Purpose
To determine the intraocular pressure-lowering effect and safety of opening the Gold Micro Shunt’s (GMS) windows.
Methods
The study is a case series that studied 5 subjects, among which there were three with primary open-angle glaucoma, one with aphakic glaucoma and one with neovascular glaucoma. It looks retrospectively at the safety of opening the GMS’ windows and its effect on the IOP and number of glaucoma eyedrops. Among the research subjects, there were 4 males and 1 female, aged between 56 and 81 (average age 70). Four of the subjects were Caucasian and one was Hispanic. They had undergone 0 to 4 surgeries before GMS implantation. The GMS has 8 closed windows upon implantation. Four of these windows were opened in all five patients. Average follow-up post GMS implantation was 3 years. The GMS was implanted in each patient. The IOP (using a Goldmann tonometer) and number of glaucoma medications were recorded before and after the implantation of the GMS, as well as before and after the opening of the GMS’ windows with a Titanium-Sapphire (Ti-Sap) laser. Patients were assessed for complications arising from implanting the GMS and opening its windows.
Results
Implantation of the GMS was associated with an average decrease in IOP of 37.0% (p=0.076). The average IOP before window-opening was 24.9 and after window opening, it was 17.6 .The IOP thus dropped a further 29.3% (p=0.055) on average after the opening of the GMS’ windows. The windows were opened an average 6.4 months after GMS implantation. IOP dropped 2.3 to 10.7% per window opened (average 7.3%). Long-term IOP at follow-ups remained lower than pre-GMS levels in all patients. The IOP reduction post window opening lasted throughout follow-up, i.e. from 17 to 42 months (average 30 months). The number of glaucoma drops for each patient did not decrease after opening the GMS’ windows. One patient developed transitory cystoid macular edema after GMS implantation that resolved with a course of NSAID drops. No complication arose from the opening of the GMS’ windows.
Conclusions
Our study suggests that opening the GMS’ windows is safe and is associated with a substantial and sustained reduction in IOP. In the future, conducting similar studies with larger cohorts and longer follow-up would make it possible to obtain more data.
Keywords: 568 intraocular pressure •
578 laser •
420 anterior chamber