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Purpose: To analyze the characteristics, incidence, and appearance of wavefront aberrations in undilated, normal, unoperated eyes.
Methods: Eighty-eight eyes of 44 healthy male Mexican subjects (mean age 25.32 years, range 18 to 36 yr) were divided into three groups based on uncorrected visual acuity of greater than or equal to 20/20, 20/30, or 20/40. UCVA measurements were obtained using an Acuity Max computer screen chart. Wavefront aberrations were measured with the Nidek OPD-Scan ARK 10000, Ver. 1.11b. All measurements were carried out at the same center by the same technician during a single session, following manufacturer instructions. Background illumination was 3 Lux.
Results: Wavefront aberration measurements for each group were statistically analyzed using StatView; an average eye was characterized and the resulting aberrations were simulated using MATLAB. We obtained wavefront aberration maps for the 20/20 undilated normal unoperated eyes for total, low, and high order aberration coefficients. Wavefront maps for right eyes were practically the same as those for left eyes. Higher aberrations did not contribute substantially to total wavefront analysis.
Conclusions: Average aberrations of this "normal eye" will be used as criteria to decide the necessity of wavefront-guided ablation in our facilities. We will focus on the nearly zero average of high order aberrations in this normal whole eye as a reference to be matched.
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http://dx.doi.org/10.3928/1081-597X-20040903-11 | DOI Listing |
Continuous zoom afocal systems offer great flexibility for imaging applications. This work investigates the capability and potential of using freeform optics in continuous zoom reflective systems by designing a four-mirror unobscured afocal system with zoom capabilities. The system was optimized at 2X and 3X zoom ratios with a compensated exit pupil.
View Article and Find Full Text PDFA single-shot phase diversity phase retrieval (PDPR) method is proposed utilizing a synthetic computer-generated hologram (CGH). This CGH is designed by synthesizing two phases derived from the decomposition of a complex-amplitude hologram that encodes low-order Lukosz aberration modes. The synthetic CGH introduces multiple phase diversities, enabling the reconstruction of diverse images with high fidelity at the focal plane.
View Article and Find Full Text PDFInt Ophthalmol
March 2025
Department of Ophthalmology, Peking University Shenzhen Hospital, 1120 Lianhua Road, Shenzhen, 518000, China.
Background: We observed the effect of different modified percentage of tissue alteration (mPTA) on corneal higher-order aberrations in small incision lenticule extraction (SMILE), and explored safe threshold values of mPTA for SMILE surgery.
Methods: 148 patients (270 eyes) was retrospectively analyzed and grouped into two groups based on mPTA between 24%. Mixed linear model analysis was used for preoperative and postoperative 1 week (W1), 1 month (M1), 3 months (M3), and 6 months (M6) follow-ups to compare the differences and changes in visual acuity, and corneal higher order aberrations between groups.
Cureus
February 2025
Department of Ophthalmology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Katowice, POL.
Refraction through the ocular system is the process of bending light rays within the eye's optical system, which includes the cornea, anterior chamber, lens, and vitreous body. These structures work together to ensure precise focusing of light on the retina, enabling clear vision. Dysfunction or pathology at any level of the optical system can significantly affect the quality of vision, leading to changes in refractive status and visual acuity disturbances.
View Article and Find Full Text PDFBMC Ophthalmol
March 2025
Department of Ophthalmology, Kayseri City Hospital, Kayseri, Turkey.
Purpose: To analyze the refractive outcomes and changes in corneal aberrations after PRK and SMILE surgeries, and to compare these two methods.
Patients And Methods: This retrospective comparative study investigated patients aged 20-40 years who underwent SMILE or PRK for the correction of myopia between - 1.00 D and - 2.
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