(Photo by Adam Cairns/AP Photo/The Columbus Dispatch)

Andrew Lam, M.D., is a retinal surgeon, Assistant Professor at Tufts University School of Medicine, and author of “Saving Sight.”

I’m a doctor with a miracle drug. Three of them, in fact. Their names are Avastin, Lucentis and Eylea. I use them to treat the number one cause of blindness in Americans over sixty-five: wet age-related macular degeneration (AMD). Calling them a miracle is no understatement. If your doctor delivers the unlucky news that you’ve developed wet AMD, it means blood vessels under your macula have started to leak or bleed, robbing you of the sight you rely on to read books, see faces, watch TV or drive.

Enter the miracle drugs—eye injections that limit those leaking submacular vessels, giving us our first treatment capable of bringing vision back. But somehow, these drugs have become among the most controversial in all of medicine.

All three treat wet AMD very effectively. Their most significant difference is cost. Lucentis and Eylea cost approximately $2,000 and $1,850 per dose, respectively. Avastin? Only $50.

Medicare covers them all, so retina doctors and their patients are free to choose whichever medication they wish. A recent survey of our field showed that 64.3 percent of us choose Avastin as our first-line drug. Yet about 35 percent of retina specialists continue to use the expensive medicines as their first treatment of choice. Why?

Most likely, because they feel these drugs are better than Avastin. After all, we’re taught to adhere to the ethical duty to “treat patients the way we’d treat our mothers, or ourselves,” right? That’s a mental check of ethics I employ during virtually every patient visit, every single day.

But what if, in addition to an ethical duty to do what we feel is best, we also had an ethical duty to recommend the most cost-effective care?

This isn’t the way it works now. No one questions that Avastin is by far the most cost-effective choice. But I think doctors who choose Lucentis and Eylea do so because they feel any perceived benefit, no matter how small, obligates them to do so. This is what they taught us in medical school, after all. But in a healthcare system with limited resources, the decision to use a medicine that costs $50 or an alternative that costs forty times more has an enormous impact on our collective future.

I’ll never forget the atmosphere at the 2005 meeting where Lucentis’ clinical trial results were first announced. The crowd of typically bored ophthalmologists suddenly came alive with excitement. This drug was going to change everything.

Then we learned the drug’s maker, Genentech, would charge $2,000 for each dose of Lucentis. Treating monthly, as recommended, would cost a jaw-dropping $24,000 per year, per eye.

But then something happened that Genentech didn’t expect. Doctors tried treating with Avastin, another Genentech medicine with the same mechanism of action. And guess what? Studies showed it worked just as well as Lucentis. More recent studies included Eylea, which was shown to match Lucentis’ efficacy for wet AMD.

Doctors who favor the expensive medications do so for a variety of reasons. They may believe patients with certain clinical characteristics respond better to them. Lucentis, Avastin and Eylea are commonly given at 4, 6, and 8-week intervals, respectively—so Eylea could be given less frequently. Avastin is prepared by compounding pharmacies and does not come straight from the company itself. Using Avastin is considered “off-label”, since Genentech did not seek FDA approval for its use in the eye.

There’s also a financial incentive to prescribe more expensive drugs because Medicare reimburses doctors about 4% more than the cost of drugs we administer. But I honestly think most doctors who choose Lucentis and Eylea do so because they sincerely feel they are more beneficial. The question is—do these benefits justify the more expensive choice when the decision from the standpoint of cost-effectiveness is so egregiously wrong?

A 2014 Health Affairs study showed that Medicare, and American taxpayers, could save $18 billion over the next ten years if doctors switched to Avastin. The extra $1,950 paid for every dose of Lucentis could be used for children’s vaccines or health insurance for uninsured Americans or in a multitude of other valuable ways.

I believe doctors should contemplate a new ethical duty: to spend healthcare dollars cost-effectively. Our resources are limited and healthcare costs continue to escalate. Doctors should remain free to prescribe Lucentis and Eylea; but, in most cases, we can fulfill our ethical duty to both patients and society by recommending the most economical choice.

Some physicians and patients may fear these ideas threaten our autonomy. I think if we do not each begin to seriously consider the impact of our decisions on the healthcare system as a whole—if we do not try to contain costs where it is in our power to do so—it won’t be long before our autonomy truly is in peril.

I discuss all three drug options with my patients. I tell them I would happily choose Avastin for myself or my mother. Some choose Eylea or Lucentis, but the majority choose Avastin. And every time they do, I don’t say it, but I feel they’ve made a patriotic choice.