Abstract
Purpose: :
To determine the effectiveness and safety of a second Ahmed valve implant in eyes with refractory glaucoma and indications associated with the need to place a second Ahmed valve in one eye. Intraocular pressure control, the need for additional medical or surgical treatment, complications and changes in vision were studied.
Methods: :
We carried out a retrospective, case series analysis of all patients with two Ahmed valves in one eye placed at different moments.
Results: :
We analyzed 48 eyes of 45 patients (26 females, 57.8%), with a median follow-up of 26.2 months (range 0.5 to 144). The most frequent primary diagnoses associated with the need to place a second Ahmed valve were congenital glaucoma (n=11, 22.9%), followed by primary open-angle glaucoma (n=8, 16.7%) and neovascular glaucoma (n=6, 12.5%). Secondary glaucomas comprised 43.8% of cases (n=21). The 12-year Kaplan-Meier survival rate to maintain intraocular pressures under 18 was 66.3% and below 15 mmHg was 22.1%. Initial mean intraocular pressure was 24 mmHg, and mean IOP at last control was 14mmHg. The average number of surgical procedures for glaucoma control performed before placement of the second valve was 2.6 per eye, the most frequent being perivalvular fibrosis removal. The time elapsed between the implant of the first and second valve averaged 40.6 months. Average post-surgical procedures were 0.5, the most frequent being repositioning of the tube in 13 eyes (27.1%), followed by fibrosis removal in 12 (25%), and subconjunctival bevacizumab in 8 (16.7%). The number of additional drugs required to control intraocular pressure was 4 drugs in 27% of eyes, 3 drugs in 21%, 2 drugs in 25%, 1 drug in 15% and 22% with no medications. The most common complications were corneal decompensation due to tube-endothelial touch (n=8, 16.7%), transient flat anterior chamber in 6 (12.5%), and transient choroidal detachment in 4 (8%). Visual acuity worsened in 33.3% of cases, improved in 20.8%, and remained unchanged in 16.7%.
Conclusions: :
Implanting a second valve is an acceptable alternative for long-term management of partially controlled glaucoma with an initial Ahmed valve, with an acceptable complication rate.
Keywords: clinical (human) or epidemiologic studies: outcomes/complications • intraocular pressure • optic disc