重篤な角膜潰瘍を伴ったビタミンA欠乏性眼球乾燥症の1例

A case of xerophthalmia due to vitamin A deficiency with severe corneal ulcer

要約　目的：発症から時間が経過し，重篤な角膜潰瘍を伴ったビタミンA欠乏性眼球乾燥症の1例を経験したので報告する。

症例：症例は6歳，男児。母親が右眼の角膜混濁に気づき前医を受診し，眼内炎の診断で精査加療目的に鹿児島大学病院に紹介され受診となった。細隙灯顕微鏡にて，両眼角結膜の著明な乾燥および右角膜潰瘍と前房蓄膿を認めた。問診にて自閉スペクトラム症を伴う発達障害があることがわかり，極端な偏食および夜盲の症状があったため，ビタミンA欠乏性眼球乾燥症と診断しレチノールパルミチン酸エステル（チョコラ^® A筋注5万単位）筋肉注射5万単位/日を5日間投与したところ，角膜混濁を残して角膜潰瘍は消失し，結膜も湿潤・光沢を認め乾燥所見も改善した。また加療前は血清ビタミンA低値（≦3.0μg/dL）であったが，加療後は31.6μg/dLまで上昇した。

結論：ビタミンA欠乏性眼球乾燥症は，本症例のように重篤な炎症を伴うと感染性の眼病変と鑑別が困難となり加療の遅れにつながるため，詳細な問診と当疾患を念頭に置いた眼科的診察がより重要となると考えられる。

Abstract　Purpose：To report a case of xerophthalmia due to vitamin A deficiency with severe corneal ulcer that occurred long after the disease onset.

Case：A 6-year-old boy was referred to our hospital for the treatment of endophthalmitis after his mother noticed corneal opacity in the right eye and visited his previous doctor.

Findings and Clinical Course：The patient had corneal dryness and conjunctiva in both eyes, corneal ulcer and hypopyon in the right eye. He had developmental disabilities including autism spectrum disorder, an extremely limited diet, and night blindness. A diagnosis of xerophthalmia due to vitamin A deficiency was made for which vitamin A was administered at a dose of 50,000 units per day for 5 days. The corneal ulcer disappeared, leaving corneal opacity, and the conjunctival dryness also improved. His serum vitamin A level was low（≤3.0 μg/dL）, but it increased to 31.6 μg/dL after treatment.

Conclusion：When xerophthalmia due to vitamin A deficiency is accompanied by severe inflammation, it is difficult to distinguish from infectious ocular lesions, leading to delayed treatment. A detailed interview and examination with this disease in mind is important.