술 전 사시각에 따른 양안 외직근후전술 후 시간경과에 따른 교정 효과 변화

Changes in the Effects of Bilateral Lateral Rectus Muscle Recession According to Preoperative Angle Deviation

목적: 기본 간헐외사시의 술 전 사시각이 큰 군과 작은 군에서 양안 외직근후전술 후 교정 효과가 어떻게 변하는지 단위 길이당 교정효과 변화를 통해 알아보고자 하였다. 대상과 방법: 2007년부터 2014년까지 큰 각과 작은 각의 간헐 외사시로 양안 외직근후전술을 시행하고 2년 이상 관찰한 165명을 후향 분석하였다. 수술 전후 시점에 따라 원거리, 근거리 사시각을 측정하여 외편위 회귀양상을 관찰하였고, 각 관찰시점에서 후전술 단위길이당 외사시 각 교정 효과를 얻었다. 최종 시점에서 눈 위치가 내편위 5PD 이하, 외편위 10PD 이하로 유지될 때 수술 성공으로 정의하였다. 결과: 큰 각 84명과 작은 각 81명이었으며, 술 전 사시각은 큰 각 39.34 ± 5.13PD, 작은 각 19.49 ± 1.62PD, 양안 외직근후전술 후 1일째 -8.32 ± 9.31PD, -13.11 ± 6.94PD (p<0.001), 최종 관찰시점에 4.63 ± 8.94PD, 1.22 ± 8.01PD (p=0.011)를 보여 외편위회귀를 보였다. 최종 시점에서 후전술 단위 길이당 사시각 교정 효과는 큰 각 2.25 ± 0.62PD/mm, 작은 각 1.94 ± 0.78PD/mm로, 큰 각에서 단위 길이당 교정 효과가 크게 나타났다(p=0.005). 수술 성공률은 각각 75.0%, 80.2%였다(p=0.268). 결론: 사시각이 작은 군에서 초기 과교정이 컸으나 최종 시점의 단위 길이당 교정 효과가 유의하게 적었고, 큰 군에서 초기 과교정은 작았으나 최종 시점의 단위 길이당 교정 효과가 유의하게 컸다. 최종 시점에서 수술 성공률에는 유의한 차이가 없었다.

Purpose: To investigate how the effect of bilateral rectus muscle recession changed by analyzing the effect/dose ratio of surgery according to the preoperative angle deviation. Methods: We retrospectively studied the medical records of patients from January 2007 to March 2014 who underwent bilateral lateral rectus muscle recession and who visited our hospital for at least 2 years after surgery. We classified the patients into two groups: the preoperative large angle deviation group (35 prism diopters [PD] or more) and the small angle deviation group (20 PD or less). We observed exodrift patterns by measuring distant and near angle deviation according to the preoperative and postoperative times. The effect/dose ratio of recession was calculated at each visit. Surgical success was defined as an alignment between 10 PD of exodeviation and 5 PD of esodeviation, both at distance and at near. Results: Among 165 patients, 84 patients were in the large angle deviation group and 81 patients were in the small angle deviation group. Preoperative angle deviation of the large angle deviation group was 39.34 ± 5.13 PD (range: 35-55 PD) and the small angle deviation group was 19.49 ± 1.62 PD (range: 18-20 PD) (p < 0.001). At postoperative 1 day, the alignments of eyes of the two groups were -8.32 ± 9.31 PD and -13.11 ± 6.94 PD; p < 0.001, respectively. At the date of the final follow-up, the alignments of eyes of the two groups were 4.63 ± 8.94 PD and 1.22 ± 8.01 PD; p = 0.011, respectively, and the effect/dose ratios were 2.25± 0.62 PD/mm and 1.94 ± 0.78 PD/mm, respectively, which meant that the effect of correction for the large angle deviation group was larger than that of the small angle deviation group (p = 0.005). Both groups showed postoperative exodrift patterns and similar success rates (75.0% and 80.2%, respectively), which showed no significant difference (p = 0.268). Conclusions: The small angle deviation group showed a larger effect of correction and high exodrift pattern at the postoperative initial time and the large angle deviation group showed a smaller effect of correction and low exodrift pattern at the postoperative initial time. The preoperative angles of deviation and the operative success rates were not related.