Three-year analysis of results, safety and progression in patients with open-angle glaucoma or ocular hypertension, undertaking trabecular microsurgery

Aim

To evaluate the efficacy, safety, structural and functional progression following the insertion of iStent inject ® implants in patients with open-angle glaucoma or ocular hypertension at a tertiary-level hospital.

Materials and methods

A retrospective study included 98 eyes (57 males and 41 females) with open-angle glaucoma or ocular hypertension, which underwent iStent inject W® implantation (Glaukos, Corporation, CA) between December 2018 and December 2022. Differences in intraocular pressure (IOP), the number of hypotensive eye drops used, and structural and functional tests were assessed between preoperative values and subsequent reviews during a follow-up period of one (n = 98), two (n = 55), and three years (n = 15) after surgery.

Results

Among the 98 eyes studied, 85% were diagnosed with open-angle glaucoma (50% mild, 32% moderate, and 18% severe) and 15% with ocular hypertension. There was a statistically significant reduction in IOP compared to preoperative values for all visits except the 1-month (p = 0.36) and 3-year (p = 0.39) visits. Visual acuity increased from 0.39 ± 0.25 to 0.72 ± 0.24 (p < 0.01), considering that a significant portion of the interventions included cataract surgery. Before surgery, 66% of the sample used 2 or more hypotensive medications. Post-surgery, the number of hypotensive medications decreased (from 1.88 ± 0.84 to 0.21 ± 0.59 at 3 years) (p < 0.01), with an 88.9% reduction in the number of medications over three years. After surgery, 75% of cases did not require any medication.

Regarding structural and functional tests, thickness of retinal nerve fiber layers (RNFL (p = 0.35), excavation / papilla ratio E/P (p = 0.31), visual function index

(VFI (p = 0.06), and deviation mean (MD (p = 0.06) showed no statistically significant differences post-intervention. However, standard deviation of the pattern (DSM) did exhibit differences, decreasing from 5.46 ± 4.03 dB to 5.34 ± 3.48 dB (p = 0.02).

Conclusion

The results of this study suggest that the iStent inject W® technique constitutes an effective and safe option for tension control and glaucoma treatment.