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.

IOL centration and placement

A perfectly placed IOL is centered and right side up in the capsular bag. Perfect placement of the IOL relies on controlling the preceding steps of the cataract surgery. The first step of IOL placement immediately follows the removal of all the lens material. The capsular bag is reformed with an ophthalmic viscoelastic device (OVD) or viscoelastic. I typically use a cohesive OVD to fill the capsular bag. I am careful to inject a wave of OVD ahead of the cannula to protect the posterior capsule from the relatively sharp cannula. I try to fill the capsular bag without releasing OVD anterior to the anterior capsule into the sulcus, as this can compresses the bag and makes IOL placement more difficult.

Sometimes the wound must be extended to allow IOL placement. With typical coaxial phacoemulsification the needle requires an incision from 2.5-3.0 mm. Depending on the type of IOL and the insertion technique you may need to extend the wound to as much as 4.0 mm for a foldable IOL and 6.0 mm for a PMMA IOL. Extension of the wound is typically done with the keratome or a crescent blade. It is better to make a well formed and controlled extension of the wound than stretch the wound during lens placement. Stretched wounds often leak and require sutures or increase the risk of infection. Many of the newer IOL insertion systems do not require enlargement of the wound beynd that required of the phacoemulsification needle.

Placing a PMMA IOL is simple, as no folding is required, but does require a larger wound that can extend rehabilitation time and induce astigmatism. The wound is extended to 6.0 mm for a typical PMMA IOL with an optic size of 6.0 mm. Kelman-McPherson (or similar) forceps are used to grasp the trailing haptic and adjacent ½ of the optic. Hold the forceps on their side to keep the IOL flat while placing the leading haptic through the wound and down into the capsular bag. The forceps are released and repositioned onto the trailing haptic which is then placed into the capsular bag. A Kuglen hook (or similar instrument) may be used to place the trailing haptic.

Foldable IOLs may be placed with forceps rather than with an injector especially when using a three piece IOL design. Forceps placement requires a larger incision than is needed when using an IOL injector but is a very controlled process. As IOLs get thicker with increasing dioptric power, the incision may need to be slightly larger with high power IOLs (4.0 vs. 3.5 mm). There are 2 basic folding strategies using forceps. The first strategy involves folding the IOL axially along the axis of the haptics and the second strategy shifts the fold 90 degrees so that the haptics fold onto each other which looks something like a “moustache” (see video). An IOL with an axial fold is easier to insert, allowing for a smaller incision, but requires a 2 step procedure to place both haptics in the bag. An IOL with a moustache fold is harder to insert, requires a larger incision, but as the IOL unfolds both haptics slip into the bag in one step.

The most common technique to insert a foldable IOL is through an injector. These systems use a plunger to squeeze an IOL through a cartridge into the eye. The single piece acrylic and silicone plate haptic IOLs are the simplest to use with injectors. These designs have haptics that are sturdy and resistant to damage from the plunger as it forcefully pushes the IOL through the cartridge. The three piece IOLs are more difficult to inject as the haptics are more fragile and susceptible to plunger damage. The cartridge tip of the injector system can damage Descemet’s membrane. Surgeons should ensure that the tip is under Descement’s by placing the “toe down” as the cartridge passes through the posterior cornea.

When placing the IOL surgeons need to be sure that the IOL is right side up. All common IOLs (except plate haptic) are made with the haptics in the same configuration. IOLs are designed to rotate in only one direction safely – clockwise. The haptics are designed so that a right handed surgeon can most easily rotate the IOL into position using a hook at the junction of the optic and haptic. If the IOL is upside down the haptics will create an “S”, reminding you to Stop and flip the IOL. When a 3 piece IOL is left upside down it can cause a significant myopic shift. This is because the haptics in 3 piece IOLs are often angulated to push the optic posteriorly and support the vitreous face. When the IOL is upside down, the haptics push the optic into a more anterior position which creates a myopic shift.

IOL designed for rotation by right handed surgeon

When upside down the IOL looks like an “S” so Stop

While placing the IOL surgeons should confirm that both haptics are in the capsular bag. When one haptic is in the bag and one in the sulcus the IOL will not center. As the diameter of the capsular bag is more constrained than the sulcus, the optic of the misplaced IOL will decenter toward the sulcus placed haptic. This can be remedied by adding OVD and rotating the IOL clockwise while pushing posteriorly with a hook at the junction of the optic and IOL.

If the IOL still does not center despite having both haptics in the bag there are 2 most likely possibilities: haptic damage requiring IOL removal and zonular dialysis. IOL decentration from small amounts of zonular dialysis can often be overcome by rotating the IOL. Rotation of the IOL is especially effective with three-piece IOLs. Aligning the the three-piece haptics to the axis of weakness supports the zonules and often centers the IOL. If rotation does not work adding a capsular tension ring may center the IOL.

When the capsular bag is not perfect IOL placement is more difficult. A single anterior capsular tear that has not gone radial is a common problem that usually causes no long term problems. Some surgeons will make a controlled radial incision 180 degrees away and place an IOL in the bag. Another option is to place a single piece acrylic in the bag as this IOL places little tension on the bag which makes extension of the radial tear less likely (figure 7). The final option for an anterior capsular tear is to place a three-piece IOL in the sulcus. The foldable single piece IOLs (both the acrylic and plate haptic) are not a good choice for the sulcus as their haptics can cause pigment disruption of the iris and inflammation and their smaller size allows lens dislocation.

If the posterior capsule is not intact the IOL is usually placed in the sulcus. The wound can be extended to allow placement of a large PMMA IOL into the sulcus but more commonly a foldable IOL is placed into the sulcus using either forceps or an injector. If the posterior capsular tear is round or has been rounded by creating a continuous posterior capsulotomy, the IOL can be gently placed into the bag.

If the capsule is not adequate for IOL support the surgeon has several options, none of which is clearly superior. An anterior chamber IOL can be placed if the angle is healthy, although this requires extension of the wound to 6 mm. The IOL can be sutured to the iris with 10-O Prolene suture using a foldable IOL. Another option is to suture the IOL to the sclera using either a foldable IOL, or extending the wound to for a large PMMA IOL with eyelets on the haptics designed for suturing to the sclera.

References:

Thomas A. Oetting, MD, Cataract Surgery for Greenhorns, MedRounds Publishing, 2005, (available at http://www.medrounds.org/cataract-surgery-greenhorns)

Oetting, TA, Beaver HA, Johnson AT, Intraocular Lens Design Material and Delivery, in Essentials of Cataract Surgery, Henderson, Slack, Thorofare NJ, chapter 17, pages 133-146.

Chang, DF, TA Oetting, T Kim, Curbside Consultation in Cataract Surgery, Slack, Thorofare NJ, 2007.

staining the vitreous with kenalog

One of the trickiest parts of an anterior vitrectomy is seeing the vitreous.

You can often see the nearly invisible vitreous strands pushing another structure aside or detect that the vitreous has occluded an I/A aspiration port. However directly seeing the vitreous is difficult. Scott Burk at Cincinatti Eye helped to solve this problem with his description of using Kenalog (off label) to stain vitreous that had prolapsed into the anterior chamber (ref below). As Kenalog is not approved by the FDA for this indication and as some retinal surgeons have had sterile and even infectious endophthalmitis from using Kenalog its use is controversial. However it is a very useful adjunct to anterior vitrectomy. For more detail on vitrectomy pls see: http://www.medrounds.org/cataract-surgery-greenhorns/2005/10/chapter-5-managing-surgical.html or the section in this blog.

Dr Burk described a process to wash the preservative off of the Kenalog to use in the anterior chamber. His process dilutes the 40mg/ml Kenalog 10:1 and washes off the preservative with a filter. I have summarizied the steps of his technique below and show the technique in the video. Please keep in mind that this is not approved by the FDA for this technique and does carry some risk of TASS (sterile anterior chamber inflamation) and of endophthalmitis.   you can also use the preservative free kenalog which is now available and dilute it 10:1 which although more expensive is easier and is approved for intraocular use.

Preparing the Kenalog Stain

• TB syringe to withdrawn 0.2 ml of well shaken Kenalog (40mg/ml)
• Remove the needle and replace with a 5 (or 22) micron syringe filter (Sherwood Medical)
• Force the suspension through the filter and discard the preservative filled vehicle
• The Kenalog will be trapped on the syringe side of the filter
• Transfer the filter to a 5 ml syringe filled with balanced salt solution (BSS)
• Gently force the BSS through the filter to further rinse out preservative
• Repeat rinsing a few times
• Place a 22 gauge needle on the distal end of the filter
• Draw 2 ml of BSS into the syringe through the filter to resuspend the Kenalog
• The Kenalog (now without preservative and dilute 10:1) will stain vitreous strands white

one of the nice things about the kenalog stain is that you can better understand the fluid dynamics of vitreous removal.  you can see the vitreous streaming around the cutter with a leaking wound.  you can see the vitreous heading better toward the cutter if you hold the cutter low and the irrigation cannula high.  here is a video showing these principles. 

References

Burk SE, Da Mata AP, Snyder ME, Schneider S, Osher RH, Cionni RJ. Visualizing vitreous using Kenalog suspension J Cataract Refract Surg. 2003 Apr;29(4):645-51

Burk, SE, Question 32: When and How Do I Stain the Vitreous With Intracameral Kenalog? from Chang DF, Oetting TA, Kim T, Curbside Consultations in Anterior Segment Surgery, Slack Inc, Thorofare NJ, 2007.

learning phaco chop

         Photo credit Jeff Gentner  /  AP

Shirley and Stan White's son, Andrew White, died in his sleep on Feb. 12, 2008, while taking a Seroquel, a powerful antipsychotic prescribed as a sleep aid. Shirley White holds a box of her son's prescription medication is photo taken in the their son's bedroom in Cross Lanes, W. Va.

Antipsychotic Prescribed as Sleeping Pill by Matthew Herper, Forbes September 2004

"When AstraZeneca introduced the schizophrenia drug Seroquel in 1997, it was a dud. The London-based drug giant had no experience selling psychiatric drugs, and its then small sales force couldn't compete with the might of Eli Lilly and Johnson & Johnson, which ruled the market for antipsychotic medicines."

AND

"Henry Nasrallah, a psychiatrist who is the associate dean of the University of Cincinnati School of Medicine, says he has prescribed Seroquel as a sleep aid for patients who also suffer from other mental disorders. "A lot of our patients beg us for sleep," says Nasrallah. "And if we are going to give them something for sleep, we want to give them a mild, not harmful, drug that seems to help both their sleep and their depression or anxiety."

---

Since the writing of Herper's 2004 article, Seroquel grew into a blockbuster antipsychotic that continues to be prescribed off-label for insomnia. The drug is connected to veterans dying in their sleep. Often prescribed to vets for insomnia and PTSD, the antipsychotic gained momentum the last 7 years, with increased sales and prescriptions.

The doctor quoted in the 2004 article above, psychiatrist Henry Nasrallah, is a doctor whose hand is heavily in the pharmaceutical paid speaker cookie jar. Nasrallah receives income from AstraZeneca, Pfizer and Johnson and Johnson, which could be a conflict of interest, when speaking about Benedryl vs. Seroquel as he did back in 2004.

It's incredible this story can be written again today, 7 years later. Since then AstraZeneca was fined $520 million dollars for illegal marketing of Seroquel, entered a CIA (Corporate Integrity Agreement) with the Dept of Justice, and internal documents have been exposed detailing AstraZeneca insiders as knowing the antipsychotic had metabolic possibilities, with weight gain and diabetes.

Seroquel lawsuits totalled 26,000 and some remain to be heard in court while others have an unsettled case, where the plaintiffs are waiting for actual settlement numbers, and even information packets. Bloomberg reported cases settled in August 2010 and those plaintiffs have yet to see a dime of settlement money, though the general consensus is about $10,000 per person, for a lifetime body damage of diabetes.

The drug is in multiple trials in the XR version for a multitude of indications.

There are some people who tout atypicals as wonder drugs, and some might say they "work". For those who say that, I say listen to those who this drug in particular has injured. Those are the ones paving the way to AstraZeneca's Golden Wonder Drug blockbuster bank account, the drug that has become the multi-purpose antipsychotic and the one with dangerous side effects....yet where are the funtioning Schizophrenics or patients who suffer with psychosis? what are they saying about this drug's usefulness?

When does America stop tolerating paid pharma doctors and researchers? What will the next 7 years bring? how many more lawsuits or deaths?

consent for cataract surgery

The consent is of course the most important part of the pre-operative visit -- especially if things go wrong later.   consents can be tricky as different patients want different levels of detail.   the consent

for cataract surgery has also gotten a bit trickier as toric and presbyopic IOLs have entered our practice.   here i'm going to briefly focus on the essentials for consenting patients for cataract surgery.

5 essential parts of a consent

• identify yourself and your role in the surgery
• describe the two options – cataract surgery or hold off on cataract surgery
• describe the procedure briefly
• describe potential risks – 1/100 chance vision will be worse after surgery
• describe potential benefit – 9/10 chance vision will be normal with glasses following surgery

Talk your patient through the procedure briefly

• we replace your cloudy natural lens with a clear artificial lens
• use the words: injection(w/RB), cut, and possible stitches in your discussion
• no we don’t use the laser (much confusion about Yag for secondary cataract)
• we may patch your eye overnight following the surgery
• we will prescribe new glasses when the eye is stable – 2-4 weeks post op 

Benefits:

• 95 % better than 20/40 
• 96 % better vision than pre-op
• I lower these percents with increasing retinal or optic nerve disease

Risks:

• 1% vision worse than pre-op
• death (<1:100>
• loss of eye (<1:10>
• irregular pupil (1:100)
• after cataract (1:20 requiring laser in 2 years with sa60/ma60)

Document

• Functional visual disability, give examples
• Complete consent form legibly
• In pts chart write something like: 

“I discussed the risks and benefits of cataract surgery with Mr. Jones and his son in terms they seemed to understand. Mr. Jones expressed to me that he understood the small but real risk of surgery, including loss of vision as outlined in the consent form, and he decided to have surgery”