The Clinical Study Of Corneal Endothelial Cell Density And Percentage Of Hexagonal Cells With Overnight Orthokeratology

Background The myopic elementary school child is more and more popular in Taiwan. Glasses, soft contact lenses, rigid gas-permeable contact lenses and surgery are the main ways to correct visual acuity. Orthokeratology is defined as a reduction, modification, or reduce refractive anomalies by the programmed application of contact lenses to reduce myopia and improved in unaided vision by flattening the cornea curvature temporary since early1960s. The safety and efficacy of the daily wearing orthokeratology were confirmed by using reverse-geometry rigid gas-permeable lenses in the1990s.Overnight wearing the new gas-permeable material made lenses became possible, providing acceptable unaided vision lasting in day time after the reverse-geometry rigid gas-permeable lenses are removed.Objectives To evaluate the influence of overnight wearing gas-permeable material made orthokeratology on the corneal endothelium of myopic elementary school child with two years follow.Methods1Using Topcon Specular Microcope SP-3000P to analyze the density and hexagonal percentage of the corneal endothelium cells before and after two years wearing overnight gas-permeable material made orthokeratology.of two kinds allergic diseases.2Sixty-eight healthy eyes of34patients aged7to15undergoing overnight wearing gas-permeable material made orthokeratology. 3Collected data of two years follow up examinations were compared with baseline examinations using paired t test.Results1Improved uncorrected visual acuity from0.75(0.13to0.11)±0.14logMAR.2Reduced significantly refractive errors from-2.52±1.21D (mean standard deviation) to-0.25±0.35D.3The endothelial cell density was not significantly changed(3250±261cells/mm2before and3196±262cells/mm2after treatment(p=0.230, paired t test)4The percentage of hexagonal cells was69.8±7.08%before wearing and71.6±7.05%after wearing (p=0.131, paired t test).Conclusion1. The variations of corneal endothelial cell density and percentage of hexagonal cells with two years wearing gas-permeable material made orthokeratology were not statistically significant.2Long-term orthokeratology wearing should be further studied.