Asaki Suzaki

Characteristics of ocular higher-order aberrations in patients with pellucid marginal corneal degeneration.

PURPOSE: To evaluate the characteristics of higher‐order aberrations (HOAs) in eyes with pellucid marginal corneal degeneration (PMCD). SETTING: Department of Ophthalmology, Osaka University Medical School, Osaka, Japan. METHODS: Ocular HOAs were measured by aberrometry in 20 eyes with PMCD (PMCD group), 76 eyes with keratoconus (KC group), and 105 normal eyes (control group) with a 4.0 mm pupil. The magnitudes and axes of trefoil, coma, tetrafoil, and secondary astigmatism and the magnitude of spherical aberration were compared between the 3 groups using vector analysis of Zernike terms. RESULTS: The mean axes of coma in the PMCD group (85.5 degrees) and KC group (82.5 degrees) were opposite the axis in the control group (253.7 degrees). The magnitude of coma was significantly lower in the PMCD group (0.27 μm ± 0.19 [SD]) than in the KC group (0.70 ± 0.37 μm) (P<.05). The mean axes of trefoil in the PMCD group (27.1 degrees) and control group (35.4 degrees) were opposite the axis in the KC group (93.8 degrees). The magnitude of spherical aberration was significantly higher in the PMCD group (0.086 ± 0.10 μm) than in the KC group (−0.030 ± 0.13 μm) (P<.05); the spherical aberration signs were opposite in the groups. CONCLUSIONS: Although PMCD and KC are categorized as noninflammatory corneal thinning disorders, the HOA patterns in the 2 groups differed, possibly due to differences in the positions of the corneal apex. PMCD and KC may cause distinctively different deterioration in the quality of vision.

Effect of low-addition soft contact lenses with decentered optical design on myopia progression in children: a pilot study.

Purpose To investigate the effect of low-addition soft contact lenses (CLs) with decentered optical design on the progression of myopia in children in a pilot study. Subjects and methods Twenty-four Japanese children age 10–16 years with baseline myopia of −0.75 to −3.50 D sphere and ≤1.00 D cylinder were studied. The new CLs were designed to have a nasal decentration with the optical center centered on the line of sight, and with progressive-addition power of +0.5 D peripherally. Monofocal soft CLs were used as controls. A pair of new CLs or control CLs was randomly assigned to the children, and they wore the lenses for 12 months during the first phase. Then, the type of CLs was changed, ie, a crossover design, and the children were observed for another 12 months during the second phase. The end points were changes in axial length and refractive error (spherical equivalent) under cycloplegia. Results The change of axial length in the new-CL and control-CL groups was not different between 12 months and baseline, the change of axial length between 12 months and 1 month in the new-CL group (0.09±0.08 mm) was significantly smaller (47%) than that in the control-CL group (0.17±0.08 mm, P<0.05). During the same period, the change of refractive error in the new-CL group was not significantly different from that in the control group. Neither the change in axial length nor refractive error in the new-CL group was significantly different from those in the control-CL group in the second phase. Conclusion This pilot study suggests that low-addition soft CLs with decentered optical design can reduce the degree of axial elongation in myopic children after an initial transient phase of CL wear. The reduction of the progression of myopia by low-addition soft CLs warrants further investigations.

Visual Performance and Optical Quality of Standardized Asymmetric Soft Contact Lenses in Patients With Keratoconus

Purpose To evaluate the visual performance and optical quality of a standardized asymmetric soft contact lens (SCL) used for correction of higher-order aberrations (HOAs) in eyes with keratoconus. Methods We included 30 eyes (26 patients) with keratoconus (average K: 45.7 ± 2.3 diopters [D]). The patients were subjected to corneal tomography, aberrometry, measurements of manifest refraction and visual acuity (VA), and visual analog scale (VAS) assessments. The study lenses were made using a molding method and consisted of six standardized types, in which an asymmetric power distribution of approximately 2 to 12 D (2-D step) was used to correct HOAs. The lens type suitable for each eye was selected based on the corneal tomography and aberrometry data. The on-eye performance of the lens was evaluated using aberrometry (4-mm pupil), over refraction, VA, and VAS. Results The standardized asymmetric SCL improved the best spectacle-corrected VA from -0.07 ± 0.09 to -0.11 ± 0.08 logMAR (P < 0.05) and the mean VAS score from 66.2 ± 21.8 to 75.4 ± 20.5 (P < 0.05). Vertical coma decreased significantly (-0.50 ± 0.36 μm without SCL; -0.36 ± 0.34 μm with SCL; P < 0.01). In subgroup analysis, subjects in the high VAS group (score ≥ 75) accounted for 70% of all subjects, and this was the group in which the vertical coma decreased significantly from the level without the lens. Conclusions A standardized asymmetric SCL can reduce HOAs and improve vision quality when compared with spectacles in patients with keratoconus who wear rigid gas-permeable lenses.