Nearwork-Induced Changes in Topography, Aberrations, and Thickness of the Human Cornea After Interrupted Reading

Abstract

Recent experiments have suggested transient changes in corneal optics after short durations of reading. This study investigated an interrupted 1-hour period of reading on corneal topography in a sample of young myopic and emmetropic adults. Ten myopic and 9 emmetropic young adult subjects were recruited for the study. They read adult-level text binocularly at 40 cm with approximately 30 degree downward gaze for 1 hour, with distance correction in place. Orbscan II corneal topography was performed at baseline and 5, 15, 30, and 60 minutes after reading during 1 test session to assess for changes in corneal power, aberrations, and thickness. Myopes exhibited greater corneal power and spherical aberration than emmetropes both before and after reading. Increased corneal higher-order aberrations (at baseline only) and thickness (superior position only) were observed in myopes versus emmetropes. Several corneal parameters differed in the myopes after reading as compared with emmetropes. Differences in corneal parameters were smaller in this study than found in earlier studies, perhaps because of the interrupted nature of the task in the former versus the continuous nature in the latter.