Speakers: Cataract surgeons can transition easily to implanting toric IOLs

By slightly modifying technique and investing in patient selection, surgeons can offer patients enhanced vision and spectacle independence.

Speakers at the American Society of Cataract and Refractive Surgery 2009 meeting emphasized the value of toric IOLs and offered pearls for patient selection and tips on how to incorporate toric IOLs into their practice. Edward Holland, MD, and Lisa B. Arbisser, MD, explained that the technique only differs slightly from a standard cataract procedure and surgeons can easily adapt to the minor changes in preoperative measuring and final IOL alignment. By offering toric IOLs, surgeons can better serve their patients and give them yet another option to achieve their best visual outcomes.

“If you haven’t made the jump to any of the elective IOLs, I would like to convince you that the step into using the toric is a very, very small step and a step that any good cataract surgeon can make,” Dr. Holland said.

Modified cataract technique

Edward Holland

The only difference between a standard cataract procedure and implanting a toric IOL is that surgeons should mark the eye preoperatively and manipulate the IOL postoperatively, explained Dr. Holland, who is a professor of ophthalmology at the University of Cincinnati and director of cornea at the Cincinnati Eye Institute in Ohio.

“The skill set to use the toric IOL is the same skill set we have as cataract surgeons,” he said. “We’re not having to learn a new corneal procedure.”

Surgeons determine spherical power as they normally would, according to Dr. Holland. He suggested using the AcrySof Toric Calculator online (www.acrysoftoriccalculator.com) to select the correct toric IOL power and determine the axis of the IOL.

“Most of us like to then manipulate the axis of the incision to enhance our outcome,” Dr. Holland said. “For instance, if there is residual astigmatism with a temporal incision, the surgeon can move the incision toward the axis of the residual astigmatism and this will enhance the effect. All of these calculations can be plotted preoperatively with the AcrySof Toric Calculator.”

When first using toric IOLs, Dr. Holland suggests correlating predicted astigmatism measurements with IOL Master Ks, manual Ks and topography. Most patients have topography that matches the manual Ks, Dr. Holland said. The cornea should then be marked while the patient is sitting upright because the eye rotates slightly when the patient is lying down, which could cause the clinician to make inaccurate marks. The marks should be made at 3 o’clock and 9 o’clock, and some surgeons make an additional 6-o’clock mark.

“Instead of inserting the lens in any way, shape or form, in any direction circumferentially, we of course want to look for our three little dots, which are lined up with the haptic,” Dr. Arbisser said. Gross alignment is then made so that the viscoelastic can be removed from under the lens, a skill that should be mastered in any case and particularly for this technology, Dr. Arbisser said.

Dr. Arbisser, who teaches cataract and anterior segment surgery worldwide from her practice, Eye Surgeons Associates in Iowa and Illinois and is an adjunct clinical associate professor at Moran Eye Center in Utah, advised surgeons to make sure that all viscoelastic is removed from the posterior chamber before the final positioning of the IOL to prevent capsule capture syndromes and pressure increases and to allow the lens to sit securely.

Patient selection

Patients who have astigmatism and are willing to pay for an elective IOL to gain the benefit of spectacle independence for distance vision will benefit from a toric IOL, according to Dr. Arbisser. A patient with a high degree of astigmatism may not be an ideal candidate for presbyopia-correcting IOLs, but that patient can achieve blended vision by aiming one eye for distance and the other for intermediate. The toric IOL allows for relative spectacle independence for average daily tasks, with patients using glasses only for extreme ranges of vision.

Dr. Arbisser advised surgeons to select patients with regular, and not irregular, astigmatism. Results with the toric IOL in irregular astigmatism are unpredictable, she said.

To ensure that the toric IOL will produce excellent visual results, Dr. Arbisser suggested implanting the IOL only in patients who have an intact or controlled capsule.

“We can meet the patients’ increased expectations because the technology is excellent and the outcomes are excellent as well,” Dr. Holland said.