Bariatric surgery induces an instant normalisation of blood glucose in as many as 80% of patients with type 2 diabetes. It has been previously reported that diabetic retinopathy (DR) is stable within one year after bariatric surgery. In this study, 51 patients with type 2 diabetes were examined, two weeks before and one, three, six and 12 months after bariatric surgery. Retinal thickness was measured with optical coherence tomography and automated segmentation in the fovea, parafovea and perifovea in each retinal layer. Retinal vessels were measured in a zone 0.5–1 disc diameters from the optic disc. The total macula thickened with a peak after six months in both univariate and multivariate analysis. The thickening was most prominent in the parafoveal ring 1-3mm from the centre and in the retinal nerve ﬁbre layer and outer nuclear layer. A fall in HbA 1c (p=0.01) and longer duration of diabetes (p=0.01) were associated with more thickening. The study concluded that patients with type 2 diabetes had thickening of the retina after gastric bypass surgery with a peak six months postoperatively. The thickening was most pronounced in the retinal nerve ﬁbre layer and the outer nuclear layer of the parafovea. In multivariate analysis, there was an increase in central retinal artery equivalent at 12 months.