Ocular Redness Measured with the Keratograph 5M in Patients Using Anti-Glaucoma Eye Drops

Purpose: To examine correlations between ocular redness measured with the new topographer Keratograph 5M and the use of topical anti-glaucoma medication. Methods: A total of 211 eyes of 211 patients with open-angle glaucoma or ocular hypertension on topical medication and 51 eyes of 51 healthy volunteers were recruited over 10 months. Outcome variables were keratograph redness scores (RS): overall, bulbar temporal (BT), bulbar nasal (BN), limbar temporal (LT), and limbar nasal (LN). In each subject, we also recorded the intraocular pressure-lowering eye drops used, daily doses and daily and cumulative preservative concentrations, fluorescein corneal staining score (OXFORD), lower tear meniscus height (Fourier-domain OCT), non-invasive tear film breakup time (Keratograph 5M), and ocular surface disease questionnaire index (OSDI). Results: Higher RS were recorded in the medication than control group (P < 0.01 all scores). Within the medication group, older patients returned greater RS (P < 0.05 all scores). Prostaglandin was a strong predictor of higher scores, except LN RS. A higher OSDI was associated with a higher LN RS (β = 0.007; P < 0.05), while the use of β-blockers was linked to a lower LN RS (β = ?0.225; P < 0.05). The use of ≥3 daily eye drops with preservative gave rise to a higher BN RS and ≥3 daily eye drops to a higher LN RS (β = 0.366, P < 0.01; β = 0.296, P < 0.05, respectively). Conclusion: Keratograph 5M can objectively detect the hyperaemia induced by glaucoma medication. The factors contributing to ocular redness were advanced age, more daily eye drops (nasal sectors), a higher OSDI, and prostaglandin as the medication used.