# A Novel Scleral Tunnel Technique for the Prevention of Ahmed Glaucoma Valve Tube Exposure

## TL;DR

A new minimally invasive technique is introduced to prevent tube exposure after Ahmed glaucoma valve implantation.

## Contribution

A novel scleral tunnel technique is proposed to prevent tube exposure during AGV implantation.

## Key findings

- The technique uses a 22-gauge needle to create a scleral tunnel for tube insertion.
- No postoperative complications, including tube exposure, were observed in the study.
- The method is effective when used with or without pars plana vitrectomy.

## Abstract

Tube exposure after Ahmed glaucoma valve (AGV) implantation is a serious complication in eyes with glaucoma. This study aimed to present an effective and minimally invasive scleral tunnel technique for preventing tube exposure. A scleral tunnel was created using a 22-gauge needle between two scleral incisions. The scleral incisions were made 2 mm and 8 mm from the limbus for a simple AVG implantation, and 4 mm and 8 mm from the limbus for an AVG implantation performed together with pars plana vitrectomy (PPV), in which a trocar for the PPV was inserted through the scleral incision at the 4 mm position. After trimming the tube to an appropriate length, it was inserted into the scleral tunnel created by the 22-gauge needle. The tube was then removed from the sclera, and its tip was inserted into the posterior chamber through the scleral incision. After confirming the insertion of the tube into the posterior chamber, the Tenon’s capsule and conjunctiva were sutured using 8-0 Vicryl sutures. No postoperative complications, including tube exposure, were observed. This novel technique is an effective and minimally invasive method for preventing tube exposure after AGV implantation.