Abstract
Purpose :
To determine the one-year surgical outcomes of trabecular meshwork microstent placement for eyes with severe glaucoma
Methods :
The retrospective cohort study included patients with a diagnosis code of severe stage glaucoma before trabecular meshwork (TM) microstent placement from 1/2014 to 6/ 2021. Patients with at least 6-months follow-up in the post-operative period were included. Demographic and clinical data were collected at the preoperative visit and post-operative visits for up to 1 year. Surgical failures were defined as eyes that required further glaucoma surgeries or progressed to no light perception.
Results :
40 eyes of 36 patients were included. Mean age was 74.9±7.5 years old. 37 (93%) eyes had iStent and 3 (7%) had Hydrus. 23 (58%) eyes had 1 microstent (first generation iStent or Hydrus) placed, 16 (40%) had 2 microstents (iStent inject), and 1 (2%) had 3 stents (iStent infinite). All (100%) microstents were placed in combination with cataract surgery. At the preoperative (pre-op) visit, Humphrey 24-2 visual field (VF) mean deviation was -9.2±8.1 dB (n=12), Octopus 30-2 GTOP VF mean defect was 13.5±8.8 dB (n=26), and mean cup-to-disc ratio was 0.8±0.2. Mean pre-op intraocular pressure (IOP) was 15.9±5.1 mmHg and mean number of pre-op medications was 2.6±1.2. Post-operative (post-op) mean IOP overall ranged from 13.8±3.9 to 16.7±7.2 mmHg and were only different at 3- and 6-month visits (p<0.05 for both). Mean number of glaucoma drops at the 6- and 12-month visits of 1.6±1.2 and 1.8±1.5 drops, respectively were also lower than baseline (p<0.05 for both). Within 3 months post-op, 1 (2.5%) eye developed IOP less than 5 mmHg without hypotony related complications and 16 (40%) eyes developed elevated IOP: 14 (35%) greater than 20 mmHg and 2 (5%) greater than 30 mmHg. There was no difference in drop regimen at 6- and 12-months comparing the use of 1 versus 2 microstents (p>0.2 for both). Within the first post-op month, 3 (7.5%), 18 (45%), and 4 (4.5%) eyes developed microhyphema, mild iritis (1+ cell and/or flare or worse), and corneal edema, respectively. 2 patients required further glaucoma surgery with 1 Xen gel stent and 1 Ahmed tube shunt.
Conclusions :
Although not approved by insurance for severe glaucoma, any microstent placement demonstrated a possible benefit of decreasing medication burden for patient for up to 12 months with low surgical risk when combined with cataract surgery.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.