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PubMed This is a summary of 15 peer-reviewed journal articles Updated
Ophthalmology

Understanding Your Diagnosis: Neovascular Glaucoma

At a Glance

Neovascular glaucoma (NVG) is a serious eye condition where oxygen deprivation—often from diabetes or an eye stroke—causes abnormal blood vessels to grow. These vessels block the eye's drainage system, causing painful pressure spikes. Prompt treatment with anti-VEGF injections can stabilize it.

It is completely normal to feel overwhelmed or even panicked right now. Neovascular glaucoma (NVG) is a serious and fast-moving condition that often brings sudden pain and frightening changes to your vision [1][2]. While the situation is urgent, it is not a mystery. Your care team is dealing with a known mechanical problem that has a specific biological cause. Understanding how this happened is the first step in taking control of your care.

The “SOS” Signal: Why This Happens

The root of neovascular glaucoma is a lack of oxygen in the back of the eye, a state called ischemia [3][4]. This is usually caused by an underlying health issue, such as advanced diabetes or a “stroke” in the eye (a retinal vein or artery occlusion) [5][6].

When the retina (the light-sensing tissue at the back of the eye) is starved for oxygen, it sends out an “SOS” signal—a protein called VEGF (Vascular Endothelial Growth Factor) [3][7]. This signal’s job is to tell the body to grow new blood vessels to bring in more oxygen. However, these new vessels are fragile, abnormal, and grow in places they don’t belong—specifically, across the front of the eye and into the drainage system [8][9].

A Blocked Drain: The Cause of Pressure Spikes

Your eye constantly produces a clear fluid called aqueous humor, which must drain out at the same rate it is produced to maintain a healthy pressure [8]. In NVG, the abnormal new vessels grow over the trabecular meshwork, which is the eye’s primary drain [10][11].

  1. Phase 1: The Membrane Blockage. Initially, a thin, invisible membrane of these vessels covers the drain. This makes it harder for fluid to leave, causing pressure to begin to rise [8].
  2. Phase 2: The Scarring. Over time, these abnormal vessels and the membrane they create can contract or shrink. This acts like a “zipper,” physically pulling the iris (the colored part of the eye) forward and permanently scarring the drain shut [8][11].

This physical blockage is why the pressure can spike so high and so quickly, leading to the pain and blurred vision you may be experiencing [1][2].

Stabilizing Facts

While the diagnosis is daunting, several key facts can help orient you as you begin treatment:

  • The “SOS” signal can be turned off. Modern medicine has powerful tools called anti-VEGF injections that can rapidly stop the production of the signal and cause the abnormal vessels to shrink [12][13].
  • Treatment is multi-layered. Your doctors will use a combination of therapies—injections to stop vessel growth, lasers (PRP) to reduce the eye’s demand for oxygen, and potentially surgery or specialized drops to manage the pressure [11][14].
  • The goal is stabilization. The immediate priority of your care team is to lower the pressure and stop the cycle of vessel growth to prevent further damage to the optic nerve [15][14].

Understanding that this is a mechanical issue—excess fluid trapped by abnormal growth—helps clarify why your doctors are moving quickly to clear the blockage and address the underlying oxygen shortage [9][11].

Common questions in this guide

What causes neovascular glaucoma?
It is triggered by a lack of oxygen in the back of the eye, often due to advanced diabetes or an eye stroke. The oxygen-starved tissue releases a signal called VEGF, which prompts fragile, abnormal blood vessels to grow and block the eye's drainage system.
Why does neovascular glaucoma cause sudden eye pain?
The abnormal blood vessels grow over the eye's natural drain, preventing fluid from escaping normally. This physical blockage causes fluid to build up rapidly, leading to a sudden and painful spike in eye pressure.
How do anti-VEGF injections help treat this condition?
Anti-VEGF injections block the distress signal that tells the eye to grow new blood vessels. This rapidly stops the abnormal vessel growth and often causes existing new vessels to shrink, helping to stabilize the eye pressure.
What is the goal of laser treatment for neovascular glaucoma?
Laser treatment, or panretinal photocoagulation (PRP), reduces the eye's overall demand for oxygen. By addressing the root cause of oxygen starvation, it helps permanently turn off the signals that cause abnormal blood vessels to grow.
Will I lose my vision from neovascular glaucoma?
While NVG is a serious condition that requires urgent care, modern treatments can effectively stabilize it. Your doctors will work quickly to lower your eye pressure and stop vessel growth to prevent permanent damage to the optic nerve and preserve your remaining vision.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.What is the underlying cause of the oxygen deprivation (ischemia) in my eye, such as diabetes or a vein occlusion?
  2. 2.Is my eye's drainage angle currently 'open' but blocked by vessels, or has it begun to scar and 'close'?
  3. 3.How quickly can we start anti-VEGF injections and laser treatment (PRP) to stop the growth of these new vessels?
  4. 4.What are the realistic goals for my vision and eye pressure over the next few months?
  5. 5.How should we monitor my other eye to ensure this doesn't happen there as well?

Questions For You

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References

References (15)
  1. 1

    Management of Neovascular Glaucoma.

    Lidder AK, Paranjpe V, Lauter AJ

    International ophthalmology clinics 2023; (63(4)):167-183 doi:10.1097/IIO.0000000000000480.

    PMID: 37755450
  2. 2

    Surgical outcomes including visual improvement after glaucoma surgery in patients with neovascular glaucoma.

    Chey JH, Lee CK

    Heliyon 2024; (10(7)):e28938 doi:10.1016/j.heliyon.2024.e28938.

    PMID: 38623239
  3. 3

    Expression of platelet-derived growth factor-C in aqueous humor of patients with neovascular glaucoma and its correlation with vascular endothelial growth factor.

    Li Y, Hu D, Lv P, et al.

    European journal of ophthalmology 2020; (30(3)):500-505 doi:10.1177/1120672119832785.

    PMID: 30803266
  4. 4

    Neovascular glaucoma - A review.

    Senthil S, Dada T, Das T, et al.

    Indian journal of ophthalmology 2021; (69(3)):525-534 doi:10.4103/ijo.IJO_1591_20.

    PMID: 33595466
  5. 5

    Posterior Vitreous Detachment and Risk of Neovascular Glaucoma in Eyes with Prior Retinal Vascular Occlusions.

    Palmer LD, Peterson JD, Evans JK, et al.

    Ophthalmology and therapy 2024; (13(11)):3013-3024 doi:10.1007/s40123-024-01039-1.

    PMID: 39342534
  6. 6

    Trabeculectomy for neovascular glaucoma in proliferative diabetic retinopathy, central retinal vein occlusion, and ocular ischemic syndrome: Surgical outcomes and prognostic factors for failure.

    Senthil S, Chary R, Ali MH, et al.

    Indian journal of ophthalmology 2021; (69(11)):3341-3348 doi:10.4103/ijo.IJO_1516_21.

    PMID: 34708802
  7. 7

    Aqueous Inflammation and Ischemia-Related Biomarkers in Neovascular Glaucoma with Stable Iris Neovascularization.

    Sun C, Zhang H, Tang Y, et al.

    Current eye research 2020; (45(12)):1504-1513 doi:10.1080/02713683.2020.1762226.

    PMID: 32339463
  8. 8

    Etiology, pathogenesis, and diagnosis of neovascular glaucoma.

    Călugăru D, Călugăru M

    International journal of ophthalmology 2022; (15(6)):1005-1010 doi:10.18240/ijo.2022.06.20.

    PMID: 35814894
  9. 9

    [Current views on pathogenesis and treatment of neovascular glaucoma].

    Fedoruk NA

    Vestnik oftalmologii 2024; (140(3)):110-116 doi:10.17116/oftalma2024140031110.

    PMID: 38962986
  10. 10

    Neovascular glaucoma incidence and visual outcomes in treated proliferative diabetic retinopathy with anterior segment neovascularisation.

    Fiddimore E, Al-Janabi A, Sulur Sundararajan R, Gallagher K

    Eye (London, England) 2026; (40(1)):77-82 doi:10.1038/s41433-025-04099-0.

    PMID: 41188570
  11. 11

    Neovascular Glaucoma from Ocular Ischemic Syndrome Treated with Serial Monthly Intravitreal Bevacizumab and Panretinal Photocoagulation: A Case Report.

    Asif H, Si Z, Quan S, et al.

    Case reports in ophthalmological medicine 2022; (2022()):4959522 doi:10.1155/2022/4959522.

    PMID: 35935916
  12. 12

    Predictors of Neovascular Glaucoma in Central Retinal Vein Occlusion.

    Rong AJ, Swaminathan SS, Vanner EA, Parrish RK

    American journal of ophthalmology 2019; (204()):62-69 doi:10.1016/j.ajo.2019.02.038.

    PMID: 30862502
  13. 13

    Central retinal thickness changes and risk of neovascular glaucoma after intravitreal bevacizumab injection in patients with central retinal vein occlusion.

    Lee YH, Kim YC

    Scientific reports 2022; (12(1)):2051 doi:10.1038/s41598-022-06121-x.

    PMID: 35136171
  14. 14

    Early Surgical Intervention for Neovascular Glaucoma in a Patient with Diabetes.

    Husain KA, Alaali H, Alderazi H

    Cureus 2021; (13(6)):e15420 doi:10.7759/cureus.15420.

    PMID: 34113524
  15. 15

    Medical and surgical management of neovascular glaucoma.

    Yun JS, Santina A, Tseng VL

    Current opinion in ophthalmology 2025; (36(5)):434-441 doi:10.1097/ICU.0000000000001151.

    PMID: 40314467

This page provides educational information about neovascular glaucoma and its causes. Always consult your ophthalmologist or eye care specialist for immediate medical advice and treatment of eye pressure spikes.

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