VEGF concentration correlates to foveal thickness

The concentration of vascular endothelial growth factor (VEGF) in the vitreous is associated with the mean thickness of the fovea as measured by optical coherence tomography (OCT), according to study results published online ahead of print by Investigative Ophthalmology & Visual Science.

Hiroyuki Shimada of Nihon University, Tokyo, Japan and colleagues collected vitreous samples from the premacular vitreous and either the mid-vitreous (n=35, Group A) or the peripheral cortical vitreous (n=36, Group B) of diabetic macular oedema (DME) patients who had no posterior vitreous detachment and no previous panretinal photocoagulation. The team then used OCT to measure the mean foveal thickness and enzyme-linked immunosorbent assay to measure vitreous VEGF levels, and compared the results with those taken from the control group: eyes with stage 3 macular hole (n=10).

In the DME eyes, the mean concentration of VEGF in the premacular vitreous was 1386.2 pg/ml, with a standard deviation of 2134.1 pg/ml; in the peripheral cortical vitreous, the mean was 1169.7 pg/ml (SD=1840.3 pg/ml), and in the mid-vitreous, the mean concentration was 1080.9 pg/ml (SD=1534.1 pg/ml). In the control group, VEGF concentrations were below 20 pg/ml for each of the three measurement sites. The mean foveal thickness correlated to concentrations of VEGF at each of the areas of the vitreous tested.

The researchers concluded that, because of the correlation of foveal thickness and VEGF concentration, and the higher concentration of VEGF in the premacular vitreous when compared with the mid-vitreous and peripheral cortical vitreous, it is likely in DME eyes that VEGF is diffused from the macular to the periphery and from the posterior to the anterior globe.