Optical coherence tomography findings in diabetic macular edema before and after vitrectomy

To assess the role of optical coherence tomography (OCT) in the evaluation and follow-up after vitrectomy for diabetic macular edema.

The 18 eyes of 12 patients affected by presumed diabetic vitreous-induced macular edema underwent biomicroscopy with a Goldmann contact lens, fluorescein angiography, and OCT.

OCT revealed two patterns of edema. The first group (15 eyes) was characterized by widespread thickening of the neurosensory retina with an increased nonhomogeneous reflectivity of the inner retinal layers; cystoid-like spaces of absent or reduced reflectivity in the neurosensory retina were also present. In the second group (3 eyes), a cystoid macular edema with a dome-shaped foveal profile because of a markedly increased retinal thickness in the foveal region was observed. The disappearance of the physiologic foveal profile was always seen. Biomicroscopy revealed an increased reflex of the inner limiting membrane in the first group and minimal alterations in the second one. Four patients (7 eyes) underwent vitrectomy with posterior hyaloid removal. In 5 eyes, the patients experienced a visual improvement greater than two Snellen lines. The restoration of the normal foveal profile and the reduction of the retinal thickness on the OCT were evident in all cases one month after surgery.

OCT appears to be a useful tool in the diagnosis and management of diabetic macular edema and in the monitoring of the morphological changes after vitrectomy.