Comparison of the therapeutic efficacy and safety of P50 and P200 ex-PRESS miniature glaucoma device implantation for primary open-angle glaucoma

Objective To compare the efficacy and safety of P50 and P200 Ex‐PRESS miniature glaucoma device implantation for primary open‐angle glaucoma (POAG). Methods Totally 32 eyes from 32 POAG patients were performed from May 2016 to December 2018 in Aier eye hospital of Wuhan university. The patients were randomized into 2 groups (P50 and P200) according to randomized digital table, 16 patients in each group were implanted with either P50 or P200 Ex‐PRESS miniature glaucoma device respectively. All patients were followed up for 12 months to compare the intraocular pressure, best corrected visual acuity, success rate and complications. Results In P50 group and P200 group, the postoperative intraocular pressure at 1 week, 1 month, 3 months, 6 months and 12 months were lower than preoperative intraocular pressure, and the differences were statistically significant (all P<0.05). There was no statistically significant difference in intraocular pressure between the two groups at preoperation and 1 week, 1 month, 3 months, 6 months and 12 months postoperation (all P>0.05). The average best corrected visual acuity of the two groups was 4.33 ± 0.26 versus 4.14±0.59 at 12 months postoperation, with slight decrease, but there was no significant difference between preoperation and postoperation (P>0.05). There was no statistically significant difference in average best corrected visual acuity between the two groups at 12 months postoperation (t=1.67, P>0.05). In the two groups, complete success rate of the operation was 100.0% at 1 week, 1 month and 3 months postoperation. Complete success rate of the operation was 87.5% in P50 group versus 93.8% in P200 group at 6 months postoperation, and the difference was no statistically significant (Χ2=0.367 7, P>0.05). Complete success rate of the operation was 75.0% in P50 group versus 87.5% in P200 group at 12 months postoperation, and the difference was no statistically significant (Χ2=0.820 5, P>0.05). Encapsulated bleb occurred in both groups at 12 months postoperation, and 8 eyes in P50 group and 3 eyes in P200 group, the difference was statistally significant (P<0.05). The blebs of 4 eyes in P50 group and 2 eyes in P200 group were revisited by acupuncture separation combined with 5‐Fu injection. Conclusion Ex‐PRESS P50 and P200 miniature glaucoma device implantation can effectively treat POAG, but the incidence of encapsulated bleb in the late period after P200 miniature glaucoma device implantation is low.