Background: Olopatadine hydrochloride 0.1% eye drops represent a new class of anti-allergic agent with combined antihistaminic and mast cell-stabilizing properties.
Objective: The purpose of this study was to describe alterations in tear function and the ocular surface in patients with allergic conjunctivitis and to analyze the effect of topical olopatadine treatment on corneal sensitivity, tear function, and impression cytology variables.
Methods: This was a single-center, 3-visit, prospective, open-label study conducted in patients with allergic conjunctivitis. Patients received 1 drop of topical olopatadine hydrochloride 0.1% BID for 3 weeks. At each visit, patients and healthy control subjects underwent routine ophthalmic examinations and measurements of corneal sensitivity and tear function (Schirmer test of tear quantity, tear film break-up time [BUT], fluorescein staining of the cornea). All control subjects and a subgroup of patients also underwent conjunctival impression cytology for assessment of squamous metaplasia and goblet cell density. The outcomes of interest were changes in corneal sensitivity, tear function, and impression cytology variables after 3 weeks of treatment with olopatadine eye drops, both in patients with allergic conjunctivitis and between patients and controls.
Results: At enrollment, the study included 46 eyes of 23 patients (9 men, 14 women; age range, 20-42 years) with allergic conjunctivitis; results were calculated based on the 21 patients who completed the study. The control group consisted of 70 eyes of 35 healthy subjects (13 men, 22 women; age range, 22-39 years). Before treatment, 64.3% of the eyes of patients with allergic conjunctivitis had a fluorescein staining score of >1 point, whereas after treatment, 14.3% had a score of >1 point (P < 0.001). Patients' mean (+/- SD) corneal sensitivity improved to 55.0 +/- 2.5 mm from the pretreatment value of 42.5 +/- 2.5 mm (P < 0.001). Mean BUT values before and after treatment were 8.1 +/- 3.5 and 14.0 +/- 7.0 seconds, respectively (P < 0.001). Before treatment, patients' mean squamous metaplasia grade was 2.5 +/- 0.5; at the end of treatment, it had decreased to 1.0 +/- 0.5 (P < 0.001). The mean pretreatment goblet cell density of 545 +/- 85 cells/mm2 improved to 1,090 +/- 100 cells/mm2 after treatment (P < 0.001).
Conclusion: In the patient population studied, the disorder of tear function, squamous metaplasia, and loss of ocular surface goblet cells associated with allergic conjunctivitis improved with topical olopatadine treatment.