Abstract: Neovascular glaucoma (NVG) represents a challenging subtype of secondary glaucoma characterized by the development of abnormal blood vessel growth on the iris and anterior chamber angle. This article provides a comprehensive review of NVG, including its pathophysiology, clinical presentation, diagnostic approaches, treatment modalities, and recent advancements. By delving into the complexities of NVG management, ophthalmologists can optimize patient care and improve outcomes in this sight-threatening condition.

Introduction: Neovascular glaucoma arises secondary to ischemic retinal conditions such as proliferative diabetic retinopathy (PDR), retinal vein occlusion (RVO), or ocular ischemic syndrome (OIS). The hallmark feature of NVG is the presence of abnormal neovascularization on the iris and anterior chamber angle, leading to secondary angle closure, elevated intraocular pressure (IOP), and subsequent optic nerve damage.

Pathogenesis: Neovascularization in NVG results from ischemic retinal conditions triggering the release of angiogenic factors, such as vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF). These factors promote the formation of abnormal blood vessels on the iris and angle, leading to angle closure, trabecular meshwork obstruction, and increased aqueous outflow resistance.

Clinical Presentation: Patients with NVG typically present with signs of elevated IOP, including optic nerve cupping, visual field defects, and characteristic changes on anterior segment examination. Concurrent features of underlying retinal ischemia, such as neovascularization elsewhere (NVE), vitreous hemorrhage, or retinal detachment, may aid in diagnosing the underlying cause of NVG and guiding management decisions.

Diagnostic Approaches: Diagnosis of NVG involves a comprehensive ocular examination, including measurement of IOP, assessment of optic nerve morphology, visual field testing, and anterior segment imaging. Ancillary tests such as gonioscopy, ultrasound biomicroscopy (UBM), or optical coherence tomography angiography (OCT-A) may be valuable in evaluating angle structures and identifying neovascularization.

Treatment Strategies: Management of NVG aims to reduce IOP, control neovascularization, and preserve visual function. Treatment modalities may include medical therapy to lower IOP, panretinal photocoagulation (PRP) to induce regression of neovascularization, and surgical interventions such as trabeculectomy or glaucoma drainage devices for refractory cases. Combination therapy may be necessary to achieve optimal outcomes in NVG management.

Recent Innovations: Recent advancements in NVG management focus on targeted antiangiogenic therapy, minimally invasive glaucoma surgery (MIGS) devices, and adjunctive measures to improve treatment efficacy and safety. Novel anti-VEGF agents such as aflibercept and conbercept offer potential benefits in reducing neovascularization and improving visual outcomes in NVG. Additionally, microinvasive procedures such as endoscopic cyclophotocoagulation (ECP) or transscleral diode laser photocoagulation (TSCPC) provide alternative options for IOP control in NVG.

Conclusion: Neovascular glaucoma represents a complex and challenging condition requiring a multidisciplinary approach to management. By staying informed about the latest research and innovations in NVG treatment, ophthalmologists can optimize patient outcomes and improve quality of life for individuals affected by this sight-threatening condition.

For further reading and reference:

• American Academy of Ophthalmology – Neovascular Glaucoma: https://www.aao.org/eye-health/diseases/neovascular-glaucoma
• Glaucoma Research Foundation – Neovascular Glaucoma: https://www.glaucoma.org/glaucoma/neovascular-glaucoma.php
• National Eye Institute – Glaucoma: https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/glaucoma