ABSTRACT
BACKGROUND: Glaucoma is the leading cause of irreversible blindness. Normal tension glaucoma (NTG) is a subset of open-angle glaucoma, demonstrating glaucomatous optic nerve damage in the absence of raised intraocular pressure (IOP). NTG is more prevalent in Asian populations. While generally slow-progressing, NTG may be associated with significant central visual field loss. In recent years, minimally invasive glaucoma surgery has been added to the armamentarium of glaucoma surgery. This prospective study aims to evaluate 12-month surgical outcomes of combined iStent inject (Glaukos Corporation, Laguna Hills, CA) implantation and phacoemulsification in Asian eyes with NTG. METHODS: This is a prospective, single-centre case series of 30 eyes followed up until 12 months after surgery. Outcome measures included IOP, number of glaucoma medications, best-corrected visual acuity (BCVA) and intra and postoperative complications. RESULTS: Mean age of subjects was 73.1 ± 6.3 years. Majority were ethnic Chinese (n = 27, 90%). Baseline medicated mean IOP was 13.8 ± 2.4 mmHg and mean number of glaucoma medications was 1.3 ± 0.7. Mean Humphrey visual field mean deviation was - 13.7 ± 7.6. The mean IOP reduction at all timepoints from postoperative month (POM) 3 onwards was statistically significant (all P < 0.05), with mean reduction of 1.2 mmHg (95% CI: 0.1-2.2, P = 0.037) by POM12. There was statistically significant reduction in mean number of medications from postoperative day (POD) 1 onwards (all P < 0.05), with mean decrease of 1.0 medication (95% CI: 0.9-1.1, P < 0.001) by POM12. By POM12, 25 (83.3%) eyes were medication-free. Three (10%) eyes had stent occlusion by iris requiring laser iridoplasty. One eye had gross hyphema which resolved on conservative management before POM1. Mean BCVA improved from the baseline 0.3 ± 0.3 logMAR to 0.1 ± 0.1 logMAR postoperatively (P < 0.001). There were no major adverse or sight-threatening events. No eyes required further glaucoma surgery during the 12-month follow-up period. CONCLUSION: Asian eyes with NTG which underwent combined iStent inject implantation and phacoemulsification demonstrated a significant and sustained reduction in IOP and glaucoma medications, up to 12 months postoperatively.
ABSTRACT
PURPOSE: To evaluate the safety and efficacy of the iStent inject device combined with phacoemulsification in Asian eyes with primary open angle glaucoma. METHODS: A retrospective study of combined phacoemulsification and iStent inject surgeries performed in a single institution from July 2017 to August 2019 on patients with co-existing cataracts and primary open angle glaucoma (POAG). Outcome measures included best-corrected visual acuity, intraocular pressure (IOP), number of glaucoma eyedrop medications, and surgical complications. RESULTS: A total of 95 eyes were included. Majority of subjects were male (59, 62.1%) and Chinese (83, 87.4%). Mean age was 74.7 ± 8.7 years. Pre-operatively, mean IOP was 16.2 ± 4.3 mmHg and number of medications was 1.9 ± 0.9. Significant post-operative reduction in mean IOP was observed at all timepoints - post-operative month (POM)1: 3.0 ± 5.6 mmHg reduction (n = 95, p < 0.05); POM3: 1.6 ± 3.8 mmHg (n = 66, p < 0.05); POM6: 1.8 ± 4.7 mmHg (n = 55, p < 0.05); POM12: 1.3 ± 4.2 mmHg (n = 48) (p < 0.05). The number of glaucoma medications was also reduced from a mean of 1.9 ± 0.8 to 0.6 ± 1.0 at POM12 (p < 0.05). Intraoperatively, one case of malignant glaucoma occurred. Post operatively, implant obstruction by iris was observed in two eyes post-operatively requiring iridoplasty. One case of cystoid macular edema and one case of drop in visual acuity due to glaucoma progression was/were also observed. CONCLUSION: Asian eyes undergoing combined phacoemulsification and iStent inject surgery demonstrate a significant and sustained reduction in both IOP and number of glaucoma medications. Overall, there is a good safety profile for iStent inject.
