コンピュータ断層撮影によるcalcified scleral plaqueの検討

Detection of calcified scleral plaque by computerized tomography

　Calcified scleral plaqueの発生頻度を頭部コンピュータ断層撮影（CT）を用いて検討した。頭部CTを施行した239例中6例（2.5％）に高吸収域が水平筋付着部付近に認められ，全例が70歳以上であった。高吸収域を認めた6例中4例で細隙灯顕微鏡によるcaLcified scleral pLaqueを確認した。また超音波生体顕微鏡を施行した1例ではacoustic shadowが認められ，本疾患の特徴的所見と考えられた。高齢者においてCT像で前眼部付近に石灰化像がみられた場合に鑑別疾患の1つとして念頭におくべき病態である。

We reviewed the incidence of calcified scleral plaque as detected by computerized tomography (CT). Out of 239 consecutive cases who underwent CT of the head during a 45-month period, high-density spots in the orbit were detected in 6 cases (2.5%) . A calcified scleral plaque was identified by slit-lamp biomicroscopy in 4 of these 6 cases. All the 4 patients were aged 70 years or older. One of the 4 cases showed an acoustic shadow in the sclera anterior to the insertions of medial and lateral rectus muscles by ultrasound biomicroscopy (UBM) . The findings show that calcified scleral plaque is a possibility when high-density spots are seen in the anterior eye segment by CT imaging in elderly persons.