Alteration of the Balance between Vascular Endothelial Growth Factor and Endostatin in Vitreous after Vitrectomy in Patients with Proliferative Diabetic Retinopathy

1. Shigeo Yoshida¹
2. Keijiro Ishikawa¹
3. Yukio Sassa²
4. Ryo Asato²
5. Toshihiro Kono²
6. Tatsuro Ishibashi¹

¹Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.
²Fukuoka University Chikushi Hospital, Fukuoka, Japan.

Purpose: The purpose of this study was to determine whether vitrectomy alters the concentration of vascular endothelial growth factor and endostatin in the vitreous of eyes with proliferative diabetic retinopathy (PDR).

Methods: We measured the levels of VEGF and endostatin by sandwich enzyme linked immunosorbent assay (ELISA) in vitreous samples from 39 eyes of 33 patients with PDR before pars plana vitrectomy (without IOL implantation) and 39 fluid samples from the same patients with PDR obtained during an IOL implantation 3.1 to 25.7 (mean 6.7) months after an earlier vitrectomy. The levels of those factors were also measured in 36 vitreous samples obtained from 36 eyes that had undergone epiretinal membrane (ERM) or macular hole (MH) surgeries.

Results: The mean vitreous levels of VEGF in the sample from eyes with PDR collected at the IOL implantation were significantly lower than in those collected before the vitrectomy (P <0.01). On the other hand, there was no significant difference in the endostatin level among the vitreous samples from the patients with PDR, from patients collected at the time of the IOL implantation and controls.

Conclusion: The results suggest that vitrectomy shifts the eye towards an anti-angiogenic environment. This may partly explain why vitrectomy is effective in reducing the activity of the retinopathy in eyes with PDR.