IOLMaster versus manual keratometry after photorefractive keratectomy

ABSTRACT

To compare keratometric measurements using a Javal type manual keratometer with IOLMaster in eyes undergoing photorefractive keratectomy [PRK] for myopia. In this comparative case series, we studied patients aged 21 to 27 years scheduled for myopic PRK. Keratometry was performed preoperatively and three months after the procedure using a Javal type manual keratometer and the IOLMaster. We compared postoperative measurements obtained by both instruments with the clinical history method [CHM]. Seventy eyes of 35 patients with mean age of 23.45 +/- 1.55 years were studied. Mean preoperative spherical equivalent was -4.53 +/- 1.3 D. Average preoperative IOLMaster and manual keratometric readings were 45.95 +/- 1.23 D and 46.32 +/- 1.18 D, respectively. Postoperatively, mean IOLMaster measurements was 38.03 +/- 0.68 D and that of manual keratometry was 43.15 +/- 1.1 D. Compared to CHM measurements, the 95% limits of agreement were -5.95 to -0.85 for the IOLMaster and -1.44 to 4.04 for manual keratometry. Keratometric measurements with the IOLMaster and a Javal type manual device are comparable after PRK; both are largely deviant from the CHM and can yield misleading results: