PURPOSE: To investigate the relationship between higher order aberrations and low contrast visual acuity in myopic eyes under mesopic conditions. METHODS: This prospective, observational case series included 52 patients (29 women, 23 men) aged 18 to 35 years. Ocular higher order aberration was measured under mesopic conditions using the Hartmann-Shack wavefront analyzer, and high (100%) and low contrast (5%, 10%, and 25%) visual acuity was measured using a multi-function visual acuity tester under the same conditions. RESULTS: Multiple linear regression analysis revealed that spherical aberrations were significantly associated with low contrast visual acuity at a low contrast level. The correlation coefficients of spherical-like aberration (S(4)) were 0.393, 0.315, and 0.419 at 5%, 10%, and 25%, respectively (P=.004, .023, and .002, respectively). The correlation coefficient of spherical aberration ( C40) was 0.373 at the 5% contrast visual acuity level (P=.006). However, coma and other higher order aberrations did not correlate statistically (P>.05). CONCLUSIONS: Relationships exist between S(4) and C40 and low contrast visual acuity. Effects on low contrast visual acuity increase with the value of spherical aberration. This suggests that less spherical aberration may provide optimal visual function under night conditions. Copyright 2011, SLACK Incorporated.
PURPOSE: To investigate the relationship between higher order aberrations and low contrast visual acuity in myopic eyes under mesopic conditions. METHODS: This prospective, observational case series included 52 patients (29 women, 23 men) aged 18 to 35 years. Ocular higher order aberration was measured under mesopic conditions using the Hartmann-Shack wavefront analyzer, and high (100%) and low contrast (5%, 10%, and 25%) visual acuity was measured using a multi-function visual acuity tester under the same conditions. RESULTS: Multiple linear regression analysis revealed that spherical aberrations were significantly associated with low contrast visual acuity at a low contrast level. The correlation coefficients of spherical-like aberration (S(4)) were 0.393, 0.315, and 0.419 at 5%, 10%, and 25%, respectively (P=.004, .023, and .002, respectively). The correlation coefficient of spherical aberration ( C40) was 0.373 at the 5% contrast visual acuity level (P=.006). However, coma and other higher order aberrations did not correlate statistically (P>.05). CONCLUSIONS: Relationships exist between S(4) and C40 and low contrast visual acuity. Effects on low contrast visual acuity increase with the value of spherical aberration. This suggests that less spherical aberration may provide optimal visual function under night conditions. Copyright 2011, SLACK Incorporated.