初診時無眼球症を疑われた小眼球症の1例

A case of microphthalmos initially suspected of anophthalmos

要約　目的：初診時に無眼球症が疑われた小眼球症の症例の報告。症例：生後6日目の男児が，左眼眼窩部の陥凹で紹介され受診した。満期産の正常分娩で，出生時体重は3,274gであった。2歳の姉には先天異常はない。母親は患児の出生前に自然流産があり，その際に胎児に異常があったといわれた。両親間に近縁関係はない。所見：左眼窩部は陥凹し，瞼裂が狭小化，球結膜は平坦化し，無眼球症と思われた。磁気共鳴画像検査（MRI）で，左眼窩部に眼軸長6.55mmの眼球があり，眼球内部に高吸収域があった。右眼は正常であり，全身奇形はなかった。結論：本症例は第1次硝子体遺残を伴う片眼性の小眼球症と診断され，神経堤細胞の遊走不全が関係していると推定される。

Abstract.　Purpose：To report a case of unilateral microphthalmos who was suspected of anophthalmos at the initial examination. Case：A 6-day-old male infant was referred to us for depression of left orbital area. He had been born full term weighing 3,274 g. His 2-year-old sister had no congenital anomaly. His mother had had spontaneous abortion and been told of congenital anomaly in the fetus. His parents were not relatives. Findings：His left orbital area was depressed with reduced lid opening. The surface of bulbar conjunctiva was flat with no sign of eyeglobe. Magnetic resonance imaging（MRI）showed a small eyeglobe with axial length of 6.55 mm. A high-density mass was present within the eyeglobe suggesting persistent hyperplastic primary vitreous. His right eye was normal. He was free of systemic deformities. Conclusion：The present case simulated anophthalmos initially but was actually microphthalmos with suspected persistent hyperplastic primary vitreous.