Measurement of Central Keratometric Value with Orbscan II(R) Topography after LASIK

ABSTRACT

PURPOSE: To compare central keratometric values (K-values) measured at the pupillary center by Orbscan II (R) topography (Orbtek, Bausch & Lomb, USA) with preexisting methods for K-values in patients who have been treated with laser in situ keratomileusis (LASIK). METHODS: A total of 36 consecutive eyes of 25 patients who were treated with LASIK for myopia have been followed up for more than 1 year. Central K-values measured by Orbscan II(R) topography, K-values measured with autorefractokeratometer, and refraction-derived K-values were compared . RESULTS: The mean central keratometric K-value measured by Orbscan II (R) topography was 39.65+/-1.94 (35.82 to 43.45) diopter (D), and was not statistically significantly different from the mean refraction derived K-value which was 39.63+/-1.95 D (35.95 to 43.41) (p>0.05), but was statistically lower than the mean K-value measured with autorefractokeratometer which was 40.23+/-1.76 D (36.56 to 43.69) (P<0.05). CONCLUSIONS: In patients who have been treated with LASIK for myopia, central keratometric K-value measured with Orbscan II R topography is not statistically significantly different from refraction derived K-value, but is lower than K-value measured with autorefractokeratometer.