Choroidal neovascularization (CNV) describes abnormal new blood vessels that grow from the choroid beneath the retina and leak fluid or blood, threatening central vision. It is a key feature of several macular diseases.
Causes
The most common cause is wet age‑related macular degeneration, but CNV can also occur in high myopia, inflammatory conditions, angioid streaks, and some inherited retinal disorders.
- These vessels are fragile and prone to leakage and bleeding.
- Resulting fluid and scarring distort the macula and blur central vision.
- Symptoms include distortion (metamorphopsia) and a central dark or grey patch.
- OCT and fluorescein angiography help diagnose and classify CNV.
Treatment
Intravitreal anti‑VEGF injections are the standard treatment, aiming to dry fluid, reduce leakage, and stabilise or improve vision.
- Most patients require a loading phase followed by ongoing monitoring and repeat injections as needed.
- Early detection leads to better visual outcomes.
- Adjunct laser or photodynamic therapy is occasionally used in selected non‑AMD causes.
- Underlying risk factors such as myopia or inflammation also need ongoing management.
