목적 : 라식 수술을 받은 환자에서 Orbscan II와 각막곡률계산법에 의한 각막곡률 간의 상관 관계를 알아 보았다. 대상과 방법 : 라식 수술 후 6개월 이상 관찰한 43명(77안)을 대상으로 Orbscan II를 이용한 Sim-K, 0.5, 1.0, 1.5, 2.0, 3.0 mm 지름의 평균 축곡률지도에 의한 곡률(AP), 1.5, 2.0, 3.0, 3.5, 4.0, 5.0 mm 지름의 총각막곡률(TOP)을 각막곡률계산법으로 구한 곡률(CK)과 비교하였다. 결과 : Sim-K, AP의 모든 측정값은 CK보다 유의하게 높았으나(P<.001), TOP의 모든 측정값은 CK보다 유의하게 낮았고(P<.001), 그 중 3.0 mm와 4.0 mm 지름의 TOP가 가장 높은 상관성을 보였다(r2=0.889, P<.001, r2=0.889, P<.001). 술 전 구면렌즈대응치가 –6D 미만이고 술 후 각막두께가 470 ㎛ 이상인 경우에 TOP 4.0 mm 지름에서(r2=0.894, P<.001), 술 전 구면렌즈 대응치가 –6D 이상이고 술 후 각막두께가 470 ㎛ 미만인 경우에는 3.0 mm 지름의 TOP가 가장 높은 상관성을 보였으나(r2=0.800, P<.001) CK와의 상관성은 비교적 낮았다. 결론 : Orbscan II의 3.0 mm와 4.0 mm 지름의 TOP가 CK와 가장 높은 상관성을 보였으나, 고도 근시 환자에서는 상관성이 비교적 낮았고 그 중 3.0 mm 지름의 TOP가 가장 높은 상관성을 보였다.

Purpose: To evaluate the relation between clinical history method and Orbscan Ⅱ for corneal power measurement after laser in situ keratomileusis (LASIK). Methods: A total of 77 consecutive eyes of 43 patients who were treated with LASIK for myopia were followed up for at least 6 months. Corneal power by clinical history methods (CK) was compared with 3.0 mm zones of simulated keratometry (Sim-K), with 0.5, 1.0, 1.5, 2.0 and 3.0 mm zones of axial power maps (AP) and with 2.0, 3.0, 3.5, 4.0 and 5.0 mm zones of total optical power maps (TOP). Results: Sim-K and all AP-map zones using Orbscan II were significantly higher (P<.001) than the CK value, while all TOP-map zones were significantly lower (P<.001) than the CK value. Among them, 3.0 and 4.0 mm TOP-map zones showed the highest correlation with the corneal power by CK (r2=0.889, P<.001; r2=0.889, P<.001). The correlation was higher with 3.0 mm TOP-map zone (r2=0.800, P<.001) than with 4.0 mm TOP-map zone (r2=0.793, P<.001) in high myopia patients. Conclusions: Although 3.0 and 4.0 mm TOP-map zones of Orbscan II were correlated highly with the CK value, these correlations were relatively low in high myopia patients and 3.0 mm TOP-map zone was better correlated than 4.0 mm TOP-map zone in these patients.

Purpose: To evaluate the relation between clinical history method and Orbscan Ⅱ for corneal power measurement after laser in situ keratomileusis (LASIK). Methods: A total of 77 consecutive eyes of 43 patients who were treated with LASIK for myopia were followed up for at least 6 months. Corneal power by clinical history methods (CK) was compared with 3.0 mm zones of simulated keratometry (Sim-K), with 0.5, 1.0, 1.5, 2.0 and 3.0 mm zones of axial power maps (AP) and with 2.0, 3.0, 3.5, 4.0 and 5.0 mm zones of total optical power maps (TOP). Results: Sim-K and all AP-map zones using Orbscan II were significantly higher (P<.001) than the CK value, while all TOP-map zones were significantly lower (P<.001) than the CK value. Among them, 3.0 and 4.0 mm TOP-map zones showed the highest correlation with the corneal power by CK (r2=0.889, P<.001; r2=0.889, P<.001). The correlation was higher with 3.0 mm TOP-map zone (r2=0.800, P<.001) than with 4.0 mm TOP-map zone (r2=0.793, P<.001) in high myopia patients. Conclusions: Although 3.0 and 4.0 mm TOP-map zones of Orbscan II were correlated highly with the CK value, these correlations were relatively low in high myopia patients and 3.0 mm TOP-map zone was better correlated than 4.0 mm TOP-map zone in these patients.

Clinical history method, Corneal power measurement, Orbscan II