Success of Primary Trabeculectomy in Advanced Open Angle Glaucoma.

AIM: The study assesed trabeculectomy survival in advanced open angle glaucoma (OAG).

METHODS: This is a retrospective longitudinal study in advanced OAG undergoing primary trabeculectomy. Clinical and demographic parameters were recorded. Surgical survival (qualified/complete) was calculated by Kaplan-Meier analysis for multiple upper limits of intraocular pressure (IOP) with/without medication (≤21 mmHg, ≤18 mmHg, ≤15 mmHg, ≤12 mmHg); Cox hazard ratio analysis identified parameters influencing survival.

RESULTS: We included 165 eyes from 165 OAG patients: primary forms (POAG) - 86 eyes and secondary (pseudoexfoliative, SOAG) - 79 eyes; mean follow-up interval was 36.21 ± 13.49 months. Clinical parameters were comparable between sub-groups at baseline, except a higher IOP in SOAG vs POAG (36.6 ± 13.2 vs 32.7 ± 11.1 mmHg, p = 0.04); IOP reduction was similar (SOAG vs POAG) 53.93% vs 56.19%, p = 0.45, yet longer hospitalization (8.47 ± 4.39 (SOAG) vs 6.69 ± 3.01 days (POAG), p=0.03) and more medications (0.65 ± 0.24 vs 0.36 ± 0.16, p = 0.05) were needed to achieve comparable final IOP (16.0 ± 9.1 vs 15.1 ± 7.8 mmHg, p = 0.45). Kaplan Meier survival analysis applied for IOP ≤21 mmHg, ≤18 mmHg, ≤15 mmHg and ≤12 mmHg, revealed complete success in 26.2%, 27.3%, 34.5% and 54.6% eyes, respectively; qualified success was found in 45.7%, 48.6%, 77% and 88.6% eyes, respectively. Multiple medications at baseline diminished survival in all tested models (hazard ratio HR > 1, p<0.05), while 5FU+needling improved survival, mostly if combined with lower IOP regime: HR = 0.15, 95% CI = [0.07 -1.12], p = 0.06, if IOP ≤15 mmHg and HR = 0.09, 95% CI = [0.02-1.25], p = 0.06, if IOP ≤12 mmHg.

CONCLUSION: Trabeculectomy in advanced OAG reached very good survival rates (77% and 88.6%) at 36 months postoperative, if IOP could be maintained ≤15 mmHg, respectively ≤12 mmHg with medication and additional needling+5FU maneuvers. Specific factors influencing survival were identified for each success definition.