Efficacy and Safety of Low Target Pressure Trabeculectomy: 2-Year Clinical Results

Purpose: To compare the success and complication rates of low target pressure trabeculectomy (LTT) and conventional trabeculectomy (CT). Methods: A retrospective study was conducted with consecutive patients undergoing trabeculectomy. Twelve eyes of 12 patients underwent LTT, and 17 eyes of 17 patients underwent CT. Surgical success was defined as meeting each target intraocular pressure (IOP) without additional medication or further glaucoma surgery. A Kaplan-Meier survival analysis was used to estimate survival rate. Incidences of surgical complications were also assessed. Results: The median postoperative IOP 2 years after surgery were 10.0 mmHg (interquartile range [IQR] 8.5 - 12.0 mmHg) in the LTT group and 16.0 mmHg (IQR, 14.0 - 18.5 mmHg) in the CT group (P = 0.000). Estimated survival rates for patients who underwent the two types of trabeculectomy were significantly different with all IOP criteria of 10, 12 and 14 mmHg (P < 0.01 for all), except IOP ≤ 18 mmHg. Vision-threatening complications were not found in either group during the observation period. Late-onset bleb leaks occurred in only two eyes in the LTT group but were well treated with autologous blood injection and amniotic membrane transplantation. Conclusion: LTT provided more chances to maintain low postoperative IOP and had no more vision-threatening complication than those of CT.