Is bilateral implantation of an IOL better than contralateral "mixing and matching" of lenses? In one cross-study comparison, postoperative visual outcomes were examined to compare the effectiveness of bilateral implantation of an apodized diffractive IOL versus contralateral implantation of one apodized diffractive IOL and one refractive zonal progressive IOL.
Hong Kong-Using various types of IOLs in the same patient has been touted as a way to achieve better vision correction than implanting the same IOL bilaterally. This concept of "mix and match" is not quite that simple, however, said Rubens Belfort Jr., MD, speaking here at the World Ophthalmology Congress. Dr. Belfort is affiliated with the Vision Institute, Federal University of São Paulo, Brazil.
"Our experience tells us that such decisions depend on individual situations and patient expectations," he said. "In each case, we must understand the patient and adopt his or her expectations."
Dr. Belfort conducted a cross-study comparison of three studies to evaluate bilateral visual outcomes following implantation of presbyopia-correcting IOLs.
The third study consisted of the label information for the apodized diffractive IOL: 69 patients followed up at 6 months.
To be included in any of the three studies, patients had to be aged at least 21 years at the time of surgery and have received a diagnosis of bilateral cataracts. Other inclusion criteria: calculated lens power within the available range; 1 D or less of astigmatism preoperatively, measured by keratometry, in study eye(s); and clear intraocular media other than cataract.
Patients were randomly selected in the study in which they received contralateral implantation of one apodized diffractive IOL and one refractive zonal progressive IOL. Patients in the other two studies were not randomly selected.
The postoperative evaluation conducted by Dr. Belfort included only those criteria that were the same for all three groups.
In comparing the results of the three studies, he and his colleagues examined six criteria: distance visual acuity (VA), uncorrected at 4 m and best-corrected at 4 m; near VA, uncorrected at best distance and distance-corrected at best distance; and intermediate VA, distance-corrected at 60 cm and uncorrected at 60 cm.
They found that although the mixed group that received one apodized diffractive IOL and one refractive zonal progressive IOL had a higher percentage of patients who demonstrated uncorrected distance acuity of 20/20 or better than either of the other two groups, the best-corrected distance acuity was nearly identical across the three studies. "We concluded that there were no advantages to mix and match, or, as the case may be, mix and unmatch," Dr. Belfort said.
Patients in the group that received bilateral apodized diffractive IOLs demonstrated improvements in both uncorrected and distance-corrected near VA compared with the patients who received contralateral implantation of one apodized diffractive IOL and one refractive zonal progressive IOL, however. "This is something we were not expecting," he said.
The same held true for intermediate VA, because the patients who received the apodized diffractive IOL bilaterally demonstrated improvement in intermediate vision compared with patients who received one apodized diffractive IOL and one refractive zonal progressive IOL.
"We often hear how wonderful the mix-and-match concept is, but we didn't find that here," Dr. Belfort said. "The thing to remember is to put patients and their needs and expectations first, in spite of all the technology and all the marketing."