It is common knowledge that lens replacement is needed for higher dioptric corrections. Lens replacement, either in addition to or in place of laser ablation, is also needed for the correction of presbyopia. What makes performing lens replacements difficult is the increased demand of patients who wish to be spectacle independent.

More of our patients want not only to get rid of their cataracts and/or their refractive error, but they also want perfect vision at distance and possibly at near. Therefore, modern lens replacement surgeries — for cataract or refractive indications — need to achieve spectacle independence, and as a bonus, compensate for the likely induced higher order aberrations (eg, spherical aberration).

REFRACTIVE PACKAGES
How do we achieve the above mentioned goals for our patients? At my center, we have a term called refractive package where either refractive lens exchange or cataract surgery is packaged with LASIK (performed 1 to 3 months after the lens surgery if fine-tuning or correction of residual refractive error is necessary). If LASIK is required, there is no additional charge to the patient.

There are several options for the lens surgery portion of the refractive package.

Aspheric monofocal IOLs. Monofocal lenses are still the standard, and now aspheric monofocal IOLs (eg, Tecnis aspheric IOL (Advanced Medical Optics [AMO], Santa Ana, California) can fix the spherical aberration of the eye.

The Tecnis aspheric compensates spherical aberration of the cornea, thereby providing a better image contrast and improving night driving. Because the cornea induces spherical aberration, implantation of a conventional IOL does not eliminate the aberration, and it will still persist. Implanting an IOL that compensates for the aberration of the cornea, however, will produce an aberration-free optical system, enhancing image quality and restoring vision especially under low-contrast situations. With this option, patients achieve excellent distance vision and perfect night vision.

Multifocal IOLs. The second option, which is increasingly used, is to replace the crystalline lens with a multifocal IOL to correct presbyopia, too. Patients are spectacle independent, and they are provided with good near and distance vision. The Tecnis aspheric multifocal IOL has a light distribution of 50% distance and 50% near. It also features an aspheric surface that corrects the spherical aberration of the eye. Its near focus is very strong, so every patient can read. The Rezoom IOL (AMO), another IOL that I use, is distant dominant with excellent intermediate vision but somewhat lower near vision. It is very useful in patients who perform predominantly intermediate tasks such as working on a laptop. There is a tradeoff, however, for all multifocal IOLs, as patients will experience some halos, especially at night.

IDEAL PATIENTS
What are the indications for our refractive package? Ideal candidates for multifocal lenses are presbyopic hyperopes with or without cataract. These patients benefit the most from multifocal lenses. High myopes in the presbyopic age are also good candidates for multifocal IOLs, however, low myopes or presbyopes are not good candidates.

An enhancement procedure may be required when multifocal IOLs are implanted if emmetropia was not achieved, as multifocal IOLs will not perform on ametropic eyes. Even small amounts of refractive error or astigmatism will cause unsatisfactory vision and must therefore be corrected to achieve true spectacle independence.

This leads us to part two of the refractive package: customized laser surgery. In my practice, we use the Visx S4 IR Advanced Customvue system (AMO) with iris registration. Iris registration provides a perfect match between the Wavescan measurement and the laser treatment, which is, in my opinion, mandatory in all customized laser procedures.

ACHIEVING SPECTACLE INDEPENDENCE
Modern refractive lens exchange and cataract surgery are great refractive procedures that correct higher order aberrations and provide patients with spectacle independence. One example of a patient who achieved spectacle independence with this refractive package procedure is as follows: A 56-year-old patient with a typical indication of preoperative refraction of +5.50 D was treated with a customized ablation and a Tecnis multifocal IOL. Postoperatively, the patient exhibited some residual refraction. We therefore performed advanced Customvue LASIK on him and achieved a UCVA of 20/20 and J1+. In addition to the correction of refractive error, coma was also significantly reduced.

When approaching patients with or without cataract who want to correct their refractive errors and obtain perfect vision (ie, distance and near), the refractive package option is beneficial. Combining a multifocal or aspheric IOL with wavefront-driven ablations achieve these perfect visual results. LASIK may be used 1 to 3 months after surgery to further correct these errors.

Michael C. Knorz, MD, is medical director of the Freevis LASIK Center Mannheim and professor of ophthalmology at the Faculty of Clinical Medicine Mannheim of the University of Heidelberg, in Germany. He states that he is a consultant to Advanced Medical Optics and Intralase (Irvine, California). Dr. Knorz may be reached at knorz@eyes.de or +49 621 383 3410.