Surgical outcomes of primary filtering surgery in secondary childhood glaucoma patients: a retrospective cohort study.

Purpose: To evaluate the long-term outcomes of primary filtering surgery, including trabeculectomy and combined trabeculotrabeculectomy (CTT), in secondary childhood glaucoma (SCG) patients.

Study design: Retrospective cohort study.

Methods: SCG patients, who underwent primary filtering surgery at two tertiary hospitals between 2008 and 2018, were reviewed. Surgical success was defined as an intraocular pressure (IOP) between 5 to 21 mmHg. Failure was defined as IOP outside those criteria for two consecutive visits, the need for additional surgery, or loss of light perception. Surgical success was evaluated using the Kaplan-Meier method.

Results: Sixty-four eyes (50 patients) were included. Glaucoma associated with non-acquired ocular anomalies (SCG-O) included 31 eyes from 23 patients. Median age and follow-up time were 63.6 and 18 months, respectively. Overall success probabilities were 57.8% at 1 year, 55.1% at 3 years, and 50.1% at 5 years. For trabeculectomy (55 eyes), the success probabilities were 59.5% at 1 and 3 years, and 52.0 % at 5 years. For CTT (9 eyes), the success probabilities were 44.4% at 1 year, decreasing to 33.3% at 3 and 5 years. There was no statistically significant difference between trabeculectomy and CTT. Hypotony was the most common early complication. Two eyes developed phthisis bulbi.

Conclusions: Primary filtering surgery in SCG patients showed a significant drop in the success rate to about 60% within the first year, followed by a slight decline thereafter, with a long-term success rate around 50%.