Blood disorders

Abstract

This chapter discusses blood disorders. Retinal hemorrhages are seen and some have white centers (Roth spots). Retinal infarcts and edema may also be present. This retinopathy rarely occurs unless the hemoglobin levels are less than 50% of normal, and other factors such as platelet deficiency and hypoxic capillary damage are probably involved. Acute blood loss, particularly from gastrointestinal in a patient already suffering from chronic iron-deficiency anemia, can produce profound visual loss often several days later. Pernicious anemia is due to vitamin B 12 deficiency. In addition to anemic retinopathy, optic neuropathy may occur. Platelet deficiency diseases cause a retinopathy, similar to that of severe anemia, with retinal hemorrhages, edema, and cotton-wool spots. Bleeding from iris vessels may cause recurrent hyphemas.