ABSTRACT
Objective To investigate the effects of rigid gas permeable contact lens (RGPCL) wearing 3 years on ocular surface in keratoconus.Design Retrospective case series.Participants 73 patients with keratoconus.Methods From July 2001 to July 2004,73 patients (142 eyes) wearing RGPCL for more than 3 years were collected in Peking University Optometry & Ophthalmology Center.Be- fore and at 1 year,2 years and 3 years of RGPCL wearing,density and morphologic changes of corneal endothelium were examined with non-contact specular microscope.Eye axial length,central and peripheral thickness of cornea were measured with A-scan pachymeter. All eyes were examined with slit-lamp microscope periodically.Main Outcome Measures Corneal endothelial density and morphology, corneal thickness,eye axial length,ocular surface changes.Results Before and at 1 year,2 years and 3 years of RGPCL wearing,aver- age corneal endothelial density was 2901.92?445.20,2862.78?497.13,2854.71?526.80,3015.61?421.22 (cells/mm~2)without significant difference statistically (F=1.571,P=0.20).Morphologic changes were not significant during 3 years.Eye axial length was 25.15?1.50, 24.93?1.36,24.78?1.25,25.39?1.31 (mm) without significant difference statistically (F=2.218,P=0.10).Corneal central thickness was 489.09?59.64,484.02?60.80,496.61?59.74,487.44?54.25(?m)without significant difference statistically (F=0.991,P=0.40).Peripheral thickness changes were also not significant statistically during 3 years.69 eyes with mild conjunctival congestion,12 eyes with corneal fluorescence stain and 6 eyes with corneal epithelial rough were found with slit-lamp microscope during follow-up.Conclusions For the patients with keratoconus,long term of RGPCL wear will not lead to significant ocular changes or severe ocular complications.
ABSTRACT
Objective To investigate the change of wave-front aberrations after Ortho-K contact lens(CL)by day and overnight wear.Design Retrospective case series.Participant 180 eyes of 92 myopic patients wearing Ortho-K CL.Method Wave-front aberra- tions of 180 eyes of 92 myopic patients wearing Ortho-K CL were analyzed.Patients were divided into by day wear and overnight wear groups.Wave-front aberrations were measured with WFA 1000B subjective aberrometer before and 1 month after Ortho-K CL wear. Wave-front aberrations at initial,after one month of CL fitting and without CL were measured in same condition,and RMS values for overall wave-front aberrations and each order of the Zernike aberrations were analyzed with Matlab software.Main Outcome Measures RMS value of Zernike coefficient of each order.Result Compared with initial aberration in wear by day group,total RMS and each or- der aberrations(except 2nd order)with lens fitting significantly increased(P0.05).Compared with initial aberration in overnight wear group,overall wavefront aberrations and the RMS(except 2nd,3rd and 6th order Zernike aberrations)with lens fitting significantly increased(P0.05).Conclusion The high order aberrations with lens fitting and without lens fit- ting increased in each group.The aberration with lens fitting in wear by day group was higher than that in overnight wear group,while the aberration without lens fitting in overnight wear group was higher than that in wear by day group.(Ophthalmol CHN,2007,16: 351-354)