Study on the correlation between pachymetry and diopter of myopic eyes in china

Objective To evaluate the corneal pachymetry and the correlation between pachymetry and diopter of myopic eyes in china.Methods The OrbscanⅡ corneal topography system was used to investigate corneal pachymetry on 459 myopia subjects.The investigated sites(diameter is 2mm and 3mm away from visual axis)include corneal centre,superior and inferior part of cornea,superotemporal,inferotemporal,superonasal,inferonasal quarter,temporal and nasal side.The diopter is from -0 50D to -23 50D.The linear correlation between pachymetry and diopter was done.Results The mean corneal thickness of myopic eyes is the least in the centre and the greatest in superonasal quarter.The thinnest point of conea are most located in the inferotemporal.The corneal pachymetry of inferotemporal quarter and temperal side are negatively correlated to diopter(r=-0 117,-0 107, P 0 050).For the color-coded map of corneal thickness,round shape is the commonest type,followed by oval type,eccentric round shape and eccentric oval shape.Conclusions The coneal thickness of inferotemporal quarter and temporal side have the tendency to decrease when the diopter of myopic eyes increase.OrbscanⅡcorneal topography system is a useful instrument for the evaluation of corneal thickness,which has wide usefulness in corneal refractive surgeries.