Clinical data are most useful in the management of patients with complex medical problems if they are accurate, reliable, and easily accessible by physicians and the medical community at large. Furthermore, the data are most valuable when they can be shared among cooperating institutions. We describe a computer system which exhibits a uniform taxonomy, an integrated on-line dictionary of clinical terms, a coherent temporal layout, and persistent spatial integrity with regard to the values of the variables. The system is user friendly and provides real time data access which can be retrieved by structured query language or may be programmed to be used as part of an international network in the management of patients with retinoblastoma, a malignant and potentially fatal tumor of childhood. Furthermore, because of its design flexibility, this system provides for potential application to other ophthalmic disorders, such as malignant uveal melanoma, and other areas of medicine as well.