Persistence of Glaucoma Therapy and Visual Field Progression.

PURPOSE

To determine the association of visual field (VF) progression with medication persistence in a cohort on glaucoma therapy.

PATIENTS AND METHODS

Pharmacy records were examined over 3 years for patients started on glaucoma monotherapy. A patient was persistent if a prescription was refilled for the same medication 5 reliable VFs within 1-year pretherapy and 6-year posttherapy were included. Progression was analyzed with pointwise linear regression and defined using 2 criteria: (A) ≥ 2 adjacent progressing points (slope P < 0.01) in 1 hemifield; and (B) ≥ 3 progressing points (slope P < 0.01). The mean number and mean slope of progressing points and the mean global slopes were determined.

RESULTS

Of 1206 patient eyes (131 persistent, 1075 nonpersistent), 941 were excluded leaving 175 (47 persistent and 128 nonpersistent) for analysis. The mean follow-up durations were 59.3 ± 10.9 and 58.2 ± 9.7 months (P = 0.07) for persistent and nonpersistent eyes, respectively. Overall, 2/47 (4.3%) and 10/128 (7.8%) eyes progressed among persistent and nonpersistent patients, respectively (P = 0.52) using criterion A and 1/47 (2.1%) and 12/128 (9.4%; P = 0.19) eyes using criterion B. Mean number of progressing points (0.3 ± 0.9 vs. 0.7 ± 1.8; P = 0.17), mean slope of progressing points (-2.2 ± 1.1 vs. -2.8 ± 1.3 dB/y; P = 0.27), and mean global slope (0.7 ± 0.5 vs. -0.1 ± 0.8 dB/y; P = 0.07) were similar for persistent and nonpersistent patients, respectively.

CONCLUSION

There were small but appreciable differences in VF progression rates between persistent and nonpersistent patient eyes on glaucoma drops, but differences were not significant.