Published: 18 August 2020

The majority of cataract surgeries performed in the U.S. are done with a local anesthetic and IV sedation. The local anesthesia may be accomplished in one of two ways: either an injection of anesthetic around the eye or anesthetic eye drops placed on the eye, often combined with an injection of a small amount of anesthetic into the front of the eye at the very beginning of surgery. The injection of anesthetic around the eye generally produces a deeper anesthesia for the surgery than the topical method but it also comes with increased risk. There is a very small chance of potentially serious bleeding behind the eye and a rare chance of inadvertent penetration of the back of the eye with the injection needle. The topical anesthesia has lower risk but does not provide quite as deep of an anesthesia, although the overwhelming majority of people having cataract surgery with a topical anesthetic do not experience any significant pain during the procedure. The other difference between the two anesthesias is with that topical anesthesia you maintain your ability to move your eye around whereas with injection anesthesia the eye muscles are temporarily paralyzed so your eye doesn’t move during the surgery. When you have topical anesthesia it is important for you to try to stare straight ahead at the light in the microscope above you. Most people accomplish this quite easily. Along with the anesthetic to the eye, in most cataract surgeries an anesthetist will also give you some mild sedative medication through an IV. This relaxes you but does not put you “out,” although some people do fall asleep during the procedure from the effects of the sedation. Many people who have cataract surgery with IV sedation don’t remember some of the surgery because of the amnesiac effect that occurs from the sedative. This often doesn’t happen when you return for surgery on your second eye. Despite often getting the exact same dose of sedative on the second surgery you have significant less amnesia the second time. This is caused by a quick buildup in tolerance to the medication. When they have their second surgery, many patients feel that the surgery was significantly different than the first time even though it was done exactly the same. The reason is just that you remember more the second time. On rare occasions people need to have general anesthesia to have their cataracts removed. Today, that is mostly done for people who are incapable of cooperating and staying still for the surgery. For everyone who can cooperate it is generally not worth the risks, which include death, to put people to sleep for a surgery that is easily done under a local anesthetic. Article contributed by Dr. Brian Wnorowski, M.D.

Published: 12 August 2020

What Is Intraoperative Aberrometry? Yes, that is a mouthful, but the concept isn’t quite as hard as the name. An Intraoperative Aberrometer is an instrument we can use in the operating room to help us determine the correct power of the implant we put in your eye during cataract surgery. Cataract surgery is the removal of the cloudy natural lens of your eye and the insertion of a new artificial lens inside your eye called an intraocular lens (IOL). The cloudy cataract that we are removing has focusing power (think of a lens in a camera) and when that lens is removed, we need to insert an artificial lens in its place to replace that focusing power. The amount of focusing power the new IOL needs has to match the shape and curvature of your eye. To determine what power of lens we select to put in your eye, we need to measure the shape and curvature of your eye prior to surgery. Once we get those measurements, we can plug those numbers into several different formulas to try and get the most accurate prediction of what power lens you need. Overall, those measurements and formulas are very good at accurately predicting what power lens you should have. There are, however, several eye types where those measurements and formulas are less accurate at predicting the proper power of the replacement lens. Long Eyes: People who are very nearsighted usually have eyes that are much longer than average. This adds some difficulty with the accuracy of both the measurements and the formulas. There are special formulas for long eyes but even those are less accurate than formulas for normal length eyes. Short Eyes: People who are significantly farsighted tend to have shorter-than-normal eyes. Basically, the same issues hold true for them as the ones for longer eyes noted above. Eyes with previous refractive surgery (LASIK, PRK, RK): These surgeries all change the normal shape of the cornea. This makes the formulas we use on eyes that have not had previous surgery not work as well when the normal shape of the cornea has been altered. This is where intraoperative aberrometry comes in. The machine takes the measurements that we do before surgery and then remeasures the eye while you are on the operating room table after the cataract is removed and before the new implant is placed inside the eye. It then presents the surgeon with the power of the implant that the aberrometer thinks is the correct one. Unfortunately, the power that the aberrometer isn’t always exactly right, but with the combination of the pre-surgery measurements and the intra-surgery measurements the overall accuracy is significantly enhanced. The intraoperative aberrometry is also very helpful in choosing the power of specialty lenses like multi-focal and toric lenses. We would encourage you to consider adding intraoperative aberrometry to your cataract surgery procedure if you have either a long or short eye (usually manifested as a high prescription in your glasses) or if you have had any previous refractive surgery.