Intraocular Pressure Evaluation after Myopic Refractive Surgery: A Comparison of Methods in 121 Eyes.

PURPOSE: To compare nine different formulas, developed to overcome the underestimation of intraocular pressure (IOP) readings after myopic photorefractive keratectomy (PRK).

METHODS

The correlations between the modified IOP and the preoperative ones in 121 eyes of 72 patients who underwent myopic PRK were evaluated.

RESULTS

The correlation and percentage of eyes in the range of ±2 mmHg were: Emara (R(2) = 0.1686, 74%), Munger (R(2) = 0.1665, 71%), Rosa (R(2) = 0.2489, 82%), Rashad (R(2) = 0.8593, 47%), Duch (R(2) = 0.1631, 82%), Arimoto (R(2) = 0.1638, 77%), Chihara (R(2) = 0.5389, 80%), Svedberg (R(2) = 0.1269, 54%), Kohlhaas (R(2) = 0.1074, 77%). In the case of known preoperative IOP, combining Rashad and Chihara's formulas (R(2) = 0.7730, 97%) were obtained. In the case of unknown preoperative IOP, combining Rosa and Duch's formulas (R(2) = 0.2484, 84%) were obtained.

CONCLUSION

Our results suggest calculating IOP with the average of Rashad and Chihara's formulas if the preoperative IOP is known and the average of Rosa and Duch's formulas if it is unknown.