Purpose: To evaluate the efficacy and safety of orally administered sodium fluorescein to stain the clear vitreous before vitrectomy for proliferative diabetic retinopathy (PDR).
Methods: Twenty-two consecutive eyes of 20 patients with PDR and five eyes of five patients with proliferative vitreoretinopathy (PVR) were included. The average patient age was 52 years (range 46–58). Closed pars plana vitrectomy, proliferative membrane peeling and endolaser photocoagulation were performed. Vitreous and blood samples were collected to measure sodium fluorescein concentrations by high pressure liquefied chromatography.
Results: The degree of staining of the clear vitreous was evaluated by colour photographs, videos and the concentration of sodium fluorescein in the vitreous and blood samples. The clear vitreous in all 22 eyes with PDR ranged from slightly to markedly green, but the clear vitreous in five eyes with PVR was not stained with sodium fluorescein. The sodium fluorescein concentration in the vitreous samples ranged from 122 to 282.0 ng/mL and from 64 to 74 ng/mL in the blood samples in patients with diabetes and PVR. No urticaria, nausea or other side-effects developed.
Conclusion: The clear vitreous can be stained markedly green by sodium fluorescein administered 12–16 h before surgery. Surgeons can easily differentiate residual clear vitreous. The stained vitreous may be made more visible by photocoagulation. This method is also helpful in teaching surgical procedures, and fewer side-effects compared with intravenous and intravitreal fluorescein and intravitreal triamcinolone.