INTRAOCULAR-LENS PREDICTION AND OCULOMETRIC HARMONY - WITH SPECIAL REFERENCE TO SKEW RATIOS BETWEEN AXIAL LENGTH AND CORNEAL CURVATURE RADIUS

The oculometric features have been analysed in two groups of cataract patients, each comprising 30 subjects. All had undergone ECCE and inse rtion of biconvex Rayner 2 Superflex posterior chamber IOL. Using Bink horst and SRK II routinely, the groups were given by a good fit betwee n methods (discrepancy between emmetropia predictions numerically < 1 D) and a poor fit (actual discrepancy range 1.6-4.1 D, all with the sa me sign, the lower values being predicted by Binkhorst). A certain ove rlapping between groups was found regarding axial length and corneal c urvature radius, the ranges being 21.5-25.1/22.7-29.9 mm and 7.3-8.5/7 .2-8.1 mm, respectively. In contrast there was no overlapping regardin g the ratio between axial length and corneal curvature radius; the ran ges were 2.80-3.05 and 3.06-3.90 in the two groups. Evaluating the act ual prediction errors by the two methods (follow-up after at least 4 m onths), they did not primarily pertain to very short or very long eyes , as usually advanced. Skew ratios between axial length and corneal cu rvature appeared more decisive. Possible implications for the current IOL prediction formulas, including the newer generations, are discusse d.