Difference between Age Related Macular Degeneration and Myopic Degeneration

[gfm3267l]

Is there any real difference between Age Related Macular Degeneration and Myopic Degeneration?

[flossy93]

My understanding is that Wet AMD and Degenerative Myopia are eye diseases caused by two different processes, but that they share a common symptom (the abnormal blood vessel growth or CNV).  

Wet AMD can occur in any shape/size eye and with any prescription level.  Degenerative myopia typically occurs in patients with nearsightedness greater than -6.0 to -8.0 and an axial length measurement in the eye (front to rear size of eye) greater than 26 millimeters.

In Degenerative Myopia, the eyeball grows/stretches to be too long, and the thinning of the retinal layers and the frequent staphylomae (discreet areas of bulging at the rear of the retina) cause physical degradation that is different from wet AMD.  Both are different from Dry AMD, which is caused by an accumulation of 'drusen' on the retina and does not have bleeding as a symptom.

The bleeding from abnormal blood vessel formation (CNV) is common to both DM and Wet AMD.  In the case of degenerative myopia this is caused by breaks in the layer of tissue separating the blood-supply layer of the retina from the innermost layer that supplies the visual information.  In wet AMD I think there is a thickening of the lower retinal layers which impedes bloodflow to the inner retina; the eye responds by growing new blood vessels which can break/bleed and cause the wet AMD symptoms.

There are other symptoms of degenerative myopia not found in wet AMD, such as lacquer cracks and localized areas of thinning/breakdown of the retinal cells, resulting in retinal detachment, abnormal 'traction' on the retinal surface and macular 'holes.' - These are all caused by the tissues being stretched too thin by the elongation of the eye that is typical of a very high myope who develops degenerative myopia.  

I have Degenerative Myopia so I know more about that than wet AMD, although since some of the treatments are the same I have read about both.  I hope this is helpful.

I hope this is helpful information.

[ValveJob]

I have myopic degeneration, and in January 2012, I had a CNV in my left eye.  I agree that when there is a CNV, it seems to be milder than for people with AMD.  It took only two injections of Avastin to control it whereas people with AMD usually have to keep going back month after month for an injection.

That being said, there is still the "dry" degeneration which is caused by a thinning retina in myopic degeneration and by biochemical changes (which I don't understand) in AMD.

[Ray T Oyakawa, MD]

In my experience choridal neovascularization in myopic degeneration seems to be milder.

Dr. O.