Background: Most epithelial cysts of the anterior chamber ("iris stromal cysts") occur after penetrating ocular injuries and represent secondary epithelial ingrowth. Primary iris stromal cysts are less common and mostly congenital. 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 was no history of trauma and no signs of preceding ocular injury at slit-lamp examination. The cyst was surgically removed by iridocyclectomy. Postoperatively the patient developed cataract and macular edema. A phacoemulsification with posterior chamber lens implantation as well as a systemic treatment with steroids and acetazolamide were necessary. Until now, two years after surgery, the cyst did not recur.
Conclusions: Primary iris stromal cysts also occur in adults. In contrast to previous reports the cyst of our patient has caused acute symptoms.