Purpose:
Glaucoma topical therapy is associated with ocular surface disease (OSD). To examine the relationship between duration and intensity of topical glaucoma therapy and OSD.
Methods:
This was a single-site prospective controlled cross-sectional study of patients on topical glaucoma therapy. Patients on non-glaucoma topical therapy or ocular surgery within 3 years were excluded. Prior to a comprehensive ophthalmic examination, patients completed the OSD Index (OSDI) questionnaire (score 0-100, 0=no symptoms). Corneal and conjunctival lissamine green (LG) staining (Oxford grade 0-V, 0=no stain), and tear break-up time (TBUT) with 5 µL fluorescein were recorded. Duration of topical glaucoma therapy, total number of applied drops, and a drop-year exposure index (drops/wk × therapy duration in yrs) were noted. For each patient, the worse LG staining eye was chosen. If equally severe, 1 eye was randomly chosen.
Results:
35 patients were enrolled (19 glaucoma, 16 control). Glaucoma patients used a mean of 2.1±0.95 bottles of topical medication for mean duration of 243±255 wks (range 2-800). Mean number of applied drops was 7511±11561 drops/eye, and drop-year exposure index was 243±255 drop-yr. Mean OSDI score of glaucoma patients was greater than controls’ (20±9 vs. 4±6, P=0.0000004). Compared to controls, a higher proportion of glaucoma patients had abnormal LG staining (grade>II; 74% vs. 6%, P=0.00009), tear film quality (TUBT<10 sec; 68% vs. 13%, P=0.002), or OSDI score (OSDI>12; 79% vs. 6%, P=0.00002).Mean duration of glaucoma therapy, number of applied drops, and drop-year exposure were greater in patients with abnormal OSDI score, LG staining, or TUBT (Table). OSDI scores were positively correlated with duration of topical therapy (R=0.70), number of applied drops (R=0.63), and drop-year exposure index (R=0.63).
Conclusions:
In this pilot study OSD was more prevalent, by survey and examination, in glaucoma patients using eye drops. The severity of OSD was positively correlated with duration and exposure intensity of topical glaucoma therapy.
Keywords: clinical (human) or epidemiologic studies: risk factor assessment • ocular irritancy/toxicity testing • cornea: tears/tear film/dry eye