Neovascularization Causes Blindness

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Neovascularization Causes Blindness

Neovascularization develops in both macular degeneration and diabetic retinopathy. It is the neovascular tissue, or abnormal blood vessels, that causes blindness and is mediated by VEGF.

Both macular degeneration and diabetic retinopathy can cause “blindness” from neovascularization.  Both are diseases of the retina, both can lead to “blindness,” both increase with age/time and both can be associated with abnormal blood vessel formation known as neovascularization.”

The two diseases differ in the location of the neovascularization.

Diabetic Retinopathy – In cases of diabetic retinopathy, the presence of neovascularization defines a particular stage of eye disease; proliferative diabetic retinopathy.  The neovascularization may “proliferate” along the surface of the retina and other structures inside the eye.  As long as the VEGF is circulating, the vessels will continue to grow.

Diabetic retinal detachments may occur if the the neovascular tissue proliferates out of control.  Neovascular glaucoma may develop if the abnormal blood vessels “clog” the internal drain of the eye.  In this case, intraocular fluid that normally filters out of the eye can no longer escape as the drain is closed.  The pressure escalates out of control and severe pain (and redness) develop.

In short, proliferative diabetic retinopathy, as defined by the presence of neovascularization, can causes retinal detachments and neovascular glaucoma (not the usual form of glaucoma).  Both are mechanisms by which diabetes can cause blindness.

Macular Degeneration – “Wet” macular degeneration, by definition, exists when neovascularization develops underneath the retina.  This neovascular tissue causes physical separation of the layers of the retina and destruction of the normal tissue.  Almost all neovascularization leaks, and, at times, bleeds.  Loss of central vision occurs due to this rather rapid growth of abnormal blood vessels.

VEGF – In either case, neovascular tissue is a complex of “abnormal blood vessels.”  As best we can tell, neovascular tissue develops in response to Vascular Endothelial Growth Factor, or VEGF.  This growth factor causes both proliferation of the neovascular tissue and sustains existing neovascularization.  Without circulating VEGF, the neovascular tissue shrinks up and goes away.

Anti-VEGF treatments are simply directed at blocking the effects of VEGF.

Anti-VEGF medications (e.g. Avastin, Lucentis and Macugen) are antibody like molecules that find circulating VEGF and prevent VEGF from “doing its duty.”   The treatment of choice for proliferative diabetic retinopathy remains pan-retinal photocoagulation (PRP).  The end result of PRP is decreased … VEGF.

With timely diagnosis, both diseases can usually be controlled.  Neovascularization in diabetes can be reversed before a retinal detachment is formed, neovascular glaucoma may be reversed and “wet” macular degeneration can be halted.

What Does This Mean? A few years ago, I would not have been able to write this article.  We have learned a lot about the mechanisms by which both diabetic retinopathy and macular degeneration cause blindness.  It amazes me how the pathogenesis (i.e. the disease process) of both diseases are so similar.  Both diseases can cause blindness via VEGF.

This is why it is so confusing.  Two separate diseases that respond to the same treatment.

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Comments
  • Russ May 1, 2010 at 5:58 pm

    I have Idiopathic juxtafoveolar retinal telangiectasia and it seems Eerily similar to what you are talking about. Do you you have any experience with JFT disease?

    • Randall V. Wong, M.D. May 21, 2010 at 5:10 pm

      I am sorry for the extreme delay. I, uh, let this get buried and forgot.

      JFT is actually not too uncommon. My best results are usually with laser, but especially when the area requiring treatment is far away from the fovea (macula). Steroids have also been helpful.

      If your vision is not affected, you are in good shape.

      Again, sorry.

      r

  • John Bachor June 24, 2010 at 10:41 am

    I have JFT, my vision is about 20/120 in both eyes. I was told by my doctor that it could be caused by a toxin. I was in Vietnam and had very strong contact with Agent Orange. Could there be a link here? any information would be greatly appreciated. Thank You

    • Randall V. Wong, M.D. June 25, 2010 at 3:53 am

      John,

      I have never heard that JFT is caused by anything other than abnormal leaky blood vessels. The exact cause is unknown. The full name is “idiopathic juxtafoveal telangiectasia.” Idiopathic means of unknown cause or origin.

      Hope this was at least slightly helpful.

      Randy

  • Darlene October 13, 2010 at 11:40 am

    I have JFT in my right eye. Sight has steadily gone downhill over the last year. Now my left eye has minimal leakage. My dr has suggested a course of avastin injections for the right eye and has said that its time to do them or I will loose my sight very soon. From what I hear, this is a relatively new treatment. Im wondering what your opinion is concerning these injections for JFT.. Thanks!

    • Randall V. Wong, M.D. October 13, 2010 at 12:40 pm

      Dear Darlene,

      The old treatment used to be laser treatment to the retina. It didn’t work real well. Presently, I recommend, to my patients, either steroids or Avastin. While the treatments are “new,” they have been in use for several years. In many areas, use of Avastin is standard of care so I wouldn’t necessarily view Avastin as experimental.

      Best of luck. Let us know how you do!

      Randy

  • Alison McAllister January 15, 2011 at 12:47 pm

    Dr. Wong I know research is always discovering new things. I saw a news piece that discussed reversing blindness. I wasn’t sure how diabetics were affected. My father-in-law is an insulin dependent diabetic. He was a carpenter and initially when he started losing his sight he had surgery. It became worse. Two days he lost all his vision. He indicates it hurts. What should we do? Our resources are limited what should we ask our where should we take him? We live in Jacksonville NC. Thank you for your article.

    • Randall V. Wong, M.D. January 17, 2011 at 10:40 pm

      Dear Alison,

      In medicine we have a saying..”if you here hoofbeats….don’t think of zebras.”

      Having said that, I think you should make sure that your father-in-laws loss of vision and pain is not related to advanced diabetic retinopathy. It is quite likely that your FIL is suffering from neovascular complications of diabetic retinopathy.

      To be most efficient, I’d have him examined by a retina specialist.

      Best of luck,

      Randy

  • Albert T. June 13, 2011 at 8:37 pm

    Do you know of any links between Agent Orange and blindness. I had a stroke in my right optic nerve in 2002 and since then I have lost most of my vision in my left eye. The doctors say that there are no signs of diabetes causing the blindness. I was exposed to Agent Orange from 1966 to 1968 in Viet Nam. I have insulin depentent DM II, and have been treated for CAD and had four stents inserted. I would like to know why I am going blnd. Please help or guide me to someone who can. Thank you.

    • Randall V. Wong, M.D. June 14, 2011 at 7:56 am

      Dear Albert,

      I am not aware of any association of eye disease with Agent Orange.

      Your biggest risk factors for your problems are the DM and the associated CAD I would think. If, by stroke, you mean ischemic optic neuropathy, please keep in mind that this happens in healthy situations, too.

      Randy

  • Dan Kachermeyer December 2, 2011 at 9:25 pm

    I was in Vietnam 1971-1972.Jan 11,2011 the retina in my left eye detached.In June I was diagnosed with multiple myeloma,non hodgkins lymphoma, and stage 2 leukemia. I am now having problems with my right eye.Could the retina detachment be caused by my exposure to agent orange?

    • Randall V. Wong, M.D. December 6, 2011 at 9:02 am

      Dear Dan,

      I am not aware that AO ever caused retinal detachment. Given your diagnosis (I am sorry to hear this), I’d be more concerned that any of the blood problems might be secondarily affecting the retina.

      r

  • Beth December 6, 2011 at 7:16 pm

    I am a 31 year old female who recently was diagnosed with neovascular glaucoma. I have lost all vision in my left eye and recently underwent an Ahmed tube shunt surgery to hopefully relieve my IOP and horrible headache. Before that procedure, I underwent panretinal photocoagulation to “zap the vessels”. My greatest fear is that this condition will affect my good (right) eye. Is there a great chance that this will develop in my other eye? This all started when I was originally diagnosed many months back with a retinal vein occlusion. Through testing it was determined that I have a genetic condition which makes me highly susceptible to blood clots, which is was caused my retinal occlusion according to the doctors.
    Any information you can provide is greatly appreciated. Thank you for your time.

    • Randall V. Wong, M.D. December 12, 2011 at 10:59 am

      Dear Beth,

      As long as the right eye remains healthy, the neovascular glaucoma won’t develop. The neovascular glaucoma developed as a result of the vascular occlusion. Assuming you can remedy the clotting disorder, you probably won’t occlude in the right eye.

      Randy

  • Sandy Brammer September 26, 2012 at 2:02 pm

    I have read that radiation may contribute to retinol neovascularization. Can you point me to any research on this as I am involved with X-ray studies on a regular basis.

    • Randall V. Wong, M.D. October 2, 2012 at 1:23 pm

      Dear Sandy,

      Not aware of such. I know there is a study using radiation to treat wet ARMD.

      Look up “brachytherapy for ARMD.”

      r

  • skip schaefer September 30, 2012 at 1:19 pm

    Dr. ls there a correlation between detached retina and digoxin?

  • Brian December 21, 2013 at 12:31 am

    Hi,
    I was diagnosed with 2 branch retinal artery occlusions about 2 months apart in early 2013. That summer I had 2 laser surgeries to stop bleeding. Now, the Dr says the neovascularization is becoming a problem and he says surgery may be on order. We have not talked about other treatments. Should I be asking about injections? Was the laser a good idea?
    Thank you!

  • Elizabeth Kelly September 26, 2018 at 10:53 pm

    I was diagnosed with central retina vein occlusion and neurovascularization of the right eye in June 2018. I had two subsequent weekly vegf injections at Wills Eye Hospital. Then, on July 17th, I had laser surgery for neurovascularization, and on July 23, I had a Amhed tube shunt surgery for the right eye. I have had 8 subsequent weekly follow up visits. It is now September 26th. The tube shunt is working well, and my pressure in my right eye is 16. It was 30 before the tube shunt surgery. I have no signs of any neurovascularization. I credit and thank the doctors at Wills Eye Hospital, and in particularly Dr. Mantravadi. I am seeing very good now in both my left and right eye.

    • Randall Wong, M.D. October 7, 2018 at 2:59 pm

      Such a nice testament! Sound like you were/are in great, great hands. Randy

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