March 2020

ASCRS NEWS

EyeWorld Journal Club
Review of “Prospective randomized comparative trial: Visual performance comparison of two enhanced depth of focus IOLs – Symfony and IC-8”


by Kellyn Bellsmith, MD, Caitlin Kakigi, MD, Nathan Lambert, MD, Nathan Law, MD, Joseph Simonett, MD, Ambar Faridi, MD, Thomas Hwang, MD


Thomas Hwang, MD

Residency program director
Casey Eye Institute
Oregon Health and Science University


Casey Eye Institute, Oregon Health and Science University residents, from left: Nathan Lambert, MD, Kellyn Bellsmith, MD, Joseph Simonett, MD,
Nathan Law, MD, and Caitlin Kakigi, MD

The Symfony and the IC-8 IOLs use very different methods to increase depth of focus. I asked the Oregon Health and Science University residents to review this clinical comparison study that appears in the March issue of JCRS.

—David F. Chang, MD EyeWorld Journal
Club Editor

As IOL designs evolve, patients have an increasing number of options to become “glasses free” after cataract surgery. Emerging technologies, such as multifocal and extended depth of focus IOLs, have been designed to provide functional vision at a variety of working distances. Recent IOL developments have added the use of a small pupillary aperture design to the cataract surgeon’s armamentarium.
The study “Prospective randomized comparative trial: Visual performance comparison of two enhanced depth of focus IOLs – Symfony and IC-8” is the first randomized controlled trial to directly compare outcomes between two extended depth of focus IOL platforms. The Symfony lens (Johnson & Johnson Vision) combines multifocality and an achromatic diffractive echelette design to provide an extended range of vision.1 In contrast, the IC-8 IOL (AcuFocus) is a single-piece acrylic posterior chamber IOL with an embedded circular mask with a small 1.36 mm central aperture.2 Similar small aperture optics have been used as corneal inlays.3 Both lens designs offer patients an extended range of vision while preserving excellent distance acuity after cataract surgery.
This study compared visual acuity and patient satisfaction between the Tecnis Symfony multifocal lens and the IC-8 lens. Thirty-six patients were recruited and randomized into two treatment groups. The IC-8 group had a ZCB00 monofocal lens (Johnson & Johnson Vision) implanted in the dominant eye and an IC-8 lens in the non-dominant eye. The Symfony group had a Symfony multifocal IOL implanted in both eyes. All surgeries were performed by the same surgeon. Target refraction for both groups was plano for the dominant eye and –0.75 D in the non-dominant eye.
Primary endpoints were uncorrected intermediate visual acuity (UIVA) and uncorrected near visual acuity (UNVA). Patients underwent a visual function assessment at 3 months following surgery, including both best corrected and uncorrected monocular and binocular visual acuity at distance, intermediate (67 cm), and near (40 cm) under photopic and mesopic conditions, which represented bright light (i.e., daytime) and low light (i.e., nighttime outdoors and night driving) conditions, respectively. Additionally, patients completed a study-designed questionnaire based on the National Eye Institute Visual Function Questionnaire (NEI-VFQ), a survey initially created to measure quality of life for people with chronic eye diseases. The study questionnaire was developed to assess satisfaction with the visual outcomes of bilateral cataract surgery.
The randomized groups were similar in age and cataract grade and there were no surgical complications or optic decentration noted during follow-up. Deviation from target refraction was low and without significant variability between groups.
Uncorrected binocular distance visual acuity was excellent in both groups, with a small but statistically significant benefit to the IC-8 group under photopic and mesopic lighting conditions (photopic: dominant eye logMAR 0.03 vs. 0.11, p=0.03, non-dominant eye logMAR 0.12 vs. 0.22, p=0.03, both eyes –0.01 vs. 0.07, p=0.02; mesopic: dominant eye 0.15 vs. 0.27, p<0.01, both eyes 0.12 vs. 0.22, p<0.01).
UIVA and UNVA were significantly better in the Symfony group in the dominant eye (which was a Symfony lens in the Symfony group and a ZCB00 lens in the IC-8 group). There was no difference between groups in the non-dominant eye (Symfony lens in the Symfony group, and IC-8 lens in the IC-8 group). Binocularly, there was no difference between UIVA (p=0.35) and UNVA (p=0.14) in the groups.
Results from the study questionnaire suggested slightly higher satisfaction with distance vision among the IC-8 group and with near vision among the Symfony group; however, analysis of the subjective survey results were limited.

Discussion

This prospective study demonstrates that a mini-monovision refractive target with excellent binocular distance visual acuity can be reliably achieved with the IC-8 or Symfony platforms. This type of prospective trial is becoming even more essential as IOL technologies to address presbyopia advance and diversify.
There are multiple possible reasons why the IC-8 group may have had slightly better distance visual acuity. Compared to the monofocal IOL implanted in the dominant eye in the IC-8 group, the light splitting nature of multifocal lens design and relative intolerance to refractive error likely contributed to reduced distance acuity in the Symfony IOL group. While the average refractive outcome of the non-dominant eyes was not statistically different between groups, more eyes in the IC-8 group appeared to have a plano spherical equivalent postoperative refraction. This, and the hypothesis that the IC-8 small aperture design may enlarge the acceptable target refraction range, may contribute to the better distance acuity seen in the non-dominant, low myopia targeted eye in the IC-8 group compared to the Symfony group.
Mesopic conditions for intermediate and near vision were not tested in this study. One might expect a potential decrease in visual acuity at intermediate and near distances with an IC-8 lens under dimmer illumination as the smaller aperture limits the amount of light entering the eye. Future study in this area may be particularly important when counseling patients who enjoy reading before bed or in other mesopic conditions.
Overall, both the Symfony and the IC-8 IOL platforms can provide extended visual range in patients after cataract surgery, with modestly superior distance vision in the IC-8 group. Binocularly, both designs provide comparable intermediate and near vision. When applying study results to the patient in front of you, it is important to recognize that they will most often be using their binocular, rather than monocular, vision. Additionally, when translating these results to patient care, it is important to remember that this study aimed for a mini-monovision refractive goal, and therefore these results may not directly apply when both eyes are targeted for emmetropia. Although the study reported that subjective patient satisfaction was higher in the IC-8 group, it is difficult to make any concrete conclusions without further analysis of the patient satisfaction questionnaire data. However, properly educating patients of the optical advantage and disadvantages of the different lenses will help them identify which lens best fits their specific lifestyle and visual needs. In conclusion, both the Symfony and IC-8 IOL platforms provide excellent options to help patients undergoing cataract surgery to improve their vision and become less reliant on reading glasses.

References

1. Cochener B, Concerto Study Group. Clinical outcomes of a new extended range of vision intraocular lens: International Multicenter Concerto Study. J Cataract Refract Surg. 2016;42:1268–1275.
2. Grabner G, et al. The small-aperture IC-8 intraocular lens: A new concept for added depth of focus in cataract patients. Am J Ophthalmol. 2015;160:1176–1184.
3. Seyeddain O, et al. Femtosecond laser-assisted small-aperture corneal inlay implantation for corneal compensation of presbyopia: two-year follow-up. J Cataract Refract Surg. 2013;39:234–241.

Contact

Hwang: hwangt@ohsu.edu

 

Prospective randomized comparative trial: Visual performance comparison of two enhanced depth of focus IOLs – Symfony and IC-8

Merita Schojai, MD, Tim Schultz, MD, Corinna Jerke, MS-V, Jörg Böcker, Dipl Ing, H. Burkhard Dick, MD J Cataract Refract Surg. 2020;46(3):388–393.

  • Purpose: To compare the visual acuity and satisfaction outcomes of two different concepts of enhanced depth of focus intraocular lenses (EDOF IOLs).
  • Setting: University Eye Hospital Bochum, Germany
  • Design: Prospective randomized comparative clinical trial
  • Methods: This study included a sample of 76 eyes of 38 patients undergoing cataract surgery with the implantation of two different EDOF concepts. In the first group (IC-8 group) a monofocal one-piece Tecnis ZCB00 IOL (Johnson & Johnson Vision) was implanted in the dominant eye and an IC-8 IOL (AcuFocus) was implanted in the non-dominant eye. In the second group (Symfony group) a Tecnis Symfony IOL (Johnson & Johnson Vision) was implanted in both eyes. The target refraction of the dominant eye was emmetropia and slight myopia (mini-monovision; –0.75 D) in the non-dominant eye. Visual and refractive outcomes and patient satisfaction rates were evaluated 3 months after surgery.
  • Results: In both groups no intra- or postoperative complications occurred. The target refraction was reached in both groups without statistically significant differences. The uncorrected distance visual acuity (UDVA, photopic and mesopic light conditions) was excellent in both groups with statistically significant better results in the IC-8 group (logMAR; IC-8 group –0.1 ± 0.07, Symfony group 0.07 ± 0.1, p value 0.02 [photopic]; IC-8 group 0.12 ± 0.09, Symfony group 0.22 ± 0.1, p value <0.01 [mesopic]). Binocular uncorrected intermediate visual acuity (UIVA) and uncorrected near visual acuity (UNVA) were also good in both groups without significant differences (UIVA IC-8 group 0.01 ± 0.07, Symfony group –0.01 ± 0.08, p value 0.35; UNVA IC-8 group 0.14 ± 0.11, Symfony group 0.09 ± 0.08, p value 0.14). Subjective satisfaction was high in both groups.
  • Conclusion: Both EDOF IOLs provided a very good UDVA with superior results in the IC-8 group, good UIVA and UNVA under photopic light conditions. Subjective patient satisfaction was higher in the IC-8 group.
Review of “Prospective randomized comparative trial: Visual performance comparison of two enhanced depth of focus IOLs – Symfony and IC-8” Review of “Prospective randomized comparative trial: Visual performance comparison of two enhanced depth of
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