Comparison of visual outcomes after implantation of diffractive trifocal toric intraocular lens and a diffractive apodized bifocal toric intraocular lens

Abstract

PurposeThe aim of this study was to compare a new diffractive trifocal toric lens with an apodized diffractive bifocal toric lens in terms of refractive and visual acuity (VA) outcomes, including low-contrast VA (LCVA), as well as the patient’s visual function 3 months after implantation.Patients and methodsThis is a randomized prospective study involving bilateral implantation of a trifocal toric or a bifocal toric lens. At 3 months postoperatively, the subject’s vision was tested both uncorrected and with his/her best distance correction at: distance (4 m), intermediate (63 cm), and near (40 cm). Binocular defocus curves were measured with no correction and with the subject’s best distance correction in place. Quality of vision was measured using the National Eye Institute Visual Function Questionnaire.ResultsA total of 22 patients were enrolled (eleven in each group). There was no statistically significant difference in the absolute change in measured rotation between 1 month and 3 months postoperatively between the two intraocular lens (IOL) groups (P=0.98). At 3 months, the postoperative refraction and distance VA by eye were similar between groups. There was no statistically significant difference in the measured LCVA between groups (P=0.39). The defocus curve showed that at 67 cm, the trifocal toric lens had statistically significantly better VA when compared to the bifocal toric lens. There were no statistically significant differences by group for any of the National Eye Institute Visual Function Questionnaire scores (P>0.26 in all cases).ConclusionThe trifocal toric IOL improved the intermediate vision without negatively impacting visual function and distance, near, or low-contrast VA when compared to a bifocal toric IOL. The toric component of the trifocal lens effectively reduced astigmatism and provided good rotational stability.

Clinical comparison of patient outcomes following implantation of trifocal or bifocal intraocular lenses: a systematic review and meta-analysis

“…2a and b, Table 2, Supplementary Table S3) and analyses including only RCTs did not reveal any statistically difference between the trifocal and bifocal groups (MD −0.03; 95% CI, −0.06 to 0.01; p  = 0.13 for UDVA and MD −0.00; 95% CI, −0.01 to 0.01; p  = 0.78 for CDVA)2345. The quality of the evidence was moderate to high.…”

“…From these 40 citations, 32 studies were excluded for the following reasons: 15 did not fulfill inclusion criteria, 15 studies did not provide primary outcomes, and two were duplications. Four RCTs2345 and four prospective cohorts1678 were ultimately included in this meta-analysis. Figure 1 shows the flow diagram for the search and selection process.…”

“…The eight studies were all conducted in European countries: France4, Norway15, the Netherlands2, the Czech Republic6, and Spain378. Table 1 summarizes the main characteristics of the included studies, and their quality is assessed in Supplementary Tables S1 and S2.…”

“…At present, most multifocal IOLs are bifocal, with only near and far foci; the quality of intermediate viewing activities such as computer use might be insufficient for daily life345. Manufacturers have recently introduced multifocal IOLs that are trifocal in design, providing functional far, intermediate, and near vision2678.…”

“…There have been several studies comparing visual outcomes after the implantation of bifocal and trifocal IOLs in recent years12345678. Some studies support the notion of trifocal IOLs as the next generation of multifocal IOLs, which improve intermediate vision and the continuum of functional vision without impairing distance and near vision567. However, another study reports that bifocal IOLs provide intermediate visual acuity (VA) similar to trifocal IOLs2.…”