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Georgios Zoulinakis, Robert Montés-Micó, Teresa Ferrer Blasco, D Robert Iskander; Visual quality with combinations of optimized and non-optimized corrective elements. Invest. Ophthalmol. Vis. Sci. 2016;57(12):3114. doi: https://doi.org/.
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© ARVO (1962-2015); The Authors (2016-present)
To simulate and compare visual quality between combinations of optimized and non-optimized monofocal intraocular (IOL) and contact lenses (CL).
Raw height data of corneal topographies acquired with Medmont E300 Corneal Topographer were used. They included measurements of 10 regular and 12 astigmatic (> 0.75 D) corneas. The data were fitted with a series of Zernike polynomials of the 8th radial order and input in Zemax-EE optical design program (Zemax, LLC). First, 22 customized Liou-Brennan eye models with the first corneal surface replaced with the real corneal data and a pupil size of 3 mm were designed. Then, the crystalline lens was then replaced with either optimized or non-optimized monofocal IOLs. To these models were also added optimized or non-optimized monofocal contact lenses. IOLs and CLs were designed for far focus distance (>6 m). The term optimized stands for lenses which were designed to minimize the wavefront root mean square (RMS) error, while the term non-optimized stands for lenses which have rounded dioptric powers with steps of 0.25 D. To assess the design, wavefront RMS and the visual Strehl ratio based on the optical transfer function (VSOTF) were utilized.
The results were separated between regular and astigmatic corneas and were statistically analyzed. Figure 1 shows the VSOTF and the wavefront RMS for the regular corneas. Paired t-tests between groups with optimized and non-optimized elements showed no statistically significant difference between groups with optimized and non-optimized IOLs (p=0.450). Statistically significant increase was found in VSOTF between groups with optimized IOLs and with either optimized (p<0.001) or non-optimized IOL and CL combinations (p<0.001). There was also a statistically significant decrease of the VSOTF between combinations of optimized and non-optimized IOLs and CLs (p=0.004). Similar results were found in the group of astigmatic corneas.
A combination of two lenses offers a better optical quality, instead of using one fully optimized lens. The combination of two non-optimized lenses offers decreased optical quality from a combination of fully optimized lenses but that decrease amounts on average to less than 0.1 logMAR.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.
Figure 1 VSOTF and wavefront RMS results. IOL stands for intraocular lens, IOL&CL stands for intraocular and contact lens, opt stands for optimized and non opt stands for non-optimized lenses.
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