Thursday, September 27, 2007

Pars Plana Vitrectomy

That's the name of this procedure. The jelly in the back chamber of the eye is called the vitreous, and in some circumstances, like bleeding into the vitreous from diabetes, you want to take the vitreous out -- "vitrectomy" it. Right adjacent to the cornea, on the white part of the eye (the sclera) there is an area that is a few millimeters wide that doesn't have any retina behind it. This area is called the pars plana. It's a perfect place to insert instruments. If you insert an instrument further back, where the retina begins, you put a hole through the retina and cause a detachment. Not good. So, this is a pars plana vitrecomy.

The tube on the left is connected to an elevated bag of fluid that keeps the eye inflated so it doesn't collapse like a squished grape when you make your other incisions. Those two metal things on either side of the cornea and short hollow tubes that go through the pars plana into the vitreous chamber. We use these two tubes to place instruments through. Usually one hand has a fiberoptic light so you can see what you're doing in there. The other hand has an instrument, like a cutter, or a pick or a laser, or whatever you need at the moment.

It used to be that you would make an incision and just push the instruments in and out of the eye through the cuts. With this new "hollow tube" technique, you just stab the tubes in, do the surgery and then take them out at the end. You don't even need to put any stitches in. It's very cool surgery.

The little lens suspended above the cornea is actually attached to a huge operating microscope. The microscope usually focuses light onto the cornea, but this lens allows you to focus it further back into the vitreous.

Oh, and the big metal thing is a lid speculum. When I operate, people often tell me they're afraid they'll close their eyes. Not to worry. We just pry them open with metal instruments.

One more subtle, but important detail. In the lower right corner of the photo, above the eyebrow, next to the blue drape, there is a purple arrow. That arrow says "operate on this eye." It's bad form to operate on the wrong eye. Especially if you're doing an enucleation. (Look that one up. It gives me the shivers just thinking about it.)

I do have to say that I love my job!


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Boni said...

I'm glad I had my lunch before I read that. I'm surprised I kept it after looking up enucleation images. Thanks Doc. Very eye opening. Yah.

Tamara said...

Oh God! I just ate lunch..eww! eww! eww! Props to you Doctor for being able to look at that on a daily basis..

LOL @ Boni!

Marianas Eye said...

Eyes never made me queasy. The only times I passed out was delivering babies... all that screaming.

Mark said...

Hey Doc,
I've had three of these so far and I am having a fourth on my other eye this week. I have to say you have described and illustrated this for me superbly. I really appreciate this. You have taken alot of the "scare" out of this procedure for me. Great work - and sincerely, Thank You!