Lack of Association Between Thiazolidinediones and Macular Edema in Type 2 Diabetes

Abstract

Diabetic macular edema (DME) is one of the main causes of visual impairment in persons with diabetic retinopathy. A small number of case reports have raised the possibility that use of thiazolidinediones, which can cause fluid retention, generally, might exacerbate DME.^1,2 These observations led to physician alerts or label changes by manufacturers in Canada and the United States.^3-6 One report¹ described a patient who developed vision loss and DME after an increase in the dosage of rosiglitazone maleate from 2 to 8 mg/d. After the dosage was reverted to 2 mg/d, the vision of the patient improved and his DME resolved itself. Ryan et al² reported results from a retrospective medical record review of 30 patients who sought care at a single practice of retinal specialists with use of pioglitazone hydrochloride or rosiglitazone and both lower-extremity edema and DME. The authors contended that fluid overload owing to use of thiazolidinediones contributed to DME in at least 19 of 30 patients and that, in 2 patients, there was evidence of a direct cause-and-effect relationship. Finally, a case report⁷ of macular edema being resolved with systemic furosemide suggests that thiazolidinediones may exacerbate macular edema. In a larger study of 292 patients, Shen et al⁸ found no association of rosiglitazone with DME.