Correlated study of axial length, diopter, keratometric power and central corneal thickness in high myopia

Abstract:

AIM:To study the correlation of the axial length(AL), diopter(D), keratometric power (K₁,K₂) and central corneal thickness(CCT) of high myopia.METHODS :Eighty cases(158 eyes ) were divided into 3 groups depending on their diopters: 26 cases(46 eyes) with diopters arranged from -6.00D--9.00D in group A (myopia group); 57 cases(97 eyes) with diopters arranged from -9.25D--20.00D in group B (high myopia group); 9 cases(15 eyes) with diopters over 20.25D in group C (super high myopia group). AL, diopter, keratometric power and CCT of three groups were measured. RESULTS: There were significant difference(P<0.05) among AL values of three groups (group A: 26.75±015mm; group B: 29.25±0.19 mm; group C: 32.27±0.84mm). Positive correlations existed between AL values and diopters of three groups （r=0.352,0.715,0.622;P<0.05）,while negative correlations between AL values and K₁、K ₂（r₁=-0.630,-0.494,-0.750, r₂=-0.609,-0.465,-0.782;P<0.05）. Positive correlations existed between diopters and K₁,K₂ in group A, while did not exist in group B and C. No correlation existed between CCT and diopters of three groups.CONCLUSION: Axial growth was the main influence factor of high myopia, keratometric power was the second factor, and CCT has no influence.