WHEN PUPIL DIAMETER MATTERS: A MODEL OF THE INFLUENCE OF PHYSIOLOGICAL PUPIL DIAMETER ON WFE FOLLOWING REFRACTIVE SURGERY

Title WHEN PUPIL DIAMETER MATTERS: A MODEL OF THE INFLUENCE OF PHYSIOLOGICAL PUPIL DIAMETER ON WFE FOLLOWING REFRACTIVE SURGERY
Author, Co-Author Michelle Koe, Raymond Applegate, Adrian Glasser, Katrina Parker, Jason Marsack
Topic
Year
2007
Day
Wednesday
Program Number
075082
Room
Affiliation
University of Houston, College of Optometry
Abstract PURPOSE: To model the effect of large inter-subject variance in pupil response to luminance on post wavefront guided refractive surgery wavefront error (WFE).

METHODS: Pupil diameter was measured at various luminance levels (200, 23.2, 2.5, 0.34, 0.036 cd/m2) for 10 subjects. Each subject’s data was well fit with a linear equation. Three of these functions were selected to represent typical extremes in inter-subject variation: a) high y-intercept (7.0 mm) with a steep slope (-0.49 mm/log cd/m2), b) high y-intercept (6.8) with a shallow slope (-0.16), and c) low y-intercept (4.3) with an average slope (-0.25). Two luminance levels (0.4 and 200 cd/m2) were selected to model the pupil diameter that would occur for the 3 functions. Dilated wavefront error (WFE) measurements over a 7.5 mm pupil were obtained through the 10th radial order for 3 postoperative refractive surgery eyes: high amount of postoperative HO RMS WFE (1.9 μm), median amount (1.7 μm) and a low amount (0.7 μm). The WFEs of these subjects were then recalculated for the pupil diameters associated with each of the 3 selected pupil versus log luminance functions (a, b,& c).

RESULTS: When sorted by HO RMS WFE (lowest to highest), the lowest WFEs were obtained using the function with the average slope and the low y-intercept (c). The calculations for the function with a shallow slope and a high y-intercept (b) produced the largest HO RMS WFEs. The eye with high HO RMS WFE sorted to the bottom regardless of the physiological pupil response to luminance.

CONCLUSIONS: Retinal image quality is influenced by an individual’s aberration structure as well as his/her physiologic pupil response to luminance. The relative change in aberrations from pre- to postoperative states should be considered in conjunction with physiological pupil responses in future work with this model.
Affiliation of Co-Authors University of Houston, College of Optometry, University of Houston, College of Optometry, University of Houston, College of Optometry, University of Houston, College of Optometry
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