Diagnosing dry eye using a blue-free barrier filter

Abstract

Purpose To investigate the benefit of the blue-free barrier filter (BF filter) in diagnosing dry eye. Design Nonrandomized clinical comparison. Methods Fifty-three eyes with Sjögren syndrome (n = 42) or keratoconjunctivitis sicca (n = 11) were enrolled. Fluorescein staining was performed in temporal and nasal conjunctiva, and staining was scored with (BF score) and without the filter (FL score) from 0 to 3. Rose bengal staining was also scored (RB score) similarly. Results With FL scores of 0, 1, or 2, the BF score was significantly higher: 0.85 ± 0.37 ( P = .031), 1.74 ± 0.65 ( P = .001), and 2.65 ± 0.48 ( P = .001), respectively; with a FL score of 3, the BF score was 3 at all sites. The BF score was superior to the FL score in 66.6% of cases when the FL score was 0 and 1 and in 65.2% when the FL score was 2, but not when the FL score was 3. When the RB score was 0, 1, or 2, the BF score was higher: 1.88 ± 0.92, 1.78 ± 0.79, and 2.57 ± 0.50, respectively ( P = .001 for all); when the RB score was 3, the BF score was 2.97 ± 0.16. The BF score was superior to the RB score in 75.5% of cases when the RB score was 0 and 1 and in 57.8% when the FL score was 2, but not in cases with a RB score of 3. Conclusions The BF filter detects damaged conjunctival epithelium stained with fluorescein. Using the filter was beneficial in mild-to-moderate cases, not in severe cases. The BF filter allows diagnosis of dry eye even at the initial stage that is undetectable by conventional observation.