The effect of perifoveolar posterior vitreous detachment on diabetic macular edema assessed by Optical Coherence Tomography (OCT).

Abstract

Abstract: : Purpose: To establish with OCT whether or not perifoveolar posterior vitreous detachment (PVD) affect the profile of retinal thickening in diabetic macular edema. Methods: Forty–seven eyes of 41 consecutive diabetic patients with macular edema were included in this study. Six scans 6 mm long, forming a radial spoke pattern centered on the patient’s fixation point were performed on each eye. Eyes were classified according to vitreous detachment, into 2 groups: perifoveolar PVD and others. Retinal thickness was measured at the center of macula and at the borders of the scans, 3 mm from the center. OCT scans were also qualitatively analyzed. Results: The mean age of patients (23 males and18 females) was 63 years. Nineteen eyes (40%) had perifoveolar PVD, and 28 (60%) did not. No case of tractional edema associated with a thickened taut posterior hyaloid was observed. In the perifoveolar PVD group the macula was typically dome–shaped, whereas in others it was more homogeneously thickened. The ratio of central macular thickness to mean border thickness was 2.02±0.34 in the perifoveolar PVD group versus 1.58±0.46 in the others (p=0.0007). Conclusions: The role of the traction exerted by the vitreous on the macula in the pathogenesis of diabetic macular edema remains controversial. Vitreous traction on the macula, if any, may be maximal during perifoveolar PVD, because it is concentrated on a small surface of the macula. The present study showed that the ratio of central macular thickness to the thickness 3 mm from the center was significantly greater in eyes with perifoveolar PVD than in others. In diabetic macular edema, perifoveolar PVD seems to increase the thickness of the retina in the center of the macula, to which the vitreous is attached.

Keywords: diabetic retinopathy • retina • vitreous