SYSTEMATIC-ERROR IN COMPUTERIZED PACHYMETRY

In a polycentric study, the influence of some of the most common varia bles capable of influencing the reliability of prekeratotomy pachymetr y has been evaluated. The fluctuation in a sequence of measurements fr om the same point on the cornea, with the patient in different positio ns (orthostatic and clinostatic), during progressive drying of the lac rimal film and before and after corneal marking have been evaluated. T hree operators, working randomized, used the same computerized pachyme ter (DGH1000) to make the measurements. The data obtained in this way were statistically analyzed by the Statgraphics personal computer prog ram. Some interesting and useful considerations about the more correct methods to run the test and its real accuracy have emerged.