A Comparative Study of Manual Small Incision Cataract Surgery Versus Phacoemulsification in Glaucoma Patients with Hard Cataract: An 18-Month Follow-Up

Background: Cataracts and glaucoma are prevalent in the elderly, often co-occurring. Cataract surgery in glaucoma patients reduces intraocular pressure (IOP), improves visual acuity (VA), and enhances glaucoma monitoring. Two main surgical techniques exist, phacoemulsification (PE) and manual small-incision cataract surgery (MSICS). Objective: To compare the outcomes of MSICS and PE in Primary open angle glaucoma (POAG) patients with hard cataracts, focusing on postoperative corneal edema, IOP, and corneal endothelial cell density (CECD). Materials and Methods: The present study was a retrospective cohort study that analyzed 80 eyes from 71 POAG patients with hard cataracts, of LOCS III N3, C3, or higher, who underwent either MSICS or PE at Prapokklao Hospital between November 2020 and December 2022. Exclusion criteria included IOP greater than 25 mmHg despite medical treatment, acute angle closure glaucoma, glaucoma secondary to trauma, and other comorbidities. Central corneal thickness (CCT) and CECD were measured pre- and post-operatively at day-1, day-7, month-1, -3, -6, -12, and -18. IOP and glaucoma medication were also tracked. Results: One day postoperatively, CCT increased significantly more in the PE group, at 53 μm, than in the MSICS group, at 40 μm (p=0.022). However, both groups returned to near preoperative CCT levels by one month. Both surgical methods significantly reduced IOP at 1, 3, and 12 months postoperatively, but the reduction was significantly greater in the MSICS group at 1 month (p<0.001). VA significantly improved in both groups at 3 months postoperatively. CECD decreased in both groups at 18 months, but the difference was not statistically significant (p=0.058). At 6 and 18 months, significantly more patients in the MSICS group used only one glaucoma medication (p=0.009, 0.015). Conclusion: PE resulted in a significantly greater increase in CCT one day postoperatively compared to MSICS. Long-term changes in CECD were not significantly different between the groups. Both surgical methods resulted in significant IOP reduction at 1 month postoperatively, with MSICS showing a greater reduction.