blah
Really, really really blahty
Posted at 12:26 #

"Optimal timing of capsular tension ring implantation"
[www.ncbi.nlm.nih.gov...] -- Experiments on cadavers regarding placement of a reinforcing ring.
Posted at 07:42 #

Capsular Tension Rings (introduction in USA in 2003?)
[www.eyeworld.org...] -- Howard Fine describes using the capsular tension ring, for any patients with weakened zonules.

As far as I can figure, this is apparently a good piece of kit for relieving the tension on the zonules during cataract surgery, but does not necessarily seem to address I. Maumenees postoperative concerns with Marfans concerning the advantages of a single suture for keeping the lens capsule centered postoperatively.

I also asked her to comment on 'Cionni rings'. If I understood correctly, she seemed to think that they were a rather complicated alternative to simply suturing a lens to the sclera.
Posted at 06:12 #

General concerns with Marfan's patients regarding cataracts
[www.marfan.org...] -- From my 15 Jan conversation with Dr. Irene Maumenee JH:

• Almost all folks with Marfan's develop cataracts by age 50.
• Traditional cataract surgery involves making an incision in the lens sac (capsule), sucking out the liquid in there (which has become 'cloudy', or otherwise problematic in the case of a cataract), and placing a plastic lens in the sac.
• The "zonule" fibers that hold the lens sac in place are more brittle in folks with Marfans. It's fairly common for the lens to be slightly off-center (with respect to the pupil), and one also sees "jelly eye": When the eye moves rapidly and then stops, the lens (because it's not so tightly held) 'keeps going' and causes the iris (right in front of the lens) to shimmer or shake like jelly.
• Traditional cataract lens replacement puts quite a bit of stress on the zonules during the procedure itself. Apparently more stress during the insertion of the replacement lens then during the extraction of lens fluid.
• There's a chance that the lens sac could become detached, and if so, a slight chance of it bonking the retina and losing sight completely. Even if the operation goes well, afterwards there is also higher inertial stress if the replacement lens is heavier than the liquid replaced. She says she sees a number of marfans who are initially satisfied with the procedure, but then their sight degrades once more after the replacement lens in one's natural sac displaces with time.
• It used to be that folks put a lens in the 'anterior chamber' between the cornea and the pupil. This is a particularly bad idea for Marfan's, since that chamber is typically larger in Marfan's. The replacement lenses (made for the average population?) have a tendency to shift around and irritate the inner side of the cornea.

Cataract: recommended procedure (Maumenee)
From 15 Jan conversation with Dr. Irene Maumenee:

Her favored procedure:

1. As with traditional cataract procedures, making an incision in the lens sac, and extracting the fluid.
2. Insert a (large?) replacement lens in the 'posterior chamber' where it is held in place by the vitreous pressure pushing on the (empty) lens sac on the one side, and the iris on the other side.
3. And then putting in one suture at 12 o'clock to keep it centered.
4. I asked whether this deflated lens sac right along the path of light into the eye might not not make it hard to correct vision completely. She said one typically uses a laser to burn off the part that is right along the optical axis.

In the case of my left eye, where the lens is severely displaced, she would recommend taking it out completely (sac and all) and then suturing the replacement lens in at two locations (12 and 6 o'clock, or some prefer 9 and 3) instead of one.
Posted at 05:23 #

Left eye (extreme lens dislocation) recommendations

From 15 Jan. conversation with Dr. Irene Maumenee.

She encouraged me to try and get my left (bad) eye fixed!

I had heard that it was not worth bothering to work on my left eye, because 8 years old (when my displaced lens was discovered) is too late neurologically to develop the brain 'software' to make sense of optical info.

But she said that with Marfan's, lens displacement is rarely present at birth or during early vision development in infancy. The lens doesn't typically go off-center until, say, after the age of two or three. And so there's quite a good chance that I could get some degree of improved vision in that eye, and of course that might change the balance of how dependent I would feel on my right (good) eye.
Posted at 05:18 #

Ab Externo fixation of the Cionni modified capsular tension ring
[www.ncbi.nlm.nih.gov...] -- PubMed abstract of a J. Cataract Refract. Surg. article (2001)
Posted at 11:49 #

Managing a loose and subluxated lens
[www.ascrs.org...] -- The MCTR (Modified CTR) can be fixated to the scleral wall with polypropylene suture to achieve “in-the-bag” IOL centration and stabilization. I use this approach when feasible because this surgery can be performed through a 3.5 mm near-clear corneal incision and the capsular bag remains intact.
Posted at 10:55 #

Tips to manage weak zonules during cataract surgery
[www.eyeworld.org...] -- 1. Implant CTRs after lens extraction.
2. Injection causes less stress than manual implantation.
Posted at 10:44 #