Observation of the correcting effect for keratoconus patients with rigid gas-permeable lenses

Objective To evaluate the treatment efficacy of rigid gas permeable contact lens (RGPCL) for correcting the irregular astigmatism patients with keratoconus.Methods From January 2010 to December 2012,a retrospective analysis of 72 eyes from 40 patients with keratoconus were collected in our hospital.According to the Sim Kmax value,the keratoconus were divided into two groups:the mild keratoconus group and the moderate to severe keratoconus group.Sim Kmax ≤ 47D was the mild keratoconus group (24 patients,43 eyes),and Sim Kmax ＞47D was the moderate to severe keratoconus group (16 patients,29 eyes).The best corrected visual acuity,the findings with slit-lamp microscopes and the change of ocular health were observed at beginning,six and twelve months after the fitting with RGPCL.Results Among the 40 patients (72 eyes),there were 38 patients (70 eyes) completed the 12 months' follow up.The good corrected visual acuity was observed in all of the patients who completed the 12 months' follow up after fitting with RGPCL.The progression of corneal ectasia was prevented and the ocular complications with RGPCL were not found.Among another two patients (2 eyes),One patient (one eye) in mild group was given up because of intolerance with the fitting.Another one patient (one eye) in the moderate to severe group was received the penetrating keratoplasty because of the progression of the corneal ectasia and decreased of visual acuity.Conclusions The exciting fitting with RGPCL for the patients with severe keratoconus with a longtime could significantly improve the corrected visual acuity,and prevent the progression of corneal ectasia or delay the time of the keratoplasty operation. Key words: Keratoconus;  Rigid gas-permeability contact lenses;  Corrected visual acuity