限界反射距離-1（MRD-1）の測定における第二世代掃引線源前部セグメントOCTの応用

Application of Second-Generation Swept-Source Anterior Segment-OCT in the Measurement of Marginal Reflex Distance-1 (MRD-1).

• Kosuke Ogasawara

抄録

目的:

第二世代掃引源前セグメント光コヒーレンス断層撮影法（AS-OCT）を用いて健常者と眼瞼下垂症患者の限界反射距離-1（MRD-1）値を測定し、本測定法の有用性を評価することを目的とした。

Purpose: To measure marginal reflex distance-1 (MRD-1) values in normal subjects and patients with blepharoptosis using second-generation swept-source anterior segment optical coherence tomography (AS-OCT) and to evaluate the usefulness of this measurement method.

材料および方法:

神経学的・内分泌学的障害のない20～59歳の健常者40名（男性16名、女性24名）の80眼を対象にAS-OCTを用いてMRD-1値を測定し、20歳代、30歳代、40歳代、50歳代の各10名ずつの20眼からなる4つの年齢群間で測定値を比較した。健常者２０人の４０眼において、同時にＶｏｌｋアイチェックシステムを用いてＭＲＤ-１を測定し、ＡＳ-ＯＣＴで得られた測定値と比較した。連続した13例の起立性眼瞼下垂症患者（48～84歳、平均70.2歳）の21眼において、AS-OCTを用いて術前と術後3ヶ月後にMRD-1値を測定し、測定成功率と術前・術後の結果を検討した。

Materials and Methods: MRD-1 values were measured using AS-OCT in 80 eyes of 40 normal subjects (16 men and 24 women) aged 20-59 years with no neurological or endocrinological disorders, and the measured values were compared between four age groups comprising 20 eyes of 10 subjects each in their 20s, 30s, 40s, and 50s. The Volk Eye Check system was simultaneously used to measure MRD-1 in 40 eyes of 20 normal subjects, and the measured values were compared with those obtained using AS-OCT. In 21 eyes of consecutive 13 involutional blepharoptosis patients (48-84 years of age, mean 70.2 years), MRD-1 values were measured using AS-OCT preoperatively and 3 months after surgery to examine the rates of successful measurements as well as preoperative and postoperative results.

結果:

健常者40名80眼のAS-OCTを用いたMRD-1の平均値は3.70±0.10mmであったのに対し、4つの異なる年齢層からそれぞれ10名ずつの被験者20眼の値は4.01±0.54mm、3．88±0.60mm、3.96±0.77mm、2.94±0.79mmであり、50代群とそれ以外の群では有意差が認められた（p＜0.01）。健常者20名の40眼におけるAS-OCTおよびVolk Eye Checkシステムを用いた平均MRD-1値は、それぞれ3.68±0.70mm、3.71±0.84mmであり、有意差は認められなかった(p:0.87)。Involutional blepharoptosisを有する患者の術前および術後のMRD-1の平均値は、それぞれ0.29±0.70mmおよび3.24±0.92mmであった；AS-OCTを用いたMRD-1測定の成功率は被験者の間で100%であった。

Results: The mean MRD-1 value using AS-OCT in 80 eyes of 40 normal subjects was 3.70 ± 0.10 mm, whereas the values in 20 eyes of 10 subjects each from the four different age groups were 4.01 ± 0.54 mm, 3.88 ± 0.60 mm, 3.96 ± 0.77 mm, and 2.94 ± 0.79 mm for subjects in their 20s, 30s, 40s, and 50s, respectively; significant differences were observed between the 50s group and other groups (p<0.01). The mean MRD-1 values using AS-OCT and the Volk Eye Check system in 40 eyes of 20 normal subjects were 3.68 ± 0.70 mm and 3.71 ± 0.84 mm, respectively, with no significant differences (p:0.87). The mean preoperative and postoperative MRD-1 values in patients with involutional blepharoptosis were 0.29 ± 0.70 mm and 3.24 ± 0.92 mm, respectively; the rate of successful MRD-1 measurements using AS-OCT was 100% among trial subjects.

結論:

AS-OCTを用いたMRD-1測定は、単純で再現性の高い方法であり、健常者だけでなく、眼瞼下垂症の患者さんでも数値を直接比較することができます。

Conclusion: MRD-1 measurement using AS-OCT is a simple and reproducible method that allows the direct comparison of numerical values in normal subjects as well as in patients with blepharoptosis.

© 2020 Ogasawara.