Histoplathology and regression of retinal hard exudates in diabetic retinopathy after reduction of elevated serum lipid levels

Purpose: To describe a regression of retinal hard exudates in 2 patients with diabetic maculopathy, and to report immunohistologic findings reflecting lipid deposition in the retina. Design: Two interventional case reports. Methods: Two patients with exudative diabetic maculopathy were treated to normalize serum lipids. Histologic examination and immunohistochemistry of each patient's eyes were performed to assess the localization of apolipoprotein B and cholesteryl ester, both of which are principal components of low-density lipoprotein. Results: Both patients showed a dramatic regression of retinal hard exudates after correction of dyslipidemia. Histopathology revealed diffuse lipids and cholesteryl ester in the retina. Apolipoprotein B and macrophages were colocalized in the perivascular space. Conclusions: The regression of hard exudates was most likely due to the aggressive lipid lowering in both patients. The novel histopathologic findings of hard exudate and diabetic maculopathy are similar to the pathologic changes observed in larger atherosclerotic lesions, except that they occur in the intraretinal perivascular space. (C) 2003 by the American Academy of Ophthalmology.