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Improvingthe ViewTreatment reversesmacular degeneration

People with a relentless eye disease nowhave a better-than-average prospect ofrecovering some vision, thanks to a newdrug that takes a lesson from an anticancerstrategy, two studies show.

Age-related macular degeneration is theleading cause of blindness in the elderly. Inthe less common, wet form of the disease,rogue blood vessels escape normal growthcontrol and leak fluid into the macula, thearea at the center of the retina that enablesa person to see fine detail.

As a result of fluid disrupting their sight,people with the condition often see straightlines as crooked. This form of maculardegeneration can lead to legal blindnesswithin months.

Cancer researchers have developed a drugto stop the similarly aberrant blood vesselgrowth that’s often present in tumors. Thenew eye studies showcase a drug calledranibizumab, which is a fragment of the can-cer drug. Both drugs inhibit a protein essen-tial to blood vessel growth, says David M.Brown, a retina surgeon at Methodist Hos-pital in Houston who worked on both trials.

Preliminary studies of ranibizumab con-vinced the Food and Drug Administrationin June to approve the drug to treat wet mac-ular degeneration. The two new large trials,reported in the Oct. 5 New England Journalof Medicine, establish that ranibizumabreverses the disease in many patients.

“This is a huge breakthrough,” says Frederick Ferris, clinical director of theNational Eye Institute in Bethesda, Md.“This treatment is remarkably different fromother treatments.” He likened it to the addedpower that penicillin contributed to the fightagainst infections.

One wet macular degeneration trialenrolled 716 patients, and the other fol-lowed 423. Two-thirds of the participantsin each study were randomly assigned toreceive a monthly ranibizumab injection in

their affected eye, and one-third got an inertinjection. In the smaller study, the controlgroup also received a standard treatment—the drug verteporfin followed by laser light,which activates verteporfin. That treatmentalso combats abnormal vesselgrowth.

After 2 years, patients gettingranibizumab in the larger studycould see an average of one addi-tional line on an eye chart. Morethan one-fourth of them hadregained three lines. After 1 yearin the smaller trial, patients get-ting ranibizumab had recoveredone to two lines of visual acuity.

In contrast, patients gettingthe sham injections in both tri-als had, on average, lost acuity and could seetwo fewer lines—whether or not they gotthe verteporfin treatment.

Ranibizumab isn’t a sure cure, however.Some patients getting the drug in each trialstill showed considerable vision loss. Andeven when the drug is successful, patientsmight need to continue receiving themonthly injections indefinitely.

Nevertheless, the effect in most patientsis dramatic, says ophthalmologist Edwin M.Stone of the University of Iowa Hospitalsand Clinics in Iowa City, who was not on theresearch team for the trials. He’s observedthat the rogue blood vessels in the eye witherand stop leaking shortly after contact withranibizumab. The vision of one of hispatients improved from significantlyimpaired, 20/100, to near perfect.

“We’re finally getting medical treatmentsin which we figure out the underlying mech-anisms [of a disease] and design elegantways to counteract them, as opposed to trialand error,” Brown says.

Ranibizumab is marketed under thename Lucentis by its maker Genentech ofSouth San Francisco, Calif. —N. SEPPA

Shop Until YouCan’t StopCompulsive buying affectsboth men and women

Talk about buyer’s remorse.A new nationaltelephone survey indicates that nearly 6 per-cent of adults find themselves unable to resistfrequent shopping binges that leave themsaddled with debt, anxiety, and depression.

Buying gone bad, also known as com-pulsive buying, occurs almost as often inmen as in women, says a team led by psy-chiatrist Lorrin M. Koran of the StanfordUniversity School of Medicine.

The new survey offers the best estimateto date for what some mental-health work-ers regard as an addiction to spending

money. Earlier prevalence figures for com-pulsive buying, based on interviews withsmall groups of consumers, ranged from 2 percent to 16 percent. Because womenseek psychiatric treatment for uncontrolled

spending more often thanmen do, scientists previouslypegged it as a predominantlyfemale condition.

“The widespread opinionthat most compulsive buyersare women may be wrong,”Koran says.

He and his colleaguesdescribe their findings in theOctober American Journalof Psychiatry. Koran saysthat he would now like to see

a larger survey that probes the emotionaland social impact of uncontrolled pur-chases on people’s lives.

In 2004, the team conducted roughly 11-minute interviews with 2,513 individu-als, ages 18 and up, contacted randomly byphone. Interviewers asked about cardinalsigns of compulsive buying, such as intru-sive or senseless impulses to buy, frequentpurchases of unneeded or unaffordableitems, and shopping for longer periods thanintended. Questions also touched on finan-cial problems and emotional letdowns afterbuying sprees.

Compulsive buying, as defined by a highscore on a tally of the cardinal signs,occurred in 6 percent of women and 5.5 per-cent of men, regardless of racial or ethnicbackground, Koran’s group says. Compulsivebuyers averaged 40 years of age, comparedwith 49 years for the other participants. Amajority of compulsive buyers reportedannual incomes under $50,000, whereasonly 39 percent of the others reported

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is remarkably different from other treatments.”FREDERICK FERRIS,National Eye Institute

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BUY BUY, BABY A new survey identifiesnearly 6 percent of U.S. adults as compulsivebuyers, who feel depressed or anxious aftershopping binges.

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incomes in that category.Compulsive buyers reported having the

same number of credit cards as other par-ticipants did. However, compulsive buyerstended to stretch credit card limits thin,often to within $100 of the maximum.Compulsive buyers also preferred to makeminimum payments on credit card bal-ances, regardless of their annual incomes.

Prior evidence suggested that compul-sive buyers often suffer from anxiety anddepression. Koran has studied antidepres-sant drugs as treatments for this condition.

Although compulsive buying isn’t cur-rently accepted as a psychiatric disorder, itdeserves consideration as a behavioraladdiction in the next official manual of psy-chiatric diagnoses, slated to appear in 2011,remark psychiatrist Eric Hollander and psy-chologist Andrea Allen, both of the Mt. Sinai School of Medicine in New YorkCity, in a commentary published with theKoran group’s survey.

Studies such as the new survey will bereviewed over the next few years to deter-mine the diagnostic fate of compulsive buy-ing, says psychiatrist Darrel A. Regier, direc-tor of research for the American PsychiatricAssociation in Arlington, Va., which pub-lishes the manual.

Although the Koran team’s survey reliessolely on self-reports, it improves on earlierprevalence estimates of compulsive buying,says anthropologist Shirley Lee of the Uni-versity of Manitoba in Winnipeg. Still, ifthis condition gets labeled as a mental dis-order, researchers may unwisely ignoresocial contributions to compulsive buying,such as easy credit and pervasive advertis-ing, Lee contends.

Uncontrolled buying can’t be isolatedfrom the depression and anxiety that peo-ple experience as a result of conflicting pres-sures to consume and to avoid debt, Leeadds. —B. BOWER

Jet SetAstronomers identify themakeup of quasar streams

The particle jets streaming from the neigh-borhood of a supermassive black hole punchtheir way out of their home galaxies andextend hundreds of thousands of light-yearsbeyond. Astronomers this week reportedthat they have finally identified the parti-cles in the jets as electrons and protons and

have found that those streams of particlescarry much more energy than someastronomers had theorized.

The composition of jets has been debatedever since they were detected in the 1950s.The jets were known to be electrically neu-tral, but astronomers weren’t sure what theywere made of. One theory held that theycontained mainly electrons and their anti-matter partners, positrons. The other the-ory was that the jets were made of electronsand protons. Protons are about 1,800 timesas heavy as positrons.

“The question is very important,” saystheorist Roger Blandford of Stanford Uni-versity, because “jets carry energy andmomentum from the vicinity of the blackhole out into intergalactic space.” By redis-tributing matter and energy, the jets enableblack holes to wield influence beyond theirown galaxies.

Recent studies had hinted that jets mightbe primarily electrons and protons, butastronomers lacked solid evidence. Deter-mining the composition required observa-tions of high-energy X rays, which no tele-scope had clearly recorded.

Rita Sambruna of NASA’s GoddardSpace Flight Center in Greenbelt, Md., andher colleagues used NASA’s recentlylaunched Swift satellite, which is exquis-itely sensitive to energetic X rays, to exam-ine jets emanating from two quasars morethan 10 billion light-years from Earth.

Quasars are the powerful beacons of lightat the cores of galaxies. They’re powered byblack holes that have crushed the equiva-lent of millions to billions of suns into aregion about the size of the solar system.Most quasars have particle jets, which seemto arise from a disk of matter that swirlsaround a supermassive black hole.

“Thanks to the spectra from Swift, wewere able to see all the [elementary] par-

ticles in the jets,” Sambruna says. Her teamfound that the X rays peaked at an energyof 10,000 electronvolts. Using that infor-mation, the team calculated the energy car-ried by particles in the jets.

Computer models developed by Fab-rizio Tavecchio and Gabriele Ghisellini atthe Merate Observatory in Italy indicatethat jets composed of electrons andpositrons would not contain as muchenergy as the X rays indicated. In fact,such jets would fizzle near the black holeinstead of streaming into space. There-fore, the jets are probably made of elec-trons and protons, Sambruna reportedOct. 5 at a meeting of the American Astro-nomical Society in San Francisco.

“What Rita [Sambruna] is saying is thatin her jets, she needs more power. … A pro-tonic jet will carry more power,” commentsBlandford. He adds that the jets probablyalso include pairs of positrons and electrons,as well as photons. “Undoubtedly, all areinvolved [in carrying energy], and there isprobably a transformation from one to theother along the jet,” he says.

Sambruna and her colleagues calculatethat each jet moves at 99.9 percent of thespeed of light and carries as much mass asthat of Jupiter. —R. COWEN

Hot, Hotter, HotClimate seesawed during dinosaur age

Dinosaurs, too, endured climate change.Although scientists had speculated that theworld some 120 million years ago wasunvaryingly hot, climate fluctuated dra-matically, a new report argues. Twice dur-ing a 250,000-year period in the reign of

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BEAMING IMAGE New observations indicate that the jets emanating from a supermassiveblack hole, as seen in this artist’s depiction, are composed of electrons and protons.

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