Abstract
Purpose: :
Dry eye patients frequently report visual difficulty, especially when reading for long durations or performing other near tasks . Here we, compare reading speeds in dry eye patients and individuals without symptomatic dry eye using two novel reading tests.
Methods: :
Subjects with clinical and symptomatic dry eye followed at the Wilmer Eye Institute Ocular Surface Disease clinic were compared to a group of control subjects with normal vision and no dry eye symptoms. All patients were over the age of 50. Out-loud reading was evaluated using a 75-word International Reading Speed Text (IREST) passage, while prolonged silent reading was evaluated over 30 minutes using a 7,200-word standardized passage. Silent reading speed was calculated from the timing of page turns. Multiple choice questions were asked at the end of the sustained silent reading passage to confirm that the subjects read the passage with attention. Severity of dry eye symptoms was evaluated using the Ocular Surface Disease Index (OSDI), with scores reported on a scale of 0 to 100.
Results: :
Seventy-two subjects completed the study, including 51 control and 21 dry eye subjects. Dry eye subjects did not differ from control subjects with regards to age, race, gender, level of education, or visual acuity (p > 0.08 for all). Out loud reading was slower in dry eye subjects as compared to controls (149 vs. 164 wpm, p=0.02), as was silent reading speed over the 30 minute silent reading interval (186 vs. 226 wpm, p=0.02). In multivariable linear regression models adjusting for age, race, gender and education, out loud reading speed was 17 words/minute slower amongst dry eye subjects, while sustained silent reading speed was 45 words/minute slower amongst dry eye subjects. Severity of dry eye symptoms was associated with slower reading speeds, with each 5 point drop is OSDI score associated with a 4 wpm decrease in silent reading speed (p=0.004).
Conclusions: :
Patients with symptomatic dry eye read significantly slower than subjects without dry eye symptoms and greater decreases in reading speed are found with more severe dry eye symptoms. The full impact of dry eye on reading may be better captured with tests of sustained silent reading than standard out loud reading tests that use brief texts. Further research is warranted to determine the impact of dry eye, and dry eye treatments, on reading performance and workplace productivity.
Keywords: reading • cornea: tears/tear film/dry eye