Factors associated with conjunctival erosions after ahmed glaucoma valve implantation

Abstract

Purpose:To investigate the frequency of conjunctival erosions in a series of patients who underwent Ahmed valve implantation in a tertiary referral center and to study risk factors associated with the conjunctival erosions.Methods:This is a single-center, retrospective case-control study of all patients who underwent Ahmed valve implantation between October 2006 and July 2016 at the Kresge Eye Institute in Detroit, Michigan. The series consisted of 306 eyes (277 patients) that underwent Ahmed valve implantation. The rate of conjunctival erosions was determined. Univariate, bivariate, and Cox-proportional hazard analyses were performed to identify factors associated with conjunctival erosions.Results:During the study period, 23 erosions occurred in 306 eyes (7.52%). Aphakia was significantly more common in eyes with erosions (P < 0.05). Aphakia (P = 0.02), uveitic glaucoma (P = 0.03), and longer post-operative use of topical steroids (P < 0.04) significantly increased the risk of erosions based on the Cox model. There were similar rates of erosions with each type of patch graft. No conjunctival erosion was observed after using the modified scleral tunnel method (n = 10).Conclusions:The overall erosion rate was 7.52% in our series. Uveitic glaucoma, aphakia, and longer post-operative use of topical steroids were significantly associated with conjunctival erosions.

Long-term surgical outcomes of two different Ahmed Valve implantation techniques in refractory glaucoma: Scleral flap vs scleral tunnel

“…After comparing different preoperative parameters as well as the etiology of glaucoma in the 11 eyes with conjunctival erosion, we found no other specific risk factors apart from the previous glaucoma surgery and the tube implantation technique. Because of good results after antimetabolite use 4,33,41 and contrary to other previous studies without antimetabolites use, 14,[23][24][25][26]35 we routinely apply intraoperative MMC to all eyes undergoing these procedures. While MMC could provoke nonspecific cytotoxicity, 42 no conjunctival erosion occurred in the tunnel group in our study.…”

“…Although the scleral flap technique is widely used, 1,9,21 the scleral tunnel technique has been investigated only in a few studies with a relatively small number of patients and only short follow-up periods. 17,19,20,[22][23][24][25][26] Moreover, these studies did not use adjunctive mitomycin C (MMC) which by itself can cause conjunctival melting and erosion.…”

Five-Year Outcomes of Graft-Free Tube Shunts and Risk Factors for Tube Exposures in Glaucoma

“…Currently, there is no consensus on risk factors for tube exposure. Supplemental Digital Content 3, http://links.lww.com/IJG/A797 is a summary of 8 studies using glaucoma drainage devices (GDD) with patch grafts investigating risk factors of exposure 16,21,23–28 . Sex (female), 23,27 ethnicity (White 23 and Hispanic 21 ), type of glaucoma (uveitic glaucoma 24,25 and neovascular glaucoma 21 ), long-term use of topical steroids post-op, 25 and combined surgeries 21,26 were associated with significantly higher risk of tube exposures in at least 2 of 8 studies (Supplemental Digital Content 3, http://links.lww.com/IJG/A797).…”

“…com/IJG/A797 is a summary of 8 studies using glaucoma drainage devices (GDD) with patch grafts investigating risk factors of exposure. 16,21,[23][24][25][26][27][28] Sex (female), 23,27 ethnicity (White 23 and Hispanic 21 ), type of glaucoma (uveitic glaucoma 24,25 and neovascular glaucoma 21 ), long-term use of topical steroids post-op, 25 and combined surgeries 21,26 were associated with significantly higher risk of tube exposures in at least 2 of 8 studies (Supplemental Digital Content 3, http://links.lww.com/IJG/A797). Despite being tested in many studies, systemic disease (diabetes and hypertension), type of GDD, GDD location, type of patch graft, and number of past ocular surgeries were not associated with an increased risk of tube exposures.…”

Limbal reconstruction in uveitic glaucoma patient with exposed Ahmed valve coincident with corneal melting and iris prolapse using multiple corneoscleral allografts

“…However, tube erosion is a serious situation with higher rates in uveitic glaucoma patients and withholds devastating possibly sight-threatening complications [ 4 ]. Several authors have proposed different tissues for the graft, including autologous or human donor sclera, pericardium, dura mater, cornea or human cadaveric fascia lata, amniotic membrane, autologous tenon, and expanded polytetrafluoroethylene, the same materials that can be used initially to cover the implanted tube [ 1 , 5 ].…”