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Koray Gumus, Nisa Parmaksiz; A new alternative fitting approach for providing an adequate comfort and visual performance in keratoconus: Soft HydroCone (Toris K) silicone hydrogel keratoconus lenses. Invest. Ophthalmol. Vis. Sci. 2014;55(13):6078.
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© ARVO (1962-2015); The Authors (2016-present)
To evaluate the visual comfort and performance of a new alternative approach, soft HydroCone (Toris K) silicone hydrogel lenses, in keratoconus patients.
Forty-three eyes of 34 keratoconic patients (11 male and 23 female, mean age 24.7, ranged 16 - 39) who were fitted with soft HydroCone silicone hydrogel lenses were included in the study. All patients were evaluated at baseline and after two weeks of lens wear. Uncorrected and best spectacle/contact lens corrected visual acuity, manifest and topographic refractive indices, ocular higher order aberrations, and point spread function (the Strehl ration) were noted in all visits. Ocular health status including bulber hyperemia, corneal and conjunctival staining was also evaluated. Comfort level and visual performance in both daytime and nighttime conditions were scored 0-5 (0: worst, 1: bad, 2: fair, 3: moderate, 4: good, 5: excellent) after 2 weeks of lens wear.
Best-corrected visual acuity was significantly better with the lens than spectacles (p< 0.001). The mean increase in visual acuity was 4.2 lines (range, 0 to 9 lines). Mean Kmax values were significantly decreased from 53.4 D to 46.5 D with the lens (p< 0.001). The mean baseline topographical spherical equivalent values were significantly decreased from -5.3 to -1.3 with the lens (p< 0.001). While total ocular aberrations were significantly decreased with the lens (p< 0.001), the difference in total higher-order aberrations did not reach to the statistically significant level (p= 0.234). However, total coma, trefoil, and higher-order astigmatism were significantly decreased with the lens (respectively, p= 0.023, p= 0.028 and p= 0.018). Moreover, point spread function, the Strehl ratio, was significantly increased with the lens (p= 0.002). The higher the Strehl ratio, the better the potential image quality. While comfort in 39 eyes (90.7%) was classified as good/excellent, only 4 eyes (9.3%) had moderate comfort scores. Visual acuity was classified as good/excellent in 41 eyes (95.3%) in daytime and in 34 eyes (79%) in nighttime conditions.
Soft HydroCone (Toris K) silicone hydrogel keratoconus lenses should be considered as a new alternative fitting approach for keratoconus patients providing optimal comfort and visual performance.
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