Hematologic disorders.

Hematology is the study of the cellular elements of blood. Essentially all diseases affect blood components and compromise their important functions, which include transport of nutrients and wastes, cellular defenses, and clot formation. When the disease process manifests itself in the eye, the optometrist should make every effort to determine an underlying cause. This chapter attempts to provide a basic understanding of laboratory tests evaluating hematologic function and to develop a diagnostic approach toward this group of disorders.