What is the Macula?: Macular Diseases

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What is the Macula?: Macular Diseases

Macular Diseases May be classified by the layer of the retina they affect.The macula is the most sensitive portion of the retina.  The retina is the inside lining of the eye capturing light and sending to our brain to give us vision.  Like a sandwich, the retina has several layers.

Diseases of the macula may be classified by the layer of the retina they affect.

Symptoms of Macular Diseases

Macular diseases, such as epiretinal membranes, macular holes, macular edema and macular degeneration, affect central vision.  Symptoms can include decreased vision and/or distortion and you can’t distinguish (or at least I can’t) one disease from another based on symptoms…they are all the same.

Diseases on the Surface of tbe Macula

The more common is the macular pucker, aka epiretinal membrane (ERM).  This is a sheet of protein which forms on the surface of the retina.  Imagine the retina is the hamburger paddy.  The epiretinal membrane would be the cheese on top of the paddy.

The ERM can microscopically wrinkle the underlying macula causing changes in the vision.

Removal of the membrane with vitrectomy often remedies the situation.  The underlying retina is healthy.

Macular Diseases Involving the Retina

Often the macular tissue itself is affected.  In our sandwich analogy, the retina is the meat itself.

Anything causing macular edema affects the actual retinal tissue (meat patty) and therefore vision.  Common causes of macular edema?  Vascular occlusions (BRVO and CRVO) and diabetic retinopathy.

A macular hole develops after the retina is stretched.  There is actually an absence of tissue causing the hole. (If you took a piece of balloon, poked it with a pin and then stretched the balloon apart, you’d see the resultant pinhole…enlarged by the stretching.  Same thing happens with macular holes).

Macular edema may be treated with medicines or laser.  Macular holes are treated with surgery.

Diseases Underneath the Macula

The most common are wet and dry macular degeneration.  Macular degeneration affects the layer of cells feeding the rods and cones.  Without functioning rods and cones (the two types of cells allowing us to “see” light and color) we have no vision.

Macular degeneration principally attacks the RPE layer by permanently damaging theses cells.  This would be the lower layer of cheese underneath the patty.

There is presently no accepted treatment for dry macular degeneration.  Eye injections of anti-VEGF are one helpful treatment for the wet form.

What Does This Mean?

The macula is a small 2 mm x 2 mm area of the retina producing our useful vision.  Thus, “macular” becomes an adjective when describing various disease affecting this region.

Only the ERM involves healthy retinal tissue and, hence, the best prognosis.  The retina is the healthiest compared to the other situations.

The treatments available for most of the “macular” diseases are not necessarily successful at fully restoring vision.  When the diseases affect the tissue itself, either the retina or the layer underneath, some degree of permanence may be expected.

16 Comments

  1. Ken E says:

    Another great read. Thank Dr. Wong

  2. Melany W. says:

    Dr. Wong,
    I have been following your website for several years, ever since I developed a retinal tear from a PVD in 2010. I would very much like to know if you could put my mind to rest on a new matter while I wait to see my opthamologist.
    Yesterday I went for my annual eye exam at the optometrist & he told me everything looked fine, but I have ERM in both eyes. My vision is fine. However, I’m very upset about this being in both eyes (I had PVD in both eyes). I am going to see my retinal specialist, but could you please tell me if it is rare to have this in both eyes. This is what is bothering me the most. Any bit of “cheer” will help me immensely. And thank you so much for your informative website.

    • Melany,

      Thanks for following. This had proven to be a very powerful tool for educating, helping and building relationships.

      1. ERM following PVD/tear are very, very common. Not everyone can form an ERM, I personally believe it’s an exaggerated response to a PVD, that is, your cells on your retina tend to over produce a protein leading to the ERM (that is, not your fault!).

      2. Operate as soon as you become aware of a decrease in vision from the ERM.

      3. Find a surgeon who will be willing to operate as soon as you both agree “the earlier the better.” If your doc won’t operate early, move on. The reason? No doc should be able to guarantee improvement in vision, thus, operating early favors best resultant vision.

      r

  3. Melany W. says:

    Dr. Wong,
    Thank you so much for your response! Very appreciative of your time and efforts in answering questions.

  4. Jane says:

    Loved the cheeseburger analogy! Shared this article with some family members who have macular degeneration (dry) and they agreed it was very clear and informative. I’ve even watched some of the videos. Thanks for what you do, both here and in surgery!

  5. S.K.SHARMA says:

    Dr. Wong
    I appreciate the way u express everything about vision and the eyes. I had CNVM in my Left eye and treated with Laser which caused a permanant blank spot and my central vision is gone. Are there any chances of restoration or further treatment of CNVM I am 42 years old from India. My Right eye is perfectly all right 6/6. Any sort of precautions for the only eye

    Best regards
    S.K.Sharma

  6. Pam Hill says:

    Dr. Wong: I have recently been diagnosed with wet macular degeneration and am scheduled for first injection 11/28/12. In reviewing the information about Avastin I find “side-effects” cardiovascular in nature. I already am being treated for CAD and have a pacemaker. What is the frequency of this side effect in individuals with pre-existing cardiac disease?? I intend to have the first series of 4 injections but still apprehensive re this side-effect. Seeking some comfort, but more importantly honest input to aid in my decisions. Thanks in advance

    • Dear Pam,

      I have not had cardiac issues with any of my patients.

      I would suggest you ask your cardiologist. I am not aware that this is a problem, though initial studies with Lucentis certainly made us think about systemic effects with anti-VEGF.

      r

  7. Tom says:

    Dr. Wong. Today (July 3rd) I was diagnosed with a small Macular hole that will require surgery. I am scheduled to go on vacation to Bermuda for a week, returning July 27th. I would like to schedule the surgery when I return from the vacation. At this point, my doctor said the hole is small enough that I can wait but he wants to see me again next week to see how much it’s progressed.

    I know this is a difficult question to answer but, on average, what are the chances that a Macular hole worsens such that waiting 30 days presents more risk in repairing the hole by surgery.

  8. Tom says:

    Thanks for your quick response Dr. Wong. One thing I should’ve added is that it is a Stage 4 Macular hole.
    Does that make a difference?

  9. […] fluid develops underneath the layers of the retina.  Symptoms are most noticeable when the macula is involved, in fact, some patients may not be aware of swelling outside of the macular […]

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