Prediction of pseudo-phakic anterior chamber depth from pre-operative data

Multiple linear regression analysis of pre-operative data were used to construct formulas to predict the anterior chamber depth 3 months after implantation of two different posterior chamber lenses. The resulting formulas differed widely. For lens I (27 eyes) the formula had a correlation coefficient of 0.78 and a standard deviation of +/- 0.2 mm. The corresponding figures for lens II (41 eyes) were 0.52 and +/- 27 mm. For lens I the predictors of significance were axial length (P less than 0.0001) and anterior corneal curvature (P = 0.07). For lens II significant predictors were patient age (P = 0.0008) and pre-operative anterior chamber depth (P = 0.04). We suggest that post-operative anterior chamber depth may not solely depend on the dimensions of the eye, but also on the lens architecture and the 'memory' of the lens haptics. We conclude that formulas to predict post-operative anterior chamber depth should be derived empirically for each lens type separately.