Imaging of developmental anomalies of the eye and the orbit.

The development of the eye and the orbit encompasses a series of stages that take place during the embryonic and fetal periods (1-4). These stages overlap each other temporally , and are interrelated. Multiple diverse genetic and acquired conditions may derange this normal pattern of development. The specific type of anomaly that results, however, depends more heavily on the time that the insult or the developmental arrest occurred than on the specific etiology of the derangement (5). Familiarity with the sequence of developmental events is a prerequisite for understanding the various anomalies of the visual organ and for correct interpretation of diagnostic studies. Imaging modalities now allow precise delineation of the ocular and orbital (6) anomalies and of any associated central nervous system, facial (7), and systemic abnormalities. Such information may be critical in planning the treatment and management of the patient, as well as in establishing a prognosis.