[Treatment of retinopathy of incontinentia pigmenti by anti-vascular endothelial growth factor]

Effect of Conbercept on Corneal Neovascularization in a Rabbit Model

OBJECTIVE

To study the efficacy of Conbercept for the treatment of corneal neovascularization (NV) in a rabbit model.

METHODS

NV was induced by placing sutures. Eight rabbits were used as a control. The other 136 rabbits were randomly divided into two equal groups, and 68 rabbits in each group were divided into four subgroups and given different treatments. Time-course photographs, histological examination, and enzyme-linked immunoassay ELISA analysis for vascular endothelial growth factor were performed at weeks 1, 2, and 3 after injection placement.

RESULTS

At weeks 1, 2, and 3 after injection placement, there was less expression of corneal NV and VEGF in the conbercept-treated groups than in the saline-treated control groups and less corneal NV and VEGF were expressed in the early treatment group than in the late treatment group. At weeks 2 and 3 after injection, there were fewer corneal NV (length and area) in the early intrastromal injection group with conbercept than in the early subconjunctival injection group with conbercept and a smaller diameter of corneal NV than in the late intrastromal injection group treated with conbercept. Histological examination showed a smaller diameter of corneal NV in all eyes in conbercept-treated groups 1 w after injection than before injection. Treatment with subconjunctival injection with conbercept led to a larger diameter at weeks 2 and 3 than at week 1.

CONCLUSIONS

Subconjunctival and intrastromal administrations of conbercept effectively inhibit corneal NV in rabbits, and the latter has the better effect. The effect is the best in the group with cornea intrastromal injection of conbercept 1 w after suture. Early administration of conbercept may successfully inhibit corneal NV in an animal model.

Case Report: A Case of Cotton-Wool Spots After Intravitreal Injection of Conbercept in an Infant With Incontinentia Pigmenti

Introduction: Incontinentia pigmenti (IP) is a rare X-linked neuroectodermal dysplasia affecting multiple organs. One of its most significant ophthalmic manifestations is retinal neovascularization due to retinal ischemia, which has been traditionally treated with laser photocoagulation or cryotherapy. The application of anti-vascular endothelial growth factor (VEGF) has been reported for the treatment of retinopathy of IP with beneficial results. However, clinicians should be aware of the possible ocular and systemic side effects of the intravitreal injection of anti-VEGF agents.

Case Report: A 4-month-old female infant with IP was treated with intravitreal injection of conbercept in both eyes. However, cotton-wool spots were noticed in the left eye 1 week after the injection. Laser photocoagulation was performed as an adjunct treatment. The cotton-wool spots were absorbed 1 month after the first intravitreal injection and have eventually disappeared.

Discussion: The cotton-wool spots, after intravitreal injection of conbercept for the treatment of IP, indicated severe retinal ischemia resulting from the neutralization of excessive VEGF, which was shown on fundus photograph and fluorescent angiography. Anti-VEGF agents could cause retinal arteriolar vasoconstriction and artery occlusion on rare occasions. The administration of anti-VEGF agents in pediatric cases with severe neovascularization and retinal ischemia should be carefully considered.