Surgeon prefers toric IOLs to LRIs for astigmatism management

“The bottom line
for me is that toric
IOLs are a safer
and more effective
methodology for
managing corneal
astigmatism at the
time of cataract
surgery”

Edward J. Holland, M.D.

Prevalence of astigmatism prior to cataract surgery
Courtesy of W. Hill, M.D.



AcrySof IQ Toric IOL

The hallmarks of any successful ophthalmic procedure are safety, precision,
predictability, and stability. Because toric IOLs fulfill all of these requirements, they are an ideal addition to the cataract surgeon’s armamentarium, according to Edward J. Holland, M.D., director of Cornea Services, Cincinnati Eye Institute, and professor of ophthalmology, University of Cincinnati.
Dr. Holland said surgeons can improve outcomes for a significant number of cataract patients by treating their corneal astigmatism. He cited a set of unpublished data compiled by Warren E. Hill, M.D., Mesa, Ariz., who found that among 6,000 of his cataract surgery patients, 52.5% had 0.75 D or more of cylinder pre-op and 37.7% had 1.0 D or more.
While limbal relaxing incisions are also an option for reducing cylinder in these patients, Dr. Holland said, “The bottom line for me is that toric IOLs are a safer and more effective methodology for managing corneal astigmatism at the time of cataract surgery.”
Toric IOLs can correct a wide range of astigmatism, including higher levels, which makes them applicable to a larger number of patients compared with LRIs. On average, surgeons can expect to be able to correct a maximum of 1.5 D of cylinder with LRIs. In contrast, an AcrySof IQ Toric IOL (model SN6AT5, Alcon, Fort Worth, Texas) will correct 2 D of astigmatism at the corneal plane. “Furthermore, another problem with LRIs is regression,” Dr. Holland said. “A significant number of patients lose some of the effect as the incision heals. There is no regression of effect with toric IOLs.”

Feeling more in control

The predictability of toric IOLs also sets them apart from LRIs, Dr. Holland said. “With toric IOLs, I know which refractive result I’m going to get. Preoperatively, I can use the AcrySof Toric IOL Calculator (www.acrysoftoriccalcu lator.com, Alcon) to adjust the incision location for the best possible results. Post-operatively, based on clinical trial results and my experience, I can feel confident the lens will not rotate off axis to any significant degree. On the other hand, with LRIs, it is difficult, if not impossible, to exactly control the
length and depth of the incisions and predict each patient’s tissue response to surgery. Several nomograms for improving LRI accuracy are available, but even if the same incisions are skillfully created every time, an over- or under-correction is never out of the question,” he said.
In addition to being less predictable than toric IOLs, relaxing incisions can open the door to complications. Paired LRIs, for example, can sometimes be more than 3 mm long. “When you add incisions, you increase risks to the cornea, such as a neurotrophic effect and epithelial problems,” Dr. Holland explained.

Benefits for surgeons and patients

Dr. Holland feels that LRIs have a place in cataract surgery and he uses them to manage astigmatism. However, a toric IOL is his first choice when he wants to manage astigmatism for the rest of his cataract patients. “As astigmatism correcting tools, LRIs and IOLs are very different,” he said. “To do LRIs you need a diamond knife or a guarded steel blade, and you have to get comfortable making large peripheral incisions and handling any problems that arise. Toric lenses are simpler to adopt. The surgical technique does not change from the routine cataract procedure other than pre-op corneal marking and orienting the lens on the correct axis, both of which are very much a part of the cataract surgeon’s skill set.”
Delivering a high quality of vision and spectacle independence whenever possible are important in today’s era of refractive cataract surgery, Dr. Holland added. Among his patients who have received an AcrySof IQ Toric IOL, more than 97% say they do not need to wear glasses for distance vision. “I have found that my cataract patients understand astigmatism correction, and the AcrySof IQ Toric IOL affords excellent uncorrected distance visual acuity,” he said.“Because the AcrySof IQ Toric IOL optic is now available on an aspheric platform, patients can also experience enhanced overall quality of vision, including improved contrast sensitivity, compared with traditional spherical lenses.”
Four additional powers to the AcrySof Toric family are expected to become available in the U.S. next year. They will give surgeons the ability to correct up to 4 D of astigmatism at the corneal plane.

Contact information
Holland: 859-331-9000 ext. 3064; eholland@fuse.net