목적 : 라식 후 백내장 수술 시 Orbscan의 다양한 굴절력지도 중에서 임상병력법과 가장 일치하는 각막곡률값을 알아보고자 하였다. 대상과 방법 : 라식 후 1년 이상 경과관찰이 가능하였던 19명 38안을 대상으로 Orbscan의 mean, axial, tangential, optical power map의 keratometric, anterior, total selection의 1.0 mm, 2.0 mm, 3.0 mm, 4.0 mm, 5.0 mm 각막곡률값과 임상병력법으로 구한 각막곡률값을 비교하였다. 결과 : optical power total map 5 mm 영역이 임상병력법으로 구한 각막곡률값과 가장 높은 상관관계를 보였으며 회귀분석에서 RDKV (refraction-derived keratometric value)=0.9×OPT5 (corneal power of Orbscan optical power total map 5 mm zone)+4.941의 관계를 보였다(r=0.883). 결론 : 라식 후 인공수정체 도수 결정을 위하여 Orbscan을 이용한 각막곡률값 측정시 optical power total map 5 mm영역이 임상병력법으로 구한 각막곡률값을 가장 잘 반영한다.

Purpose: To determine the Orbscan corneal power which gave the best correlation with refraction-derived keratometric value (clinical history method) after LASIK in cataract surgery Methods: A total of 38 consecutive eyes of 19 patients who were followed up for at least 1 year after LASIK were included in study. The refraction-derived keratometric values were correlated with Orbscan corneal power within 1, 2, 3, 4, and 5 mm diameter zones of keratometric, anterior and total selections of mean, axial, tangential and optical power maps. Results: The Orbscan corneal power of the 5-mm zone optical power total map gave the best correlation with refraction-derived keratometric value. The following regular relationship in linear regression analysis was derived: RDKV(refraction-derived keratometric value)=0.9×OPT5(corneal power of Orbscan optical power total map 5-mm zone)+4.941(r=0.883). Conclusions: These results indicate that the corneal power of the 5-mm zone optical power total map was the most appropriate to calculate IOL power in cataract surgery after LASIK when using Orbscan topography.

Purpose: To determine the Orbscan corneal power which gave the best correlation with refraction-derived keratometric value (clinical history method) after LASIK in cataract surgery Methods: A total of 38 consecutive eyes of 19 patients who were followed up for at least 1 year after LASIK were included in study. The refraction-derived keratometric values were correlated with Orbscan corneal power within 1, 2, 3, 4, and 5 mm diameter zones of keratometric, anterior and total selections of mean, axial, tangential and optical power maps. Results: The Orbscan corneal power of the 5-mm zone optical power total map gave the best correlation with refraction-derived keratometric value. The following regular relationship in linear regression analysis was derived: RDKV(refraction-derived keratometric value)=0.9×OPT5(corneal power of Orbscan optical power total map 5-mm zone)+4.941(r=0.883). Conclusions: These results indicate that the corneal power of the 5-mm zone optical power total map was the most appropriate to calculate IOL power in cataract surgery after LASIK when using Orbscan topography.

IOL power calculation, LASIK, Orbscan