[Features associated with retinal thickness extension in diabetic macular oedema]

Clinically significant macular edema has features that are associated with a major risk of visual loss, with thickening that involves the centre of the macula, field 7 or visual deficiency, although it is unknown if these features are related to retinal thickness extension.

An observational, analytical, prospective, cross-sectional and open study was conducted. The sample was divided into initial visual acuity ≥0.5, central field thickness, center point thickness, field 7 and macular volume more than the reported 2 standard deviation mean value in eyes without retinopathy. The extension was determined by the number of the central field area equivalent thickening and these features were compared with by Student's t test for independent samples.

A total of 199 eyes were included. In eyes with visual acuity of ≥0.5, the mean extension was 2.88±1.68 and 3.2±1.63 in area equivalent in eyes with visual acuity <0.5 (p=0.12). The mean extension in eyes with less than 2 standard deviation of central field thickness, center point thickness, field 7 and macular volume was significantly lower than in eyes with more than 2 standard deviations (1.9±0.93 vs. 4.07±1.49, 2.44±1.47 vs. 3.94±1.52, 1.79±1.07 vs. 3.61±1.57 and 1.6±0.9 vs. 3.9±1.4, respectively, p<0.001).

The extension of retinal thickness is related with the anatomical features reported with a greater risk of visual loss, but is not related to initial visual deficiency.