These blood vessels eventually go through a process called fibrosis which closes the normal physiologic anatomy of the angle.

The closing of the angle prevents fluid from leaving the eye resulting in an increase in intraocular pressure.

The injection blocks the direct effect of VEGF and acts more quickly but will wear off in about six weeks.

Once the neovascularization has been longstanding, the new vessels recruit fibrous tissue, and as this forms and contracts, the angle can be permanently damaged, and will not respond to treatment.

If this occurs, then surgical intervention is required to reduce the pressure (such as a glaucoma drainage implant)