patient: A 41-year old patient presented with sudden loss of visual acuity, epiphora and photophobia of his right eye. A large iris cyst was found in the nasal lower quadrant of the anterior chamber. It had not been present 3 years before when the patient was last seen by an ophthalmologist. There w as no history of trauma and no signs of preceding ocular injury at slit-lam p examination. The cyst was surgically removed by iridocyclectomy. Postoper atively the patient developed cataract and macular edema. A phacoemulsifica tion with posterior chamber lens implantation as well as a systemic treatme nt with steroids and acetazolamide were necessary. Until now, two years aft er surgery, the cyst did not recur. Conclusions: Primary iris stromal cysts also occur in adults. In contrast t o previous reports the cyst of our patient has caused acute symptoms.