One Eye Is Good, but Two Are Better
One Eye Is Good, but Two Are Better
Our work is only as good as our trials and our evidence. The evidence that we will use is from the cataract Patient Outcomes Research Team (PORT) study.[1] Mean preoperative vision was 20/83 and mean postoperative vision was 20/27, so we are looking at a utility change from 20/83 to 20/27. We use a 13-year model (obtained by taking the mean age from the study and adding up to life expectancy). We found after crunching those numbers that over that 13-year period, cataract surgery conferred a gain of 1.62 QALYs. This is hard to appreciate by itself, but if you convert that to the percentage gain in QOL, it comes out to 20.8%. That is the same as when we did a study headed up by Brandon Busbee[2] from our group. If you do both eyes (bilateral cataract surgery), you bump up the quality gain to 2.8, and the percentage improvement in QOL comes up to 36.2%.
What do these numbers mean? Is that a good number? They are great, but let me give you some comparisons. For the sake of comparison, when Zollinger-Ellison syndrome is treated with proton pump inhibitors, the QOL gain is 38%. Treating depression is about the same. Single-eye cataract surgery is about 20% (similar to treatment of glaucoma with timolol). For antihypertensive therapies, the QOL gain is 6%-9%, depending on which drug you use. Many people are on statins for hyperlipidemia. That improvement in QOL is 3%-5%. So you can see that for cataract surgery, that 20% for a single eye and 36% for the second eye is an amazing number. It's good to be able to quantify it. That is patient value.
