Outcome of a single XEN microstent implant for glaucoma patients with different types of glaucoma

Abstract

Background: The aim of this retrospective study was to compare the efficacy and safety profile of a single XEN-microstent in different types of primary and secondary open angle glaucoma.

Methods: A single XEN microstent was implanted in patients with primary open-angle glaucoma (POAG), normal-tension glaucoma (NTG), pseudoexfoliation glaucoma (PEX) and secondary glaucoma (Sec.Gl). The intraocular pressure (IOP), the active substances of the applied IOP-lowering drugs, the best corrected visual acuity (BCVA) and the mean deviation (MD) of the perimetry were measured at baseline and at regular follow-ups, scheduled at 2 days and 1, 3, 6 and 12 months after surgery.

Results: 153 eyes were included in this analysis. 113 eyes were affected by POAG (74%), 5 eyes by NTG (3%), 22 eyes by PEX (14%) and 13 eyes by Sec. Gl (9%). Mean IOP decreased in all treatment groups during the 12 months of follow-up (complete group: 23.9 ± 7.4 to 15.4 ± 5.1 mmHg (p < 0.01); POAG: 22.8 ± 6.5 to 15.1 ± 4.6 mmHg (p < 0.01); NTG: 16.6 ± 3.4 to 11.6 ± 2.2 mmHg (p < 0.05); PEX: 28.0 ± 7.9 to 17.1 ± 6.6 mmHg (p < 0.01); Sec.Gl: 28.9 ± 13.9 to 15.5 ± 6.9 mmHg (p < 0.05)). In the 153 eyes the average number of IOP-lowering drugs applied decreased from 2.6 ± 1.2 to 0.8 ± 1.3 12 months after surgery (p < 0.01). BCVA and mean deviation of automated standard perimetry remained stable in all groups during follow-up.

Conclusion: As in eyes suffering from POAG, IOP and number of IOP-lowering drugs applied can be effectively reduced by XEN implantation in eyes suffering from NTG, PEX and secondary glaucoma while leaving BCVA and visual field unchanged.

Trial registration: Trial was registered at DRKS (registration number: DRKS00020800 , Registered 25.February 2020 - Retrospectively registered).

Keywords: MIGS; Primary open-angle Glaucoma; Trabeculectomy; XEN.

Fig. 1

Mean IOP over study time. Course of mean IOP (in mmHg) for the whole group (a) as well as the subgroups (b) according to glaucoma type, i.e. primary open angle glaucoma (POAG), normal pressure glaucoma (NTG), pseudoexfoliation glaucoma (PEX) and secondary glaucoma of different etiology (see eq.)

Fig. 2

Pre- and postoperative IOP in different groups of glaucoma. Scattergram of pre- and 12-month postoperative IOP (in mmHg) in the four subgroups of glaucoma treated with XEN-microstent-implantation in (a) primary open angle glaucoma, (b) normal pressure glaucoma, (c) pseudoexfoliation glaucoma, (d) secondary glaucoma. The 21 mmHg-value is highlighted with a horizontal line to recognize the proportion of cases with an IOP below or above 21 mmHg 12 months after surgery

Fig. 3

IOP-lowering agents over study time. Progression of the number of mean IOP-lowering agents (number) used in the entire XEN Microstent patient group and in the subgroups depending on glaucoma type during the first 12 months of postoperative follow-up. (primary open angle glaucoma (POAG); normal pressure glaucoma (NTG); pseudoexfoliation glaucoma (PEX); secondary glaucoma (sec. Gl))

Fig. 4

Visual acuity over study time in different groups of glaucoma. Course of BCVA in the entire group of eyes treated with XEN microstent implantation and in subgroups depending on the type of glaucoma in the first 12 months of postoperative follow-up.(primary open angle glaucoma (POAG); normal pressure glaucoma (NTG); pseudoexfoliation glaucoma (PEX); secondary glaucoma (sec. Gl))