Application of EX-PRESS implants type P-50 in the surgical treatment of open angle glaucoma in pseudophakic eyes

Introduction
To report the efficacy and safety of the EX-PRESS Glaucoma Filtration Device type P-50 in pseudophakic eyes with primary or secondary open angle glaucoma.

Material and methods
This retrospective analysis included 36 pseudophakic eyes (14 eyes with primary open angle glaucoma and 22 eyes with secondary open angle glaucoma) after glaucoma surgery with the EX-PRESS type P-50 without mitomycin C. The preoperative and postoperative intraocular pressure (IOP), best corrected distance visual acuity (BCDVA) and topical antiglaucoma medications were evaluated. The postoperative complications and surgical failure were analyzed. The effectiveness of treatment was assessed at the follow-up visit (mean 8.63 months). Surgical success was defined as complete (without antiglaucoma medications) with IOP ≤ 18 mmHg in criterion A and IOP ≤ 14 mmHg in criterion B. Qualified success was determined as the same IOP levels, but with one or two topical antiglaucoma medications.

Results
The mean intraocular pressure was 29.98 mmHg (SD = 10.85) before surgery and 13.67 mmHg (SD = 6.19) at the follow-up visit (p < 0.05). The complete success rate was 55.56% in criterion A and 44.44% in criterion B. The qualified success rate was 25.00% in criterion A and 16.67% in criterion B. No serious postoperative complications were observed.

Conclusions
This study suggests that the EX-PRESS Glaucoma Filtration Device type P-50 reduces the IOP in most pseudophakic eyes with primary or sec-ondary open angle glaucoma, but the reduction is not always sufficient to reach the target IOP. The use of antiglaucoma medications after EX-PRESS implantation is lowered.