Until less than 30 years ago, cataract surgery was still a traumatic, almost medieval, process. Old-style cataract surgery involved making a deep incision, and the sutures used to repair the eye afterward were large. To heal properly, the patient had to have his head immobilized with sandbags for a week while he received continual sedation. The slightest movement could cause the eye to collapse irreparably. Often patients would survive this ghastly period of immobility and then develop serious circulatory problems--even fatal blood clots--from the enforced bed rest. But with modern techniques, the incision in the eye is extremely tiny; the procedure can be done in 20 minutes on an outpatient basis, and with no need for sandbags.

The problem for medicare is that a lot more patients are now deemed eligible for cataract surgery as a result of these and other safe new techniques. What is more, the aging of the baby boomers portends a continual rise in the number of cataract sufferers. When Manitoba regionalized its healthcare system in the mid-1990s, the Misericordia Health Centre in central Winnipeg won a contract to provide ophthalmic surgeries to the whole province. One of the contract's stipulations was that the hospital was supposed to centralize and organize the waiting lists for the surgery. It took a while for administrators to even notice the requirement--but when they did, they handed it to eye surgeon Lorne Bellan.

Dr. Bellan, as things turned out, was an ideal choice. "We physicians were aware that the waiting lists were getting longer, and we suspected that some surgeons might have been padding their lists with people who were presenting minimal indications," he says. "We felt it would be a good idea to sort the waiting list when we centralized it, using unbiased tools to assess who really needed surgery most urgently." As it happened, Dr. Bellan had helped develop such a tool in the early '90s.

At that time, a huge international study of cataract procedures found that doctors in industrialized countries were using all kinds of criteria to decide when to go ahead with surgery. Dr. Bellan and others boiled the diagnostic criteria down to a simple set of 14 basic questions: "Do you have trouble driving at night?" "Do you have trouble telling apart the suits and denominations when you play cards?" This little quiz is called the VF-14 (VF is for "visual functioning"), and it generates a score for each patient. That score turns out to predict a patient's self-reported gain in quality of life after the surgery better than any other diagnostic tool--better, in fact, than a doctor does. It is reliable and it will work anywhere in the world, with minor cultural adaptations. In short, it can tell you which patients stand to gain the most from the surgery.

With the help of computer scientists, Dr. Bellan developed a database which contains the VF-14 score for every potential cataract patient in Manitoba. Other data is factored in, too: whether the patient drives, whether sharp vision is important for his job, how long he has already waited for surgery, and so forth. Surprisingly, Dr. Bellan and the ethicists he consulted decided not to favour younger patients in the computer scoring. Moving a 50-year-old ahead of a 95-year-old in the lineup was deemed to be "socially unacceptable."

This may seem puzzling, since older patients are often refused far more needful treatments; 70-year-olds are generally deemed ineligible for organ transplants, for example. Many medical ethicists have argued that age discrimination can be permissible and sometimes even essential in making the best use of scarce resources. If so, why would it be "socially unacceptable" to prefer younger people for this procedure? "Basically, everybody in the program team felt that we would get human rights activists jumping up and down on our backs if we discriminated in this way," says Dr. Bellan. "With a very limited supply of something you can't just go out and buy, like a human heart, a utilitarian approach may make sense. In other areas, it becomes tricky."

An equally large concern was getting the doctors to co-operate with the program. Eye surgeons in Manitoba are sent periodic reports on their patients' waiting-list standing, and they remain free to ignore that information. Most are glad to have it, but one incensed practitioner decried the "Big Brother" spirit of the centralized list and threatened to feed it false VF-14 scores. If he had, however, his data would have stuck out like a sore thumb (and it didn't). Using statistical techniques, it will be easy to see if some foolhardy doctor decides to gum up the computer with false information.

An important benefit of the computerized wait list is that it can be used to generate exact, raw information about waiting times for cataract surgery. This information can be used to calibrate other surveys of wait-times, such as the headline-making and controversial annual survey by the Fraser Institute. "Because of the selection bias in the Fraser questionnaires, their claims about waiting times are often pooh-poohed," notes Dr. Bellan. But in fact, the Fraser's estimates of wait-times for cataract operations in Manitoba turned out to be slightly conservative--which is just what they have always claimed them to be.

The Fraser data said the average was about 18 weeks at a time when the waiting list showed the exact mean wait to be 23. "I think this is another vindication of our methods," says Fraser Institute executive director Michael Walker. "When we compare our studies with academic ones, we find that our estimates are low 84% of the time. This is something the people who accuse us of scaremongering don't seem to understand."