[Application of SRK II formula and measurement of A constant of KM intraocular lens].

The characteristics and distribution of the axial lengths and the results of keratometric measurements of 757 eyes with senile cataracts were reported and their relationship was discussed. The range of the axial lengths was 19.53-33.74 mm, the mean value being 23.81 +/- 2.26 mm (mean +/- SD), the eyes with longer axial lengths accounting for 21.8% and the eyes with axial lengths over 27 mm, 8.59%. The range of the degrees of the corneal curvatures was 39.75-50.50 D, the mean value being 44.47 +/- 0.78 D. The corneal curvatures of the eyes with shorter axial lengths are increased markedly with the shortening of the axial lengths. However, the corneal curvatures of the eyes with longer axial lengths are not decreased significantly with the lengthening of the axes. The A constant of KM intraocular lens we measured is 116.86 and the post-operative mean anterior chamber depth is 3.63 +/- 0.28 mm. If the C value is + 1.5 in eyes with 21-22 mm axial lengths, 0 in eyes with 22-24.5 mm and -0.5 in eyes with > 24.5, > 27, > 28.5 mm, the predictive error seen post-operatively is the smallest.