Research Lecture Series
Dr. Atanu Ghosh, Ph.D of the University of Rochester School Of Medicine, Rochester, NY will present a lecture on “Optical and Biomechanical Factors Associated with Near Work and Myopia” at the New England College of Optometry on Tuesday, February 24, 2015.
Near work may play an important role in the development of myopia in the younger population. The prevalence of myopia has also been found to be higher in occupations that involve substantial near work tasks, for example in microscopists and textile workers. When nearwork is performed, it typically involves accommodation, convergence and downward gaze. A number of previous studies have examined the effects of accommodation and convergence on changes in the optics and biometrics of the eye in primary gaze. However, little is known about the influence of accommodation on the eye in downward gaze. To achieve this we modified a Shack-Hartmann aberrometer and Lenstar optical biometer to measure wavefront aberrations and ocular biometrics in downward gaze with accommodation under binocular fixation. The longitudinal spherical aberration was significantly more negative in myopes (–1.08 ± 0.86 D) than emmetropes (–0.25 ± 0.73 D) after 10 minutes of the 5 D accommodation task (p<0.05) with natural pupils. Myopes also exhibited significantly greater levels of HORMS than emmetropes during the task (after 10 minutes) with the higher level of accommodation (5D) (mean difference of 0.14 ± 0.09 D, p<0.05). There was a significant influence of gaze angle on axial length, with the greatest axial elongation (+18 ± 8 μm) occurring with infero-nasal gaze and a slight decrease in axial length in superior gaze (−12 ± 17 μm) compared with primary gaze. There was a significant correlation between refractive error (spherical equivalent refraction) and the mean change in axial length in the infero-nasal gaze direction (Pearson’s R2 = 0.71, p <0.001). The findings of these experiments collectively show the dynamic characteristics of the optics and biometrics of the eye in downward gaze during a near task, over time. These were small but significant differences between myopic and emmetropic eyes in both the optical and biomechanical changes associated with shifts of gaze direction. These differences between myopes and emmetropes could arise as a consequence of excessive eye growth associated with myopia. However the potentially additive effects of repeated or long lasting near work activities employing infero-nasal gaze could also act to promote elongation of the eye due to optical and/or biomechanical stimuli.
All are welcome to attend. One hour of Mass C.E. credit will be awarded. Please join us for a reception in Conference Room 1 following the lecture. Wine and light fare will be served.
For more information, please contact Leah Boudreau, 617-587-5628. No RSVP is necessary.