Abnormal development (dysgenesis) of the anterior segment of the eye globe. These structures are mainly of mesenchymal origin. The phenotype is Ocular anterior segment dysgenesis (HP_0007700). Also known as: Anterior chamber cleavage defect, Anterior chamber cleavage disorder, Anterior chamber malformation, Anterior chamber mesodermal anomalies, Anterior segment developmental abnormality, Anterior segment dysgenesis, Anterior segment mesencyhmal dysgenesis, Anterior segment ocular dysgenesis.