A review of neovascular glaucoma. Etiopathogenesis and treatment.

Abstract

Neovascular glaucoma (NVG) is a type of secondary glaucoma, refractory to treatment, often incurable, with very poor visual prognosis. It is characterized by the appearance of new vessels over the iris and iridocorneal angle and frequently associates the presence of a fibrovascular membrane which limits the aqueous humor outflow from the anterior chamber. The most common causes of NVG are: central retinal vein occlusion, proliferative diabetic retinopathy, and ocular ischemic syndrome. Once the gonioscopy developed as a part of clinical examination, it became possible to visualize the new vessels of the anterior segment of the eye in early stages and to understand the mechanisms of increased intraocular pressure (IOP), including narrowing and closing of the iridocorneal angle. Also, the modern imaging techniques, such as optical coherence tomography angiography and fluorescein angiography became indispensable for the clinician. Thus, an early diagnosis, followed by starting an appropriate therapy: panretinal photocoagulation or administration of anti-VEGF drugs, with or without hypotensive ocular therapy, allows the preservation of visual functions for patient’s better quality of life. However, one or more surgeries will often be required, especially in the advanced stages of the disease, which do not respond to drug therapy. Managing the NVG we should aim to: 1) reduce ocular ischemia and treat its underlying cause, 2) reduce elevated IOP, once installed and 3) control the inflammatory process. Anyway, the best treatment is prevention, so we must be very attentive at patients with risk factors for developing the NVG. Abbreviations: NVG = neovascular glaucoma, ICA = iridocorneal angle, IOP = intraocular pressure, TM = trabecular meshwork, AH = aqueous humor, AC = anterior chamber, PRP = panretinal photocoagulation, VEGF = vascular endothelial growing factor, Anti-VEGF = anti- vascular endothelial growing factor, PAS = peripheral anterior synechiae, CRVO = central retinal vein occlusion, PDR = proliferative diabetic retinopathy, DR = diabetic retinopathy, OIS = ocular ischemic syndrome, CRAO = central retinal artery occlusion, ROP = retinopathy of prematurity, FEVR = familial exudative vitreoretinopathy, PVR = proliferative vitreoretinopathy, MMPs = matrix metalloproteinases, VEGFR = vascular endothelial growing factor receptor, PDGF = platelet-derived growth factor, PIGF = placental growth factor, NRP = neuropilins, HIF = hypoxia-inducible factor, SDF1 = stromal cell-derived factor 1, DDL4 = delta like ligand 4, NICD = Notch intracellular domain, TIMMPs = tissue inhibitors of matrix metalloproteinases, ANGPT = angiopoietin, Tie 2 = tyrosine-protein kinase receptor for angiopoietins, IGF-1 = insulin-like growth factor 1, RPE = retinal pigment epithelium, IL = interleukin, TNF = tumor necrosis factor, bFGF = basic fibroblast growth factor, TGF = transforming growth factor, HGF = hepatocyte growth factor, TNFR 2 = tumor necrosis factor receptor 2, OIR = oxygen induced retinopathy, NVI =...

The mechanism and therapeutic strategies for neovascular glaucoma secondary to diabetic retinopathy

“…Management of NVG focus on mainly two aspects as shown in Figure 1 : treatment of neovascularization and intraocular pressure. The final goal is to maximize the preservation of visual function with approaches including panretinal photocoagulation (PRP), anti-vascular endothelial growth factor (VEGF) therapy, anti-glaucoma therapy including drug therapy and surgical interventions, management of the systemic disease and intensive follow-up at the same time ( 12 , 51 , 58 , 59 ).…”

“…Ahmed valve consists of a plate, a drainage tube and a valve. Currently, there are at least eleven available models of Ahmed valves depending on single and double plate, pars plana or pars plana pediatric, and others ( 59 ). Numerous studies support that AGV implantation is efficient for refractory glaucoma like NVG ( 59 ).…”

“…Currently, there are at least eleven available models of Ahmed valves depending on single and double plate, pars plana or pars plana pediatric, and others ( 59 ). Numerous studies support that AGV implantation is efficient for refractory glaucoma like NVG ( 59 ). Some may worry about its postoperative complications such as cornea edema, damage of the corneal endothelial cells, exposure of the drainage tube, fibrosis around the plate, etc.…”

Systemic Cytokines in Retinopathy of Prematurity

“…VEGF ligands comprise five members in humans: VEGF-A/B/C/D and placental growth factor (PlGF). They function through three tyrosine kinase cell receptors: VEGFR1, VEGFR2, and VEGFR3 [ 62 ]. Each type of ligand has identical interactions with different receptors, as VEGF-A binds to VEGFR1 and 2, VEGF-B and PlGF only bind to VEGFR1, and VEGF-C and VEGF-D primarily bind to VEGFR3 [ 63 ].…”

Features of hemodynamic and immunological parameters in patients with recurrent uveitis complicated by hypertension, Fuchs heterochromic uveitis and Posner-Schlossman syndrome

“…The mechanisms of acute increase in IOP in patients with uveitis are numerous, and may include structural changes such as blockage of the pupil, iris bombe, causing closure of the angle of the anterior chamber, the formation of peripheral anterior synechia, limiting outflow, displacement of the iris root anteriorly against the background of exudative detachment of the ciliary body, and direct inflammation of the trabecular meshwork, which can lead to the phenomenon previously described as inflammatory ocular hypertension syndrome (IOHS) [ 13 ]. It should be noted that damage to the function of the trabecular meshwork because of a chronic inflammatory process occurs in most cases of intraocular hypertension, and this process is an open-angle type [ 14 - 16 ].…”