[Vitreoretinal surgery in the treatment of neovascular glaucoma]

Neovascular glaucoma develops on a background of ischemic ocular pathologies, such as diabetic eye diseases or central retinal vein occlusion. Development of neovascular membranes in the chamber angle leads to elevated intraocular pressure. Since treatment by cyclodestructive therapy or drainage surgery often fails, we have examined intense antiproliferative surgery as a treatment for advanced neovascular glaucoma.

Thirty-two patients with neovascular glaucoma subsequent to central vein occlusion or advanced diabetic retinopathy underwent antiproliferative surgery, which comprised vitrectomy, panretinal laser treatment and direct laser coagulation of the ciliary processes, followed by silicone oil tamponade. Patients were followed for a minimum of 1 year and as long as 3 years.

After one week following surgery the intraocular pressure (IOP) was normal, ranging from 8 to 21 mm#Hg, in 52% (15/29 eyes), after 3 months the IOP was normal in 50% (16/32 eyes), after 6 months the IOP was normal in 59% (16/27 eyes) and after 1 year the IOP was normal in 72% (18/25 eyes). Of the 10 eyes that lost all sight after the surgery, 7 eyes had a history of central vein occlusion. Hypotony was observed in 6% (2/32) of the eyes 3 months following surgery; after 6 months hypotony was present in 15% (4/27) of the eyes and after 1 year hypotony was present in 12% (3/25) of the eyes.

The theoretical premise of our surgical intervention (antiproliferative surgery) is based on the assumption that laser treatment interrupts the self enhancing pathway of retinal ischemia, release of proliferative factors and increase in intraocular pressure. The silicone oil endotamponade prevents postoperative complications and supports the rapid regression of rubeosis iridis by separating the anterior from the posterior segment.