Clinical analysis of rigid gas permeable contact lens for keratoconus

Abstract

Objective To evaluate the clinical efficacy and safety of RGP for keratoconus.Methods RGP corrected 63 cases of keratoconus in outpatient clinic from 2004 to 2010 were included in this study.Among them 41 males and 22 females,16-35 years old with mean aged (24.6± 7.81),Binoculus in 57 cases,ocellus in 6 cases.The patients who had significantly increased astigmatism and decreased visual acuity with glasses were detected with computer refractometer,corneal topographer and corneal endothelial microscopy for screening keratoconus.For the diagnosed or suspected keratoconus,based on the degree of corneal curvature,use a specially designed or seneral RGP to correct.The corrected visual acuity was measure with RGP and optometry with RGP.All the measured results were analyzed with correlation analysis with SPSS13.0 software,P ＜0.05 was significant differences.Results (1)The mean visual acuity with glasses:0.56+ 0.29,the mean visual acuity with RGP:0.93± 0.20,(t =-14.627,P =0.000).The corrected visual acuity with RGP was significantly better than with glasses.(2)The mean astigmatism before wearing RGP:(-4.16± 2.19)DC,the mean astigmatism with RGP:(-0.77+ 1.2)DC (t =-14.585,P =0.000).There was an obvious decrease of astigmatism with RGP.(3)In average 3.5 years' observation in 22 eyes,only 1 eye appeared corneal increased turbid,implemented lamellar corneal transplantation.There was a significant decreased astigmatism in the other 21 patients.Corneal thickness and corneal curvature were no significant difference.Conclusions RGP for irregular astigmatism of keratoconus can significantly improve the visual acuity to a certain extent and slow down the progress of keratoconus disease. Key words: Keratoconus; Astigmatism; Rigid gas permeable contact lens