Distorted vision and visual acuity

Hi, Can you please explain to me...I don't understand the difference between visual acuity and the quality of how I actually see.  I mean, after my retinal detachment, 3 surgeries, and regular injecitons of avastin, I am told my visual acuity is very good - 20/40!  But just because I can make out the chart, doesn't mean what I can read looks good!  I can tell you that the letter is an "E" or an "L" and so forth, but they are all wobbly, so how is that 20/40?

[Ray T Oyakawa, MD]

You probably have an epiretinal membrane causing distortion of your central vision.l  Snellen acuity as you are learning is not the best measure of visual acuity.

Dr. O.

[berrywoo]

I am sure that JodieJ's past comments and experience apply to your situation as well and strongly suggest that you read some of her posts.

I think Dr. O is correct, in saying that you probably do have some ERM. However, even under the best of ERM/ILM peeling and so forth, the distortion you are experiencing will probably never be completly  eradicated.

The Snellen chart is NOT the best indicator of real world vision. It tests vision under a pretty standardized optimal setting. There are other measures of vision that it fails to take into account. Yet, due to so many variables in vision, it is hard to measure all simultaneously with accuracy/reliability. For example in the real world there are various levels of lighting, glare, and contrast.

I definitely think that your overall vision would benefit from ERM removal. However, some surgeons will more than likely hesitate to operate due to the risks and the complex nature of your RD history and given the current level of vision (20/40), but if your really persistent then a good reputable surgeon can perform the surgery well and the distortion should be greatly minimized.

I'm sure JodieJ will comment here.... ;)

[JodieJ]

I couldn't agree with you more--your ability to read letters on an eye chart using one eye doesn't translate to your vision in the real world.  It's time for the retinal specialists to start using additional standards.

It's not clear why your vision is distorted.  Retinal detachment and the surgery to repair it can produce changes in the photoreceptor distribution, resulting in distorted vision.  (There was a post a couple of days ago from someone who was unable to read with his affected eye following RD surgery, so check past threads.)  You probably have some macular edema, which is contributing to your problems.  You may (or may not) have an epiretinal membrane (scar tissue on the macula).

I do think that your vision can be improved. (1) If you do have an epiretinal membrane, removing it surgically would probably result in significant improvement.  (You'd want this done by the very best retinal specialist around.  I'd recommend Dr. Steve Charles in Memphis if you're able to travel for surgery.)  (2) Hopefully, the Avastin injections or other treatment (and time) will reduce your macula edema.  (3) In many cases, distortions due to RD and RD surgery can be significantly reduced by means of optical corrections (glasses, contacts).  One of the patients (#2) described in the paper "Retinally Induced Aniseikonia" by Dr. Gerard de Wit was post-RD surgery, and he did benefit from specially-designed glasses.  You can download the paper free from www opticaldiagnostics com.  Unfortunately, the writing is very technical.  If you can't find an eye care provider who's willing to work with you, try emailing Dr. de Wit.  In my own case (involving botched ERM surgery), the optical correction prescribed by Dr. de Wit following online testing resulted in dramatic improvement.