Effect of glaucoma on identification of bottle cap color in ophthalmic medications

A prospective, nonrandomized, observational trial of 60 glaucoma patients to correlate visual acuity and visual field with ability to distinguish bottle cap color of commonly used ophthalmic medications was conducted. A total of 103 eyes from 60 patients (30 women) were evaluated. The mean logMAR acuity was 0.34±0.54 (approximately 20/45 Snellen acuity), average Humphrey Visual Field (HVF) mean deviation was -8.58±8.69 dB, mean Ishihara plates (out of 14) were 11.78±4.15, and bottle cap color score (out of 10) was 8.56±2.51. Multiple linear regression analysis revealed an independent correlation of visual acuity (P=0.0137) and Ishihara score (P0.05). Glaucoma patients with poor visual acuity, but not necessarily advanced visual field loss, are likely to have difficultly identifying the color of their bottle caps. Physicians should be cognizant of this potential issue when reviewing medications with patients.