1. Keiichiro Minami, Hiroko Bissen-Miyajima, Mami Yoshino, Kunihiko Nakamura Department of Ophthalmology Tokyo Dental College Suidobashi Hospital, Tokyo, Japan All authors have no financial interests Early Postoperative Contrast Sensitivity After Diffractive Multifocal IOL Implantation

2. Purpose Recent diffractive multifocal intraocular lenses (MF-IOL) have provided good uncorrected visual acuities for both distance and near visions. In contrast, loss of contrast sensitivity has been a concern in diffractive MF-IOL. 1-3) To our knowledge there has been no study that observed the change of contrast sensitivity during the early postoperative period. In this retrospective study, changes of contrast sensitivity from 1 day to 1 month after implanting diffractive MF-IOLs were evaluated.

3. Subjects Fifty-six eyes of 40 patients who received diffractive MF-IOL by a surgeon (HBM) were enrolled. The following diffractive MF- IOLs were implanted.

4. At preoperative, and 1 day, 1 week and 1 month postoperatively, the following items were evaluated: Manifest spherical equivalent refraction for distance vision Visual acuities (UDVA, CDVA, UNVA, DCNVA, CNVA) Contrast sensitivity measured with CSV-1000 (Vector Vision) at 5 m under 85 cd/m 2. Statistical analysis Change of refraction and VA were examined with Kruskal- Wallis test. Contrast sensitivity at each spatial frequency were examined with one-way ANOVA following Bonferroni/Dunnett test. Methods UDVA: Uncorrected Distance VA; CDVA: Corrected Distance VA; UNVA: Uncorrected Near VA; DCNVA: Distance-Corrected Near VA, CNVA: Corrected Near VA

5. Results: Distance Vision, Refraction & VA No significant change in the early postoperative period.

6. Results: Near Visual Acuity UNVA was significantly improved during 1 month (P=0.03, Kruskal Wallis). Significant difference between 1 day and 1 month (P=0.04, Steel-Dwass test) P=0.04, Steel-Dwass

7. Results: Distance Contrast Sensitivity Significant changes in 6 and 18 cpd (P=0.05, 0.007, ANOVA), but no significant change in 3, 12 cpd. Post-operative contrast sensitivity was improved between 1 day and 1 month at 6 and 18 cpd (P=0.017, 0.002, Dunnet ad-hoc test) log contrast sensitivity cpd: cycle per degree

8. Results: Distance Contrast Sensitivity ZM900 only (N=36) Significant changes in 18 cpd (P=0.05, ANOVA), but no significant change in 3, 6, and 12 cpd. Post-operative contrast sensitivity was improved between 1 day and 1 month at 18 cpd (P=0.015, Dunnet test) log contrast sensitivity

9. Results: Distance Contrast Sensitivity SA60D3 only (N=18) No significant change in the early period. But, there were significant improvements between 1 day and 1 week at 3 and 6 cpd, and 1 day and 1 month at 18 cpd (P<0.05, Dunnet test) log contrast sensitivity

10. No significant change in CDVA and CNVA, but UDVA, DCNVA, and UNVA became stable in 1 month. A previous study reported distance VA shows stabilization after 1 month postoperatively. 4) Between 1 day and 1 week, acute reactions to cornea and intraocular inflammation due to surgery would affect the VA as well as contrast sensitivity. Visual function of MF-IOL implanted eyes need 1 week to 1 month to stabilize. Discussion Visual function of MF-IOL implanted eyes would need 1 week to 1 month to stabilize.

11. Recovery of contrast sensitivity was slightly lower at 6 (SA60D3) and 18 (ZM900) cpd at 1 day. Lower contrast sensitivity found in MF-IOL 1,4) could be caused by multifocality (shown below), or straylight inherent with diffractive MF-IOL, 3) so that the patient may require time to adapt. Discussion Recovery of contrast sensitivity would require increase in visual acuity as well as adaptation to the multifocality. Sharp image with the distance focus Blurred by the near focus

12. Conclusion After the implantation of diffractive multifocal IOL, contrast sensitivity was stabilized between 1 week to 1 month. However, there was a tendency to require a longer time to stabilize at 18 cpd. References 1.Zhao G, Zhang J, Zhou Y, Hu L, Che C, Jiang N. Visual function after monocular implantation of apodized diffractive multifocal or single-piece monofocal intraocular lens Randomized prospective comparison. J Cataract Refract Surg. 2010;36:282-5 2.Yoshino M, Bissen-Miyajima H, Oki S, Minami K, Nakamura K. Two-year follow-up after implantation of diffractive aspheric silicone multifocal intraocular lenses. Acta Ophthalmol, in press. 3.de Vries NE, Franssen L, Webers CA, Tahzib NG, Cheng YY, Hendrikse F, Tjia KF, van den Berg TJ, Nuijts RM. Intraocular straylight after implantation of the multifocal AcrySof ReSTOR SA60D3 diffractive intraocular lens. J Cataract Refract Surg. 2008; 34:957-62 4.Lyle WA, Jin GJ. Prospective evaluation of early visual and refractive effects with small clear corneal incision for cataract surgery. J Cataract Refract Surg. 1996;22:1456-60.