Third surgery of Ahmed valve tube exposure: A case report

Abstract

Aims/Purpose: Exposure of the glaucoma drainage devices tube is one of the main postsurgical complications, and it is important not to delay treatment in order to avoid serious situations such as endophthalmitis. Our aim is to report a case of a patient with an Ahmed valve tube exposure who had undergone two previous surgeries unsuccessfully.Methods: We present the case of a 71‐year‐old male patient with diabetic retinopathy with an Ahmed valve in his left eye for 4 years due to neovascular glaucoma. In the first surgery the tube was positioned in the posterior chamber. After two months, displacement of the tube was observed so it was repositioned in anterior chamber with apposition of Ologen® on temporal, superior sclera. Three years later, exposure of the valve tube was seen and it was covered with Tutopatch® and conjunctiva. Recently, on examination, exposure of the valve tube was observed once again. We removed the epithelial cells from the scleral bed with absolute alcohol, after that we revitalized the conjunctival borders of the wound and covered the tube with fascia lata. Finally, we sutured the conjunctiva without tension.Results: At the moment, the tube remains covered and the superior temporal conjunctiva has a good appearance.Conclusions: Different repair techniques are described in the bibliography, such as conjunctiva covering, grafting of different materials, repositioning of the tube with grafting, valve removal and implantation in a different quadrant and even definitive removal of the valve. In our case we used a fascia lata graft, which is associated with a lower risk of subsequent exposure. The previous preparation of the scleral bed and the edges of the conjunctiva, as well as a conjunctival suture free of tension and traction are key to obtaining a good result.