Effect of Preoperative Trabecular Meshwork Pigmentation and Other Eye Characteristics on Outcomes of Combined Phacoemulsification/Minimally Invasive Glaucoma Surgery

Purpose

To investigate associations between pigmentation of the trabecular meshwork (PTM) and other preoperative eye characteristics and outcomes of minimally invasive glaucoma surgery combined with phacoemulsification (Phaco/MIGS).

Design

Retrospective interventional case series.

Participants

Academic glaucoma clinic patients with symptomatic cataract and glaucoma treated with combined Phaco/MIGS.

Methods

Analyzing preoperative PTM, intraocular pressure (IOP), IOP-lowering medications and visual acuity (VA) data in relation to Phaco/MIGS outcomes.

Main Outcome Measures

Pigmentation of the trabecular meshwork and other preoperative eye characteristics in relation to Phaco/MIGS success defined as postoperative IOP between 5 and 21 mmHg and IOP reduction of ≥ 20% and/or a reduction of ≥ 1 IOP-medications compared to baseline, and final IOP, IOP-lowering medications and VA.

Results

A total of 265 eyes (172 patients, mean age, 73.5 [standard deviation, 10.0], range 35–95 years, male 40.0%) were identified and categorized with high PTM (108 eyes, 40.8%) or low PTM (157 eyes, 59.2%). The high PTM group, compared with the low PTM group, demonstrated higher preoperative IOP (16.7 [standard error 0.4] vs. 15.2 [0.4] mmHg, P = 0.009), included more eyes with primary open-angle glaucoma (POAG, P = 0.03), fewer eyes with normal-tension glaucoma (NTG, P = 0.01), and fewer eyes with mild stage glaucoma (P = 0.001). Compared to baseline, final IOP decreased by 6.5 [2.4]% and 13.4 [3.0]% (P = 0.075) to 13.5 [0.3] mmHg and 13.6 [0.4] mmHg (P = 0.77) in the low and high PTM groups, respectively, and IOP-lowering medications decreased by 34.6 [4.9]% (n = 116) and 18.1 [7.3]% (n = 85), respectively (P = 0.062). Surgical success was 59.9% and 58.3%, respectively (P = 0.87). It was positively associated with higher preoperative IOP (hazard ratio 1.08 [95% confidence interval 1.04–1.12] P < 0.0001) and higher number of preoperative IOP-medications (1.20 [1.05–1.37] P = 0.007), negatively associated with history of selective laser trabeculoplasty (SLT, 0.40 [0.23–0.68] P = 0.0009) and longer axial length (0.87 [0.80–0.94], P = 0.0006), but was not associated with PTM.

Conclusions

Higher PTM was associated with POAG rather than NTG, with more severe glaucoma and higher preoperative IOP, but not with Phaco/MIGS success. Surgical success was positively associated with higher preoperative IOP and number of IOP-medications and negatively associated with history of SLT and longer axial length. These findings may help guide glaucoma surgeons in surgical planning and patient counseling.

Financial Disclosure(s)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.