Purpose:
Glaucoma topical therapy is associated with ocular surface disease (OSD). To examine the temporal correlation between OSD symptoms and the duration and intensity of topical glaucoma therapy.
Methods:
This was a prospective controlled cross-sectional study. Patients on non-glaucoma topical therapy, ocular surgery within 3 years, and diagnosis of OSD were excluded. 62 patients were enrolled (32 on topical therapy, 30 controls). The Ocular Surface Disease Index (OSDI) questionnaire (score 0-100, 0=no symptoms, 100=maximum symptoms) was administered for each patient. Main outcome measures were OSDI scores, duration of topical therapy, total number of applied drops, and a drop-year exposure index (drops/week × therapy duration in yrs). For each patient, the eye with longer therapy duration was chosen. In patients with equally treated eyes, one eye was randomly selected.
Results:
Glaucoma patients used a mean of 2.1±0.88 topical medications for mean duration of 222±215 weeks (range 2-800). The mean number of applied drops was 6001±9174 drops/eye. The mean exposure index was 115 ±176 drop-year. Mean OSDI score of glaucoma patients (18.5±9.5) was greater than controls’ (6.3±5.7, P= 0.0000001). More glaucoma patients (n=22, 69%) than controls (n= 5, 17%) reported OSD symptoms (OSDI score>12, P= 0.00003). In the topical glaucoma therapy group, those with OSD symptoms had a longer mean duration of therapy, a greater number of applied drops, and a higher exposure index (Table). OSDI scores were positively correlated with the duration of topical therapy (R=0.6), total number of applied drops (R=0.49), and the exposure index (R=0.49).
Conclusions:
OSD symptoms were more prevalent in patients on topical glaucoma therapy. The severity of OSD symptoms was positively correlated with the duration and exposure intensity of topical glaucoma therapy. Patients on topical therapy for mean duration of 18 months or less did not exhibit significant OSD symptoms.
Keywords: clinical (human) or epidemiologic studies: prevalence/incidence • ocular irritants • drug toxicity/drug effects