Fixed versus Unfixed Combination of Topical Latanoprost/Timolol for Glaucoma: An Observational Study Investigating the Level of Adherence and Ocular Surface Health

To investigate the effect of fixed combination versus concomitant unfixed topical glaucoma treatment on patients' adherence and ocular surface health. This is a 6-month, prospective, parallel-group, observational study in patients with ocular hypertension (OHT), primary open-angle glaucoma (POAG), or exfoliation glaucoma (XFG). A total of 142 patients with similar baseline characteristics were enrolled in this study. Seventy-one patients received a Latanoprost 0.005%/Timolol 0.5% fixed combination in the evening, whereas seventy-one patients received the unfixed treatment with Latanoprost 0.005% in the evening and Timolol 0.5% twice daily. The primary outcome was the adherence rate at baseline, and at the 3- and 6-month follow-up visits. The secondary outcomes included the signs of ocular surface disease (OSD) and intraocular pressure (IOP). The adherence of patients treated with the fixed combination was higher than the unfixed treatment at the 3-month (78.0% vs. 63.0%, < 0.001) and at the 6-month visits (73.0% vs. 58.5%, < 0.01). The Break-up Time, Schirmer test, and Van Bijsterveld score were worse in the unfixed group at baseline and all subsequent examinations ( < 0.05 for all comparisons). There were no differences in the mean IOP between groups at baseline, 1-, and 3-month visits. IOP appears higher in the unfixed group at 6 months (16.7 vs. 15.0 mmHg, < 0.01). The patients with ocular hypertension and primary open-angle glaucoma treated with a fixed combination are significantly more adherent and show a healthier ocular surface than those treated with an unfixed combination. The study provides significant evidence of the benefits of fixed combination treatment.