A comparative analysis of visual outcome predictions using a retinal acuity meter in cataract patients with coexisting glaucoma

Objective: To compare preoperative visual acuity predicted using a Retinal Acuity Meter (RAM) with the actual best-corrected visual acuity (BCVA) one month after cataract surgery in patients with coexisting cataract and glaucoma, and to assess how glaucoma severity, angle status, and cataract grade influence prediction accuracy.

Methods: This prospective observational study included 20 patients aged 50–80 years presenting with cataract and glaucoma at a tertiary care center. Preoperative evaluation included UCVA, BCVA, RAM testing, refraction, IOP, gonioscopy, cup-to-disc ratio (CDR), and cataract grading (NO2–NO3; NS2–NS3). Postoperative BCVA was assessed one month after surgery using Snellen charts. Prediction accuracy was categorized as accurate (no line difference), one-line difference, or partial-line difference.

Results: Among 20 patients with glaucoma undergoing cataract surgery, RAM accurately predicted postoperative visual acuity in 5 patients (25%). A one-line difference between RAM-predicted and postoperative BCVA was observed in 7 patients (35%), while partial-line differences occurred in 8 patients (40%). Accurate predictions were predominantly observed in eyes with open angles, moderate glaucoma (CDR 0.7–0.8), and well-controlled IOP. Prediction discrepancies occurred in both open- and closed-angle glaucoma, including cases of pseudoexfoliation. Overall, mean preoperative BCVA was approximately 6/24, mean RAM-predicted VA approximately 6/9P, and mean postoperative BCVA approximately 6/6P, with an overall difference generally within one line. All glaucoma stages were represented.

Conclusion: The Retinal Acuity Meter provides reliable predictions of postoperative visual outcomes in cataract patients with glaucoma, with most results falling within one Snellen line of actual postoperative vision. Prediction accuracy is highest in open-angle glaucoma with controlled IOP, while angle-closure and pseudoexfoliation glaucoma show slightly reduced predictability. RAM is a useful adjunct for preoperative visual prognosis in glaucomatous eyes.