Background: To evaluate the surgical efficacy of vitrectomy, with optical coherence tomography, in patients with non-ischemic and ischemic diffuse diabetic macular oedema not responding to laser treatment.
Methods: Ten eyes from nine patients (aged 46.0 +/- 20 years, diabetes duration 12.4 +/- 4 years) operated with vitrectomy for diabetic macular oedema not responding to laser treatment were evaluated before and 6 months postoperatively. Retinal thickness was assessed with optical coherence tomography, OCT, measuring the mean values of the centre of fovea and the second and third concentric rings from foveola. Four patients with type 1 diabetes had ischemic and five patients (6 eyes) with type 2 diabetes had non-ischemic diffuse macular oedema diagnosed on fluorescein angiography (FA). All eyes had an attached vitreous diagnosed on OCT.
Results: Mean foveal thickness for the three concentric rings from centre and out was significantly less 6 months postoperatively 437 +/- 125 vs. 286 +/- 67 microm; p = 0.027, 426 +/- 105 vs. 308 +/- 35 microm; p = 0.019 and 404 +/- 69 microm vs. 318 +/- 29 microm; p = 0.011 respectively. The decrease in foveal thickness was similar for eyes with and without signs of ischemic maculopathy. There was a trend toward improved visual acuity (VA) 6 months after surgery 0.4; range 0.2-0.6 compared to 0.3; range 0.1-0.5 before vitrectomy; p = 0.107).
Conclusion: Vitrectomy seems to be a beneficial treatment for both ischemic and non-ischemic advanced diffuse diabetic macular oedema not responding to laser treatment.