The newest iteration of the AcrySof IQ ReStor IOL (Alcon Laboratories, Inc.) has a lower add power at the IOL plane than other AcrySof IQ ReStor IOLs. Because the 2.50 D addition provides approximately 1.75 D of correction at the spectacle plane, the AcrySof IQ ReStor +2.5 IOL (Figure 1) may be a preferable option for patients who require more than good distance vision after cataract surgery. The lens is not designed to replace the ReStor +3.0 but to provide an alternative that appeals to a different patient group.
Although many patients are comfortable wearing reading glasses after surgery, some would prefer to reduce their spectacle dependence for other activities such as shopping or using a handheld device. The key factors to ensure that a patient is satisfied after implantation of a multifocal IOL is to understand his or her basic needs and to select an IOL that works for that specific patient. Information about the patient’s profession and favorite leisure activities is mandatory to guide him or her to the right IOL. For instance, patients who enjoy outdoor activities such as golf, cross-country skiing, hunting, or cycling are well suited for the AcrySof IQ Restor +2.5 IOL. On the other hand, keen readers and patients who want close to total spectacle freedom may be better suited for the AcrySof IQ ReStor +3.0 IOL.
MORE LIGHT FOR DISTANCE VISION
When multifocal IOL optics are designed using diffraction, numerous factors can be adjusted while retaining the general properties of the lens. For example, the lens’ near focal point can be adjusted, as well as the relative amount of light devoted to the far or near image. The ReStor +2.5 distributes more light for distance vision, with fewer diffractive zones and a larger central refractive zone than the +3.0 design (Figure 2). This reduces the potential for visual disturbances such as glare and halos. Additionally, the focal point is approximately 0.50 D further out than the +3.0 (Table 1) to improve intermediate vision. Although near visual acuity is likely lower with this design than the +3.0 design, the +2.5 lens delivers sharp distance vision plus a multifocal range that includes comfortable near vision. It is ideal for patients who want better near and intermediate vision than a monofocal IOL can provide but who are concerned about the potential for visual disturbances associated with diffractive multifocal IOLs.
To date, Dr. Gundersen has implanted the AcrySof IQ ReStor +2.5 IOL in more than 50 eyes. No patients reported needing glasses for distance and computer work, but 25% said they needed glasses when reading small print. These patients were informed in advance about the difference in near vision between the +3.0 and +2.5 lenses, and therefore the outcome was consistent with their postoperative expectations.
Patients with distant-dominant lifestyles can do well with the AcrySof IQ ReStor +2.5. This lens not only provides a greater degree of sharp distance vision compared with the +3.0 lens, but it also decreases spectacle dependence for near vision tasks. We are currently conducting an investigator- initiated clinical trial to quantify the relative differences in near, intermediate, and distance visual acuity and the level of visual disturbances with the +2.5 and +3.0 lenses.
Kjell Gunnar Gundersen, MD, PhD, is in private practice in Haugesund, Norway. Professor Gundersen states that he is a consultant to Alcon Laboratories, Inc. He may be reached at e-mail: firstname.lastname@example.org.
Rick Potvin, MASc, OD, is President of SiV Consulting LLC, a private company providing research support in ophthalmology. Dr. Potvin states that he is a consultant to Alcon Laboratories, Inc. He may be reached at e-mail: email@example.com.