Abstract
Purpose: :
The purpose of our study was to review the clinical presentation, management and outcome of glaucoma drainage implant (GDI) related conjunctival erosions.
Methods: :
The medical records of subjects who underwent Ahmed valve implantation at Kresge Eye Institute (KEI) between Jan 1998 and Sept 2007 were reviewed. Subjects with tube exposure were identified and their clinical course and outcomes were recorded.
Results: :
Twenty three (10%) of 218 eyes with Ahmed valves implanted at KEI had conjunctival erosion and tube exposure. The mean interval between GDI surgery and tube exposure was 10.1 months (median 3 months, range 6 days to 6.5 years). The mean age was 62 ± 18 years. Eighteen eyes had at least one type of surgery involving conjunctiva prior to GDI including 7 eyes with trabeculectomy with mitomycin C. The patch graft used to cover the tube was tutoplast pericardium in 19 eyes and fascia lata in 4 eyes. Tube exposure was detected at routine visit in 19 eyes (82%), 13 eyes (68%) among them were asymptomatic. Tube exposure in 4 eyes was detected when they presented to the emergency room with painful red eye or blurred vision. The tube exposure was near the limbus in 20 eyes (87%) and near the plate in the remaining 3 eyes. Nineteen eyes were treated prophylactically with topical antibiotics. Postoperatively, in addition to medical therapy, diode laser cyclophotocoagulation was needed in 4 eyes to control intraocular pressure and additional GDI in 2 eyes. Three eyes (13%) developed endophthalmitis after a mean interval of 22 ± 18 days (range 3 days to 40 days) following tube exposure. All 3 eyes with endophthalmitis received intravitreal antibiotics without vitrectomy and 2 of these 3 eyes needed removal of GDI. In eyes with tube exposure but without endophthalmitis, GDI’s were removed in 7 eyes (35%) and were redirected through pars plana in 3 eyes (15%). Post-treatment, 2 of 3 eyes with endophthalmitis regained visual acuity to their pre-infection level. One eye lost visual acuity from 20/400 to counting fingers. Seventeen (85%) of 20 eyes without endophthalmitis maintained pre-exposure visual acuity while 3 eyes had reduction by 1 to 2 lines.
Conclusions: :
A majority of eyes with conjuntival erosions following GDI are asymptomatic. The site of tube should be examined meticulously for conjuntival erosion at every patient visit. When detected, it should be promptly repaired due to the potential progress to endophthalmitis despite use of prophylactic antibiotics.
Keywords: endophthalmitis • intraocular pressure • wound healing