American Academy of Ophthalmology Web Site: www.aao.org
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January 2006

 
News in Review
A Look at Today’s Ideas and Trends
By Linda Roach, Contributing Writer
Edited by Brian A. Francis, MD
 
 

Reports of intraoperative floppy iris syndrome (IFIS) continue, but cataract surgeons have learned more about the nuances of this medication-induced surgical problem, according to one of the ophthalmologists who first recognized IFIS.

"Cataract surgeons are all acquiring more experience with this syndrome, and so we're better versed in how to deal with it," said David F. Chang, MD, of Los Altos, Calif.

Dr. Chang, along with John R. Campbell, MD, linked the drug Flomax (tamsulosin) to IFIS last year. Flomax is an alpha1a receptor blocker prescribed to treat the symptoms of benign prostatic hyperplasia.

"We've found that there is a continuum of severity of this syndrome. It's not like everyone taking Flomax has pupils that behave exactly the same way," said Dr. Chang, clinical professor of ophthalmology at the University of California, San Francisco. "I've seen just about every level of severity, from mild billowing without prolapse to the full-blown syndrome with iris prolapse and sudden constriction.

"In my experience, the best predictor is the degree of preoperative dilation. A
well-dilated pupil indicates a relatively healthy iris dilator muscle and portends a milder degree of IFIS," said Dr. Chang. "In contrast, a small pupil indicates poor dilator muscle function and predicts severe IFIS."

During the Spotlight on Cataract Surgery symposium at the Academy's Annual Meeting in Chicago, an electronic audience response poll indicated that only 20 percent of respondents had never seen a case of IFIS.

When audience members were asked to indicate their preferred method for managing IFIS, the responses were: iris hooks (46 percent), Healon 5 viscoelastic (35 percent), pupil expansion rings (5 percent) and other methods (14 percent).

Based upon reports that he has received, Dr. Chang noted that IFIS can still occur up to five years after a patient has stopped taking Flomax. IFIS has also been associated with the use of nonspecific alpha1 antagonists, such as Hytrin (terazosin), Cardura (doxazosin) and Uroxatral (alfuzosin), Dr. Chang said. 
 
"These drugs are less commonly prescribed, and the IFIS does not seem to be as prevalent or severe as with Flomax," Dr. Chang said.

Last October, the FDA added a warning about IFIS to the prescribing information for Flomax. But Dr. Chang wonders if time will show the warning to be appropriate for these other alpha blockers, too.

There is strong evidence that the rate of posterior capsular rupture with unrecognized IFIS has historically been very high, according to Dr. Chang. "It is therefore mandatory to ask about a history of alpha1 blocker use in anyone who dilates poorly so that alternative small pupil strategies can be employed," he said. Of the most popular methods for coping with IFIS, Dr. Chang had the following  advice:

  • Partial thickness sphincterotomies and mechanical pupil stretching will not work, and some feel that this worsens the IFIS condition.
  • Preoperative atropine and the technique of bimanual microincisional phaco are beneficial but work best with milder IFIS cases.
  • Healon 5 viscoelastic works well with IFIS of mild to moderate severity.
  • Iris retractors and pupil expansion rings provide the safest surgical visibility with the most severe IFIS cases.

Dr. Chang reiterated that the preoperative dilated pupil diameter helps to predict whether the IFIS will be mild, moderate or severe.

Because many surgeons lack experience with Healon 5, Dr. Chang feels that the single most reliable approach is probably iris retractors. "These are easy to insert and remove, do not require special injectors, are reusable (depending upon the manufacturer), and will allow surgeons to use their standard phaco settings and technique with even the floppiest of irides," he said.

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Dr. Chang is a consultant for AMO but has no financial interest in any products mentioned.




Pediatrics

Pregnant Mom's Drinking May Affect Infant's Vision

A child doesn't need to have outright fetal alcohol syndrome (FAS), and the mother does not have to be an alcoholic, for maternal alcohol use during pregnancy to reduce visual acuity in the infant, a study conducted in Cape Town, South Africa, by American researchers has concluded.

Furthermore, the visual acuity deficit was most significant in children of mothers who were 30 or older at the time of delivery.

"Many women who drink during pregnancy, even if they are not alcoholic, tend to concentrate their drinking on the weekends," said co-author Sandra W. Jacobson, PhD, professor of psychiatry and behavioral neurosciences at Wayne State University, in Detroit.

"If they're drinking four or more drinks at a time, their child is particularly at risk for these and other alcohol-related neurobehavioral problems," Dr. Jacobson said.

In a prospective study published in The Journal of Pediatrics,¹ the researchers reported on 61 women who drank heavily during pregnancy, and 70 who drank little or no alcohol.

The babies were tested at 6.5 months of age using the Teller Acuity Card (TAC) test of resolution acuity. Normal acuity on TAC is 6.8 cycles per degree in infants this age, and the fifth percentile is < 3.38 cycles per degree.

Of the infants examined, 22 were diagnosed with FAS, and scored a mean of 2.69 cycles per degree. Whereas 27 percent of the infants with FAS scored below the fifth percentile, 9 percent of the infants without FAS scored that low. However, half of these low-scoring infants were born to mothers who reported drinking more than five drinks per occasion during pregnancy.

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1 Carter, R. C. et al. J Pediatr 2005;147:473"??‚??“479.




Patient Education

Know About Medicare Part D

Medicare Part D "the prescription drug benefit"debuts this month, complete with a wealth of resources to help sort out the confusing program for physicians and patients alike. Wading through this sea of information, it's easy to see why so much is out there.

Overall, the cost of coverage is a national average of $32.20 a month, but this varies widely from state to state, and even within states. In Florida, for instance, a patient can pay as little as $10.35 or as much as $104.89, according to figures from CMS, compiled by the Kaiser Family Foundation, a health care information and advocacy institution. In other states, the premium is as low as $1.87.

Below are some Web sites with downloadable information sheets, which can be printed to help office staff and patients. Not interested? A November survey by Kaiser found that 76 percent of Medicare beneficiaries have never used the Internet, 61 percent don't understand the drug plan and 32 percent expect to get the information they need from their physician.

Resources for Physicians

Academy's link to information: www.aao.org/patient_ed/medicare_benefit.cfm

Medicare Toolkit:  http://www.cms.hhs.gov/MLNProducts/downloads/provtoolkit.pdf

State-by-state fact sheet, comparing prices:  kff.org/medicare/7426.cfm


Resources for Web-Savvy Patients

"Your Pharmacy Benefit: Make it Work for You!"
http://www.pueblo.gsa.gov/cic_text/health/pharmben/workforu.htm
Or order a copy by calling 1-888-878-3256 on weekdays.

"Things to Think About When You Compare Plans"
http://www.medicare.gov/publications/pubs/pdf/11163.pdf

State-by-state fact sheet, comparing prices:
 http://kff.org/medicare/7426.cfm

Web site by a coalition of physician and consumer groups:
http://www.yourpharmacybenefit.org/

Answers to 76 questions about Part D:
http://www.medicarerights.org/maincontentrx76questions.html

Low-income help for Part D recipients:
www.kff.org/medicare/7327.cfm

Telephone assistance for patients: 1-800-MEDICARE (1-800-633-4227)

 

Eye on Agriculture:
Retinal Scans Nothing to Moo At

Retinal scanner to track cattle
Caption: Bossy the cow won't be incognito when she gets into a large herd anymore, if engineers at New Mexico State University have their way.They are testing a cylindrical, portable retinal scanner as a way to identify and track cattle. The engineers' work is part of an effort by the USDA to establish a National Animal Identification System.




In Iraq

Low Endophthalmitis Rates Among Injured U.S. Soldiers

Physicians caring for wounded American troops in Iraq have found that the risk of endophthalmitis from leaving intraocular foreign bodies in place for days or weeks isn't as high as might have been expected. "These guys are in a dirty, dusty environment, out in the middle of the desert, and their eye injuries don't see the level of care as quickly as they would in the United States," said Allen B. Thach, MD, a colonel in the Army Reserve who spent three months in Iraq during the current conflict.

Dr. Thach and an American military team that has examined traumatic eye injuries around the world reached their conclusion after doing a retrospective examination of 55 troops in Iraq with penetrating eye injuries, usually from explosions. The seven ophthalmologists reported their findings in Ophthalmology

Their retrospective case series found no endophthalmitis despite a mean of 20.6 days (range 0 to 90) before intraocular foreign body removal. Loss of visual acuity in the patients appeared to occur for reasons other than intraocular infection, the researchers found.

"Even when medics are doing triage for other very severe injuries, they're also doing the right thing for the eye to try to protect it from further injury."

Dr. Thach and his colleagues identified three probable reasons for the dearth of endophthalmitis even though the foreign bodies stayed in place:

  • Early protection of the injured eye by medics.
  • Closure of the wounds shortly afterward by specially trained ophthalmologists in the field.
  • Prompt use of antibiotics to care for the troops' other, more serious injuries.

In addition to stabilizing patients with life-threatening injuries, the medics cover the eyes with shields for protection. Then an ophthalmologist at a fully equipped field hospital or a mobile operating tent performs globe closure. The foreign bodies are left in place in almost all cases, and topical antibiotics might be prescribed in addition to the systemics being delivered for other injuries, the study reports.

The wounded then are evacuated to an interim stop in Germany, where another ophthalmic exam (and in a few cases ophthalmic surgery) occurs. Definitive treatment usually is delayed until arrival at a military hospital in the United States.

In the 38 eyes in which the timing of removal was available, 48 percent achieved final vision of 20/40 or better, and 32 percent had visual acuity of 20/200 or worse. Another 9 percent required enucleation because of the severity of injury. These results compare to 47.5 percent to 71 percent of patients with final acuity of 20/40 or better in noncombat-related foreign body injuries. However, direct comparison is difficult because follow-up in the military cases varied, from 22 to 330 days after injury (mean, 119.1 days).

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1 Ophthalmology 2005;112(10): 1829' 1833.