No abstract

OBJECTIVEBy correlating known diabetes duration with the prevalence of retinopathy, more than 10 years have been estimated to lapse between the onset and diagnosis of type 2 diabetes. Such calculations, however, assumed a linear model, included stages of retinopathy not specific to diabetes, and allowed 5 years for retinopathy to occur after the onset of diabetes. We calculated the duration of undiagnosed type 2 diabetes in outpatients screened for retinopathy in a hospital-based diabetes clinic after correcting these assumptions. RESEARCH DESIGN AND METHODSDiabetic patients (n = 12,074; 35,545 fundus examinations) were stratified into younger onset (YO; age at onset <30 years) or older onset (OO; age at onset ‡30 years), insulin treated (IT) or not IT (NIT), and with mild/more severe diabetic retinopathy (AnyDR) or moderate/more severe diabetic retinopathy (ModDR). The best-fitting equation correlating known duration among the OO-NIT group with the prevalence of ModDR was used to extrapolate time from appearance of retinopathy to diagnosis of type 2 diabetes. Time for retinopathy to develop after diabetes was calculated from the equation correlating the duration among the YO-IT group with appearance of ModDR. RESULTSThere were 1,719 patients in the OO-NIT group with AnyDR and 685 with ModDR and 756 in the YO-IT group with AnyDR and 385 with ModDR. A linear model showed ModDR appeared 2.66 years before diagnosis among those in the OO-NIT group. A quadratic model suggested that ModDR appeared 3.29 years after diagnosis among those in the YO-IT group. The resulting estimate was 6.05 years (2.66 + 3.29) between the onset and diagnosis of diabetes, compared with 13.36 years using standard criteria. CONCLUSIONSUsing best-fitting models and stratifying by glucose-lowering treatment and severity of retinopathy substantially lowers the estimated duration of undiagnosed type 2 diabetes.

Cystoid retinal degeneration in eyes with chronic CSC was distributed outside of the fovea and was not necessarily associated with severely reduced visual acuity. "Posterior cystoid retinal degeneration" defines this pathologic pattern appropriately. OCT findings suggest that intraretinal exudation and cystoid changes in chronic CSC develop through the formation of chorioretinal adherences.

Disease duration longer than 5 years and subretinal fibrosis are associated with the development of PCRD in CSC. Prospective evaluations could substantiate the associations found in this study and further clarify their significance.