An initial clinical report on the Rose K rigid gas permeable contact lenses for correcting advanced keratoconus with refractive errors

Abstract

Objective To observe the clinical outcome of the Rose K rigid gas permeable contact lens (RGPCL) used to correct advanced keratoconus with refractive errors.Methods Fifty-nine eyes of 55 patients with advanced keratoconus who were fitted at the Shandong Eye Hospital with a Rose K RGPCL between February 2011 and May 2012 were included in this retrospective study.Fluoresein staining was used to fit the contacts lenses.Differences in mean values among groups were compared with a one-way ANOVA.The corneal curvature values of a 9 mm diameter centered on the apex of the topographic map were compared for the 4 meridians of 0°,90°,180°,270°.Uncorrected visual acuity (UCVA),best spectacle-corrected visual acuity (BSCVA) and best-corrected RGPCL visual acuity (RGPCLVA) were compared.Visual acuity under the same contrast were compared for UCVA,BSCVA and RGPCLVA.The curvature radius of the flat meridian (Sim KI),steep meridian (Sim K2),and mean K were compared with the base curve (BC) of the RGPCL.Results There were significant differences between the corneal curvature values of the 4 peripheral points and the apex on the topographic map (P＜0.01).The Rose K RGPCL reached an ideal fit by fluoresein staining.There were statistically significant differences between RGPCLVA and UCVA or BSCVA (P＜0.01).And the same outcomes were found for the 100％,25％,10％ and 5％ contrast visual acuity charts.There were no significant differences in the relationship between the BC of RGPCL and the residual Sim K1 or mean K.Conclusion The Rose K RGPCL lenses provide ideal fitting,good visual acuity and contrast vision for advanced keratoconus.The trial Rose K RGPCL was chosen based on the Sim K1 or mean K. Key words: Keratoconus; Contact lenses,rigid,Rose K; Contrast sensitivity; Corneal topography