Evaluation of Tranilast to Treat Pterygium Before Excision

Overview

Recurrent or secondary pterygium often has often a growing fibrovascular tissue more exuberant than the primary. Histological findings differ from the primary, since the typical changes in the degenerate connective tissue are absent. The strong immunoreactivity and release of basic fibroblast growth (b-FGF) in cultured fibroblasts of recurrent pterygia suggest that fibroblasts may play an important role in pterygium recurrence. Tranilast used is an antiallergic drug that has an inhibitory effect on the release of chemical transmitters, such as histamine and leukotrienes from mast cells as well as a suppressive effect on vascular permeability.This drug also reduces TGF-β1 production and collagen synthesis in various cells. Tranilast might reduce pterygium recurrence by suppressing TGF-β1 synthesis in conjunctival fibroblast after pterygium surgery. The investigators want to confirm these findings and also compare the recurrence rate between the two types of surgery. Tranilast might be an alternative of mitomycin use, and also less toxic. This study aim to compare the effectiveness of preventing recurrence by using tranilast by topical subconjunctival administration previous to conjunctival autograft transplantation surgery in cases of primary pterygium, and will be perform clinical evaluation and TGF-beta-1 immunohistochemical detection by the anti-TGF-beta 1 antibody as well as fibroblast culture.

This is a prospective, randomised, control trial of 50 participants. Twenty five patients in each arm. Twenty five patients undergo standard pterygium excision with the fibrin glue (Tissucol) conjunctival autograft . Twenty five patients undergo pterygium surgery with fibrin glue (Tissucol), and subconjunctival injection of 0.1 ml of Tranilast 1.0% in the head of pterygium 30 days before surgery. Participants will be reviewed, selected, and consented on a pre-assessment day. Surgery will be performed 4 at a time on an all day surgery operating list. Randomisation of the surgery type will be done at the time of surgery after the pterygium has been excised and the autograft taken. The surgeries will perform by a single surgeon (Almeida Jr, GC). Follow-up will occur at week 1,4, 26, 52. Slit lamp examination will indicate pterygium recurrence. Corneal recurrence will consider when it 0.5 mm of invaded conjunctival tissue,in the clear cornea from the anatomical limbus. The conjunctival recurrence will consider of any size conjunctive fibrovascular invasion inside the graft. The localization and of immunohistochemical will be perform for TGF-B.