Showing posts with label intraocular lens. Show all posts
Showing posts with label intraocular lens. Show all posts

Dec 14, 2015

Freeing and Removing an IOL

removing an IOL can be tricky.  first you have to free the IOL from its capsular adhesions.  then you have to get it out.  here i will share a few tips on removing IOLs.

freeing the IOL from the capsule.  The ease of IOL removal is mostly dependant on how long the IOL has been in the bag.  IOLs which have been in the bag for a few weeks are very easy to free from the bag.  IOLs that have been in the bag for years can be very hard to remove.  Removing an IOL with an intact posterior capsule is far easier than when the patient has had a YAG capsulotomy. 

the first step is to somehow get a visco dissection plane started between the IOL and the capsule.  I like to use dispersive OVD especially when the posterior capsule is not intact.  with IOLs that have been in place for a while i like to use a 27 gauge needle attached to viscoat and use the sharp end to get under the capsule and then inject the viscoat. then i will sometimes use the Duet micro forceps (as shown in the video) to lift the capsule to get a canula under for more viscodissection.  I also like to use a flat hydrodissction cannula for visco dissection as the flat surface makes it easier to get between the capsule and the IOL.  most of your attention should be directed to freeing up the haptics with viscodissection.  If the posterior capsule is intact the viscoat will often track around the optic and free it from it posterior attachments. after the capsular adhesions are freed try to spin the IOL clockwise to allow the haptics to spin free.  sometimes the haptics are just too stuck and must be cut to free separately or are even left in the bag.




removing the IOL can be done through a small incision (refolding or cutting) or by extending the incision to the size of the optic.

The high index of refraction acrylic IOLs (eg. MA60, SA 60) can be refolded within the eye either using the folding forceps or the henderson technique.   The standard refolding technique uses a paracentesis across from the main wound (3.5 mm) to introduce a spatula to place under the optic while using an open IOL insertion forcep above the optic in the anterior chamber.  while lifting with the spatula and coming down on top of the optic with the open insertion forceps the IOL can be folded inthe anterior capsule.  once folded  the optic is simply removed through a 3.5 mm or so wound   please use lots of OVD during this process.  refolding the IOL only works well with thin acrylic IOLs likem the SNWF, SA60, MA60 and in my hands is virtually impossible with thick acrylic IOLs like the AR40 and the slippery IOLs like the silcon three piece IOLs.   see video of refolding




The henderson (bonnie henderson boston ma) technique for folding soft IOLs such as the IQ single piece acrylic is very slick.   dr henderson's technique is to simply pull on an externalized haptic (with 0.12 or similar toothed forcep) while pushing on the optic 180 degrees across from the wound (inside the eye) with a hook (eg. Kuglen) amazingly the IOL folds itself and pops out of the eye.   see video



There a few ways to cut an IOL to get the optic small enough to remove through a small incision.   One classic technique is to only cut about 2/3 through the IOL and make what looks like a Pac Man and rotate the IOL out through the wound as shown in the video.


You can also cut the IOL completely in half or into thirds and bring out the pieces.  i like to use the Osher mildly serrated cutter from Duckworth and Kent as shown in this video.  you can usually keep the IOL from flopping around too much by holding the externalized haptic with this cutter.    if you are in a bind you can even use Vanna scissors to cut the IOL.



i also think the Duet forceps and IOL cutters can be handy to cut IOLs and haptics.  you can use the Duet forceps through a paracedntesis to stop the IOL from flopping about and hitting the cornea.  both the cutter and the forceps can pass through a paracentesis.  here the Duet system forcep is used to hold an IOL while cutting in the video.

Dec 12, 2015

secondary anterior chamber AC IOL

Anterior Chamber (AC) IOL are a great option for the rehabilitation of aphakia in patients intolerant of their contact lenses. You need to be ready to do place an AC IOL in case your case gets complicated and you loose capsular support to place the IOL behind the iris. Your OR should always have stocked AC IOLs ready to go incase they are needed when things go south.

this is the best article comparing IOL selection with loss of capsular support:
Wagoner MD, Cox TA, Ariyasu RG, Jacobs DS, Karp CL, Intraocular lens implantation in the absence of capsular support: a report by the American Academy of Ophthalmology. Ophthalmology. 2003 Apr;110(4):840-59

In the following video i show a recent case where i placed an AC IOL in a patient with a history of congenital cataract who is aphakic and intolerant to her contact lenses. we considered her options and decided to place an AC IOL as she had no history of glaucoma, had a normal angle, and was so young. we placed miochol to bring down the pupil, used Viscoat in case some of the OVD was retained in the vitreous, placed a peripheral iridotomy with the anterior vitrectomy handpiece, and closed the 6 mm scleral tunnel with 2 10-O nylon sutures.




Please always remember to place a peripheral iridotomy. i think this is best done with the anterior vitrector as shown in the video. I would like to show you pictures from a patient who came to me for a second opinion following complex cataract surgery about a year ago. during her surgery the functional support of the capsule was lost and the surgeon placed an AC IOL. the patient was bothered by a chronic head and brow ache and had elevated intraocular pressure. here is what she looked like that day:




You can see she has iris bombe and no patent peripheral iridotomy is visible. i took her to the laser and performed a Yag peripheral iridotomy. I chose a spot near the haptic at about 10 oclock as this region of the iris was posterior and safely away from the cornea. immediately following her Yag PI the iris bombe resolved and she was more comfortable. here is a picture from just a few days later showing the IOL and iris in good position.