Incisional therapies: Trabeculectomy surgery

Abstract

Trabeculectomy with an antimetabolite is considered the “gold standard” for the surgical management of glaucoma.The concept of the operation is to lower the IOP by creation of a fistula between the anterior chamber of the eye and the sub-Tenon and subconjunctival space, so that the aqueous humor is finally collected into the episcleral and conjunctival veins.The bleb surgical site is in the upper globe, preferably under the upper eyelid in order to reduce infections or bleb leakage. No scleral flap size or shape has been proven to be superior.The desired size of the ostium should be more then 40'50 mm in diameter, because below that size, significant resistance to the physiological aqueous outflow can still remain A fornix-based conjunctival incision is preferred over the limbal-based fashion due to lower postoperative complications. The outcome of filtration surgery is improved by the use of antimetabolites, mainly 5-fluorouracil and mitomycin'C.Their main action is inhibition of the fibroblast proliferation and activity, thus achieving higher success rates, lower IOP, and fewer glaucoma medications.Unfortunately, these adjunctive agents increase the risk of vision-threatening complications.The nylon suture is preferred to suture the sclera flap and conjunctiva because of its low tendency to create anti-inflammatory response.Thorough postop treatment and follow-up are mandatory to a successful outcome, mainly to keep the fistula open and to prevent the formation of the conjunctival “ring of steel.”