To characterize the expression of vascular endothelial growth factor (VEGF) in a patient with retinopathy of prematurity (ROP) treated with ranibizumab (Case 1) and compare it with a case of ROP without treatment (Case 2), a case of a premature baby without ROP (Case 3), and a case of a baby without history of ROP or prematurity (Case 4).

Observational case series.

The eyes of the deceased babies were removed postmortem and were sent to the Florida Lions Ocular Pathology Laboratory, where they were processed. The specimens were immunostained using an antibody against VEGF.

All eyes except for the eyes in Case 4 disclosed positive VEGF staining. Positive staining was present within the nerve fiber layer, inner plexiform layer, and inner and outer nuclear layers and within the spindle-shaped cell population in the vanguard in Case 1. In the posterior pole, positive staining was only observed at the level of the nerve fiber layer. This case also demonstrated less positive staining when compared with Case 2, where positive staining was found within all layers of the retina.

Less VEGF staining was observed within the retina of the eyes treated with ranibizumab when compared with the VEGF staining in Case 2. This supports the idea that anti-VEGF agents are effective in reducing the amount of VEGF present in the retina. Furthermore, the fact that some expression of VEGF remains in the immature retina after injection supports the idea that anti-VEGF agents can suppress uncontrolled neovascularization without completely blocking the vascular drive for the vascularization of the immature retina.