Changes of aqueous vascular endothelial growth factor and interleukin-6 after intravitreal triamcinolone for branch retinal vein occlusion.

BACKGROUND

To investigate sequential changes of aqueous vascular endothelial growth factor (VEGF) and interleukin (IL)-6 in macular oedema secondary to branch retinal vein occlusion after single intravitreal injection of triamcinolone acetonide (IVTA).

METHODS

We recruited 10 healthy controls and 30 patients at Chonnam National University Hospital, Gwangju, Korea. Aqueous and plasma levels of VEGF and IL-6 were measured by enzyme-linked immunosorbent assay at the time of IVTA and 3 months later. Non-response to IVTA was defined as showing persistent macular oedema based on a reduction of central macular thickness by less than 20% from baseline measurements by optical coherence tomography and vision improvement by less than 0.3 logMAR. Fluorescein angiography was performed 6 months after IVTA. We compared aqueous levels of VEGF and IL-6 between responders and non-responders.

RESULTS

The aqueous levels of VEGF and IL-6 were significantly higher in 12 non-responders than in 18 responders at baseline measurements (511 +/- 245 pg/mL vs. 230 +/- 108 pg/mL, P < 0.001; 38 +/- 31 pg/mL vs. 16 +/- 13 pg/mL, P < 0.001, respectively). Aqueous levels of VEGF were still higher in non-responders (312 +/- 64 pg/mL) 3 months after IVTA, and aqueous levels of VEGF in responders returned to normal (86 +/- 21 pg/mL, P < 0.001). Aqueous levels of IL-6 normalized in all patients 3 months after IVTA. Fluorescein angiography revealed that non-responders showed higher frequencies of macular ischaemia and ischaemic branch retinal vein occlusion.

CONCLUSIONS

IL-6-independent VEGF secretion may contribute to persistent macular oedema associated with ischaemic BRVO after IVTA.