Abstract
Purpose: :
Reduced visual performance is a major symptom reported by patients with dry eye disease (DED). Previous survey studies have suggested that dry eye patients report having reading difficulties. Dry eye patients also exhibit reduced visual performance on tests that require rapid visual integration. Since reading requires the coordination of saccades and brief fixations for visual integration, the purpose of this study was to evaluate visual performance including reading speed and contrast sensitivity in normal and dry eye subjects.
Methods: :
Seventy-two subjects (normal = 20, mild dry eye = 17, moderate dry eye = 22, severe dry eye = 13) took part in this study. The dry eye subjects had OSDI scores ≥ 20 and were stratified into mild, moderate or severe groups based on corneal fluorescein staining. Contrast sensitivity was measured with the HACSS by M&S Technologies and reading speed was determined with the Wilkins Rate of Reading test. Differences between groups were evaluated with an ANCOVA. Partial correlations were determined between contrast sensitivity, reading speed and other clinical measures of dry eye disease.
Results: :
The logMAR visual acuities were not significantly different between the normal and dry eye subjects. The contrast sensitivity data were not significantly different across subject groups for any spatial frequency or for the area under the contrast sensitivity curve (AUC). The dry eye subjects exhibited slower reading speeds (134.9 ± 4.95 words/minute) than the normal subjects (158.3 ± 8.4 words/minute, p = 0.046). As dry eye severity increased, the reading speed decreased (141.0 ± 7.96, 136.8 ± 7.15, and 127.0 ± 9.63 words/minute, in mild, moderate, and severe DED groups, respectively). The highest correlation (-0.345, p < 0.001) was found between reading speed and corneal staining.
Conclusions: :
The reading speed was lower in DED patients than normal control subjects. As the dry eye severity increased, the reading rate decreased. This is consistent with patient reported symptoms and provides direct evidence for the impact of DED on reading performance. These results suggest that reading speed may be used to monitor treatment in DED patients.
Keywords: reading • contrast sensitivity