Vol. 43 No. 2 Original Research PDF

Risk Factors for Conjunctival Tube Erosion in Eyes Implanted with Ahmed Glaucoma Valve in a Private Eye Institution in the Philippines

Jovell Ian M. Peregrino, MD, DPBO, Edgar U. Leuenberger, MD, DPBO, Ma. Imelda Y. Veloso, MD, DPBO


To identify the risk factors for conjunctival tube erosion (CTE) in eyes implanted with Ahmed® glaucoma valve (AGV) device.


This is a retrospective study conducted at a private eye institution. Medical records of patients who underwent AGV implantation surgery from January 2004 to December 2013 were reviewed. Eyes with at least 24 months of follow-up and complete records were included. Several variables from the pre-, intra-, and postoperative periods were collected. The primary outcome was development of CTE after AGV surgery. Univariable logistic regression and multivariable analysis were employed.


Forty-six (46) eyes of 45 patients were included in the study. The mean follow-up was 50.2 months (range: 24-140 months). Eight (8) eyes developed CTE (17.4%). Univariable logistic regression analysis identified female gender (P =0.064), presence of diabetes (P =0.083), prior intraocular surgeries (P =0.09), and postoperative use of antiglaucoma medications (P =0.086) to be marginally significant risk factors for CTE. On multivariable analysis, only female gender (OR=15.4, P =0.033) and diabetes (OR=14.1, P =0.031) were found to be significantly associated with CTE.


Risk factors for CTE following AGV implantation include female gender and presence of diabetes.

Keywords: conjunctival tube erosion, Ahmed® glaucoma valve, glaucoma drainage device, glaucoma, autologous scleral flap