ORA stands for Optiwave Refractive Analysis. It is the only means of intraoperative aberrometry approved in the country.
ORA is designed to deliver superior refractive outcome to patients undergoing cataract surgery. This means treating nearsightedness (Myopia), farsightedness (Hyperopia), and astigmatism at the time of your procedure. For some basic information on these, please refer to the section on Lasik.
How it works
Before understanding how ORA works, we must first understand how myopia and hyperopia are typically treated. Before a patient has cataract surgery, the anterior curvature of their cornea and the anterior-posterior diameter of their eye are measured. This information is entered into equations that allow us to predict the IOL (intraocular lens) power that would suit them best.
ORA adds an additional safety net by taking a refractive measurement of the eye during the course of surgery using infrared light (completely safe for your eye in this context). In less than a minute, ORA takes 40 measurements which allow for a much more reliable measurement of predicted myopia, hyperopia, and astigmatism.
Why Use it?
Well, to put it simply it delivers superior refractive outcomes without being invasive or adding any risk to the procedure
Unlike the traditional methods of simply measuring the corneal curvature and axial length of an eye, ORA factors in posterior corneal astigmatism. And as we’re learning, posterior corneal astigmatism is becoming increasingly recognized as a factor that must be considered for delivering good outcomes.
Lastly, there are some cases in which ORA is particularly useful and consistently offers a clear advantage.
Eyes that have had LASIK or PRK.
These eyes are notoriously unpredictable in terms of refractive outcomes. Traditional formulas that are used cannot reliably account for refractive changes in the structure of the cornea. ORA lets us bypass these formulas and offer patients the best chance of an ideal outcome.
Premium IOLs (intraocular lenses)
It is vital that the correct lens power is chosen for any of these lenses to function properly. ORA maximizes this chance and greatly increases patient satisfaction along the way. In astigmatism correcting lenses, there’s another fold to this. ORA not only helps predict the best lens power but also helps guide positioning to treat the maximum amount of astigmatism. Here are some pictures of ORA guiding lens positioning.
In the top picture, ORA suggests rotating the lens clockwise to maximize astigmatism. The bottom picture was taken after the lens was rotated successfully. NRR just means “No Rotation Recommended” or “Good job”.