Abstract
Abstract: :
Purpose: Serous macular detachments (SMD) occur in some cases of macular edema but the effect of SMD on visual function is unknown. Our aim was to assess the relationship between visual acuity (VA), macular morphology, certain risk factors and the occurrence of SMD in patients with diabetic macular edema. Methods: In a retrospective observational study we examined 200 eyes of 126 patients with diabetic macular edema by optical coherence tomography (OCT). All patients underwent a complete ophthalmologic evaluation, including best corrected Snellen visual acuity converted to LogMAR units. OCT was performed using a commercially available device (OCT Model 2000, Zeiss–Humphrey Instruments). Six radial scans were obtained with a length of 6 mm centered on the fovea. Foveal thickness (FT) and macular volume (MV) were assessed by the built–in software of the scanner, and retinal thickness data were compared with the normative database of the software. The presence of diffuse and cystoid edema (DME and CME, respectively) and also SMD was recorded. Exclusion criteria were retinal thickness within the normal range, lack of cooperation, opaque media, any other macular pathology except for diabetic maculopathy, previous pars plana vitrectomy, and retinal photocoagulation within four months prior to the visit. We excluded eyes in which the software did not measure correctly. In cases where automatic FT measurements had a standard deviation of more than 10% we measured FT manually by the software. Diabetes duration longer than 15 years, edema type (CME/DME) and accompanying hypertension were entered in a multiple regression analysis model to find risk factors for the presence of SMD. Results: SMD was detected in 28 eyes (14%). Both FT and MV correlated with LogMAR VA in eyes with SMD as well as in eyes without SMD (p<0.001, both cases). Linear regression showed that eyes with SMD had significantly higher FT and MV values compared to eyes without SMD. Diabetes duration longer than 15 years proved to be a significant risk factor for SMD (p=0.007, OR=2.66, RR=2.32), while edema type or the presence of hypertension had no effect. Conclusions: According to our results eyes with SMD have better visual acuity than eyes with the same FT/MV values but without SMD. The reason for this is unknown, but further studies using ultrahigh resolution techniques may shed light on the morphological changes accompanying SMD formation. However, long diabetes duration seems to influence the evolution of SMD.
Keywords: diabetic retinopathy • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • macula/fovea