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Lingyan Anderson, Jason D. Marsack, Ayeswarya Ravikumar, Raymond A. Applegate; Accounting for both lower and higher order aberration in objective refraction to improve image and visual quality. Journal of Vision 2013;13(15):P25. doi: 10.1167/13.15.60.
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© ARVO (1962-2015); The Authors (2016-present)
Background: During clinical subjective refraction, sphere, cylinder and axis are adjusted to achieve the best corrected acuity using patient responses. Certain visual quality metrics are highly correlated with acuity, potentially allowing better objective refractions by objectively answering the question “which is better, 1 or 2.”
Purpose: To determine the best objective correction (sphere, cylinder and axis) in the presence of higher order wavefront error (WFE), utilizing a simulation experimental design.
Method: A large number of spherocylindrical conditions were evaluated to find the condition that maximized the visual Strehl (VSX) for cyclopleged WFEs from 1 eye of 10 individuals. The condition that resulted in the largest VSX was selected as the best objective cycloplegic correction. The resulting Zernike coefficients (through the 10th radial order) were used to simulate logMAR charts for each WFE. LogMAR charts were also generated for cycloplegic subjective refractions. Acuity for each condition was determined by having three normal subjects read each chart up to the 5th miss. Subjective and objective acuities were compared.
Result: The objective correction provided better or equal acuity than the subjective cycloplegic correction (p < 0.05). Four out of 10 objective cycloplegic corrections had more than 1 line improvement compared to subjective cycloplegic correction.
Conclusion: The visual Strehl predictions reliably identified objective cycloplegic corrections that are equivalent to or significantly better than the subjective cycloplegic corrections.
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