Neovascular glaucoma treatment is for the control of abnormal blood vessel growth, treatment of retinal ischaemia and reduction of high eye pressure which in turn helps to prevent further optic nerve damage. Diabetes, especially in cases of advanced diabetic retinopathy, is a very important cause. Severe eye pain, redness, blurred vision or sudden vision loss is a sign of advanced disease which requires prompt ophthalmic assessment.
What Is Neovascular Glaucoma?
Neovascular glaucoma which is a serious type of secondary glaucoma. There are reports of abnormal new blood vessels that have developed on the iris and in the eye’s drainage angle. Also what doctors may refer to as rubeotic glaucoma.
These delicate structures may develop fibrovascular tissue that over time blocks aqueous humor outflow. Eye pressure goes up which in turn may damage the optic nerve. In early neovascular glaucoma treatment we aim to both the abnormal vessels and the intraocular pressure.
How Does Diabetes Cause Neovascular Glaucoma?
A long course of diabetes may cause damage to retinal blood vessels and reduce the oxygen delivery to retinal tissue. In advanced diabetic eye disease, especially in the case of proliferative diabetic retinopathy, there is production of large amounts of vascular endothelial growth factor which is also known as VEGF.
VEGF promotes new blood vessel growth. In diabetic neovascular glaucoma which is a complication of diabetes these vessels may extend onto the iris and drainage angle. This process which in turn causes secondary glaucoma diabetes and is associated with retinal ischaemia.
The National Diabetes Retinopathy Survey reported that 16.9% of Indian diabetics over the age of 50 reported retinopathy. Also 3.6% of them had sight threatening retinopathy. This is important as in advanced retinal ischaemia we see the development of diabetic neovascular glaucoma.
Other causes include central retinal vein occlusion and ocular ischaemic syndrome. Proliferative diabetic retinopathy remains an important cause linked with diabetes.
| Risk factor or cause | How it contributes | Clinical concern |
| Proliferative diabetic retinopathy | Causes severe retinal ischaemia and VEGF release | Major risk for diabetic neovascular glaucoma |
| Retinal vein occlusion | Reduces retinal blood flow | May trigger iris neovascularisation |
| Ocular ischaemic syndrome | Restricts ocular circulation | Can cause rubeotic glaucoma |
| Poorly controlled diabetes | Promotes retinal vascular damage | Increases risk of advanced diabetic eye disease |
Neovascular Glaucoma Symptoms to Watch For
Early in the development of abnormal iris blood vessels there may be few noticeable symptoms. As pressure in the eye increases, neovascular glaucoma symptoms present themselves more so. They include blurred vision, redness, eye discomfort, headache and reduced vision.
Advanced in its aggressive form, neovascular glaucoma symptoms may present with very painful eyes, very red eyes, halos around light, nausea and large scale visual impairment. Rubeotic glaucoma at its advanced stage may present with very little eye outflow due to scarring of the drainage angle. Any sudden loss of vision, very painful eyes or rapidly deteriorating sight require immediate assessment. These symptoms should not wait for a routine appointment.
How Is Neovascular Glaucoma Diagnosed?
Diagnosis includes ophthalmoscopic examination of the front and back of the eye. With the slit lamp we are able to see abnormal iris blood vessels. Gonioscopy is used to identify abnormal vessels or closure in the drainage angle. Tonometry measures intraocular pressure. Dilated retina exam can point out diabetic retinopathy, vein occlusion or other retinal ischaemia. Also we use OCT and other retinal imaging to get additional structural info.
An evaluation of the optic nerve is also important which is true because of permanent damage that raised pressure may cause. As for the conditions like optic disc drusen which may alter the appearance of the optic nerve or visual fields we see though they do not cause neovascular glaucoma.
| Test | What it checks | Why it matters |
| Slit-lamp examination | Iris and anterior eye structures | Detects new iris vessels |
| Gonioscopy | Drainage angle | Identifies angle neovascularisation or closure |
| Tonometry | Intraocular pressure | Measures pressure elevation |
| Dilated retinal examination | Retina and retinal circulation | Finds the underlying ischaemic disease |
| OCT/optic nerve assessment | Retina and optic nerve | Assesses structural damage |
What Does Neovascular Glaucoma Treatment Involve?
Neovascular glaucoma treatment typically has a multi modality approach. We aim first at reducing the cause of abnormal blood vessel growth. Second we aim at lowering intraocular pressure and at preserving what is left of the optic nerve function.
Anti-VEGF Treatment
An anti VEGF injection will put a stop to VEGF action and that in turn may cause abnormal iris vessels to go back to normal fast. Also we see that in anti VEGF neovascular glaucoma a short term or bridge therapy of anti VEGF works very well.
That said, anti VEGF is not a standalone solution for the underlying retinal ischaemia. We see that evidence in favor of anti-VEGF is as an add on to the total neovascular glaucoma treatment instead of a stand-in for retina treatment.
Retinal Laser Treatment
Panretinal photocoagulation addresses areas of severely ischaemic retina and reduces the current stimulus for abnormal vessels. It still is an important element in the neovascular glaucoma treatment when retinal conditions allow laser therapy.
Eye-Pressure Treatment and Surgery
Pressure reducing eye drops are a part of the treatment. If pressure is not responsive, an ophthalmologist may do drainage device surgery, trabeculectomy in some cases or cyclodestructive procedures.
A in depth glaucoma eye test may look at pressure, optic nerve health and visual function. What treatment is chosen is based on disease stage, remaining vision, retinal status and angle condition.
Can Diabetic Neovascular Glaucoma Be Prevented?
Not everything can be prevented. But we see that which which does not at large is controlling diabetes and early detection of retinopathy before it progresses into severe retinal ischaemia can reduce that risk which is avoidable. People with diabetes should go for retinal screening as the health care professionals advise, even if your vision seems to be fine. In the early stages of proliferative disease management which in turn also look at the retina may help to reduce the stimulus that drives secondary glaucoma diabetes complications.
Eye Care at Vasan Eye Care
Vasan Eye Care which does evaluation for diabetic retinal disease and secondary glaucoma. Based on what we see we may recommend retinal imaging, pressure measurement, gonioscopy, anti-VEGF therapy, laser treatment or glaucoma surgery. It is important to have an early assessment when neovascular glaucoma symptoms appear because by the time damage to the optic nerve has taken place it may not be reversed.
Frequently Asked Questions
1. Is neovascular glaucoma caused only by diabetes?
No. Diabetes is a major cause but retinal vein occlusion and ocular ischaemic syndrome also play a role in the development of rubeotic glaucoma. All of these conditions which in turn reduce retinal oxygen supply and produce abnormal blood vessel growth.
2. Does an anti-VEGF injection cure neovascular glaucoma?
No. An anti VEGF injection will stop abnormal vessels from growing, although not always permanently. Anti VEGF in the case of neovascular glaucoma usually is used in association with retinal laser, pressure reducing medicine or surgery.
3. Can diabetic neovascular glaucoma cause permanent vision loss?
Yes. Diabetic neovascular glaucoma may damage the optic nerve if intraocular pressure is high. Also diabetic retinopathy may cause vision problems. For early intervention we do have treatment that aims at preserving what little site is remaining as well as preventing progression of damage.
4. When should neovascular glaucoma symptoms be treated as urgent?
Severe ocular pain, intense redness, sudden change in vision, halos, nausea or rapid onset of neovascular glaucoma symptoms require prompt ophthalmic evaluation. Urgent care will identify very high eye pressure or another serious retinal issue.
References
- Prevalence of Diabetic Retinopathy in India: Results From the National Survey 2015–19
https://pubmed.ncbi.nlm.nih.gov/34708747/ - Updates in the Treatment of Neovascular Glaucoma: From Conventional Approaches to Novel Therapies
https://pubmed.ncbi.nlm.nih.gov/40995895/