The in-office techniques of ocular surface evaluation don't reflect real-world experiences and may miss some dry eye cases, a new study finds. Researchers recently reported findings after evaluating 177 patients with dry eye and 34 normal controls before and after reading silently for 30 minutes—and the results are enlightening.

Using the Ocular Surface Disease Index (OSDI) questionnaire in conjunction with automated noninvasive tear break-up time (TBUT), surface asymmetry and regularity indices, Schirmer’s testing without anesthesia, fluorescein corneal staining and lissamine green conjunctival staining, the investigators realized reading for 30 minutes led to worsening in all parameters, with the exception of surface asymmetry index, in both dry eye patients and controls. The data also showed the more unstable the tear film was at baseline, the worse it got after the reading task, suggesting dry eye patients are more affected by visually taxing tasks such as reading.

“Evaluating tear film and ocular surface parameters at rest may miss clinical findings brought about by common everyday tasks such as reading, leading to discordance between patient-reported symptoms and clinician-observed signs,” the researchers concluded. “Quantifying dry eye after visually straining activities such as prolonged silent reading may help better understand patient symptomatology.”

Karakus S, Agrawal D, Hindman HB, et al. Effects of prolonged reading on dry eye. Ophthalmology. April 25, 2018. [Epub ahead of print].