Massive iatrogenic orbital cysts following glaucoma drainage implant and strabismus surgery

We describe 2 paediatric patients who developed large orbital conjunctival epithelium-lined inclusion cysts postsurgery. Case 1 underwent Ahmed glaucoma valve implant surgery 8 months ago and case 2 underwent strabismus surgery 7 years ago. Both cases had either symptomatic strabismus or a mass causing some degree of proptosis or incomitance due to lesions in the intraorbital space. Following total excision of the cysts all associated symptoms were resolved. Conjunctival cysts following ocular surgery can develop anywhere in the anterior segment; however, large orbital cysts following anterior segment surgery are quite rare. We think that implantation cysts should be considered in the differential diagnosis of patients that have signs of orbital mass with a history of previous anterior segment surgery. Complete excision of the cysts results in resolution of all associated signs and symptoms.