Comparison of Corrected Intraocular Pressure Methods after Corneal Refractive Surgery according to Corneal Ablation Amounts

Abstract

Purpose : The purpose of this study was to evaluate the intraocular pressure (IOP) that would be underestimated after corneal refractive surgery according to corneal ablation amounts, and was to suggest the most appropriate corrected IOP method for each group. Methods : The subjects were 1,002 eyes of 501 people (237 men, 264 women) who underwent corneal refractive surgery. The mean age was 26.89±5.18 years. IOP was measured with a non-contact tonometer and 4 correction methods, and was used to correct the underestimated IOP. IOP in three groups with low, moderate and high myopia according to ablation amounts was analyzed postoperative corrected IOP to compare correction methods. Results : The preoperative IOP was 15.67±2.39 mmHg and postoperative IOP was 10.12±2.11 mmHg, which was significantly lower than the mean 5.55±2.09 mmHg. The postoperative IOP calculated by Ehlers' correction method was 14.53±2.47 mmHg, which was 1.14±2.83 mmHg different from the preoperative IOP, showing the most similar to preoperative IOP. In addition, the IOP corrected by the Ehlers equation showed the smallest difference from preoperative IOP in all groups. Conclusion : The Ehlers correction method is shown the most accurate among the four correction methods in low, moderate, and high myopia groups after corneal refractive surgery. It would be a useful method for preventing the late diagnosis and treatment of glaucoma.