Ocular Surface Symptoms, Objective Redness, and Intraocular Pressure After a Switch from Fixed Dorzolamide/Timolol to Netarsudil in Latanoprost-Treated Glaucoma and Ocular Hypertension: A Prospective Real-World Cohort Study

Background and Objectives: Conjunctival hyperemia is common with netarsudil, but redness may not reflect the overall patient experience when treatment burden is reduced. We evaluated ocular surface symptoms, objective redness, tear-film parameters, intraocular pressure (IOP), and treatment preference after a routine-care switch from twice-daily fixed dorzolamide/timolol to once-daily netarsudil 0.02%, while continuing latanoprost. Materials and Methods: This prospective, single-center observational cohort included 30 consecutive adults with primary open-angle glaucoma or ocular hypertension and controlled IOP. Outcomes were assessed at baseline and months 1 and 2. The primary outcome was the Ocular Surface Disease Index (OSDI). Continuous eye-level outcomes were analyzed using mixed-effects models accounting for fellow-eye and repeated-measures correlation; grade ≥ 2 hyperemia was analyzed using participant-clustered logistic regression. Results: Twenty-seven participants (54 eyes) completed evaluable 2-month follow-up. Median OSDI decreased from 7.50 at baseline to 6.25 at month 1 and 5.00 at month 2 (Friedman p = 0.0015). The mean baseline-to-month 2 change was −2.95 points (95% CI, −4.80 to −1.10), and 6/27 participants (22.2%) improved by at least 7 points. Serle grade ≥ 2 hyperemia increased from 7.4% of eyes at baseline to 51.9% at month 1 and 44.4% at month 2. Estimated mean bulbar redness index increased from 1.57 to 2.14 (p < 0.0001), tear meniscus height increased modestly, and non-invasive keratograph break-up time showed no significant longitudinal change. Estimated mean IOP changed from 14.50 to 13.65 mmHg (p = 0.0083), with no eye showing an increase of at least 4 mmHg. Burning improved after multiplicity adjustment, and 17/27 participants with available month-2 preference data (63.0%) preferred netarsudil. Conclusions: The switch was associated with modest OSDI improvement and maintained short-term IOP control despite increased objective redness. Patient preference appeared to reflect factors beyond redness alone.