Comparative analysis of ocular redness score evaluated automatically in glaucoma patients under different topical medications

Purpose: To compare ocular redness score calculated automatically between glaucoma patients and healthy controls, and to assess the associations between this score and both demographical and clinical characteristics. Methods: Glaucoma patients under different topical medications and matched controls were enrolled in this observational cross-sectional study. The Keratograph 5M (Oculus Optikgeräte GmbH) was used to automatically measure 5 redness scores: global; nasal bulbar; temporal bulbar; nasal limbal; temporal limbal. The Student t and ANOVA tests were used to compare continuous variables between groups. A multiple linear regression analysis was performed to evaluate the associations between redness scores and the use of different active principles. Results: One hundred two glaucoma patients and 32 controls were included. Ocular redness scores were significantly higher in glaucoma patients compared to controls (always p < 0.001). The number of active principles was significantly associated with all the redness scores (always p < 0.05). The use of carbonic anhydrase inhibitors (CAIs) was the strongest predictor of overall redness, followed by prostaglandin analogs (PAs) and alpha-adrenergic agonists (AAAs) (respectively, β = 0.400, p = 0.002; β = 0.330, p = 0.013; β = 0.311, p = 0.044). The post hoc analysis measuring the effect of different PAs on redness scores showed that overall redness and bulbar nasal redness scores were significantly lower in patients using tafluprost and latanoprost compared to those using travoprost and bimatoprost 0.01% (respectively, p = 0.025 and p = 0.024). Conclusion: Ocular redness was significantly higher in patients with glaucoma compared to control subjects. The number of active principles and the use of PAs, CAIs and AAAs were associated with higher redness scores.