Antony William, Martin S Spitzer, Deshka Doycheva, Spyridon Dimopoulos, Martin Alexander Leitritz, Bogomil Voykov

The aim of this study was to compare the long-term outcomes of ab externo trabeculotomy in primary open-angle glaucoma (POAG) and uveitic glaucoma (UG). This was a retrospective single-center case series study. Twenty eyes of 17 patients with POAG and 22 eyes of 18 patients with UG were included in this study. The medical records of all consecutive patients with POAG and UG who underwent ab externo trabeculotomy since 2004 were reviewed. The main outcome measure was change in median intraocular pressure (IOP). Success was defined as IOP ≤21 mmHg (success 1) and IOP ≤21 mmHg and at least 25% reduction from baseline (success 2). In the POAG group, the median IOP decreased significantly from 22 mmHg (95% CI 21-25 mmHg; n=20) at baseline to 14 mmHg (95% CI 12-16; n=13) after 4 years, P<0.001. In the UG group, the median IOP decreased significantly from 27 mmHg (95% CI 24.5-30.5 mmHg; n=22) at baseline to 12 mmHg (95% CI 9-15 mmHg; n=15) after 4 years, P<0.001. Seven eyes in the UG group failed within the first year after surgery compared to none in the POAG group. Of these, four eyes had Fuchs' uveitis syndrome and two had granulomatous uveitis. No sight-threatening complications occurred in both POAG and UG groups. Ab externo trabeculotomy effectively reduced IOP in both UG and POAG groups. However, the success rates in the UG group were significantly lower due to the high failure rate in patients with Fuchs' uveitis syndrome and granulomatous uveitis. The procedure demonstrated a high safety profile in both UG and POAG patients.