Small Aperture IC-8 Extended-Depth-of-Focus Intraocular Lens in Cataract Surgery: A Systematic Review

Author: Sánchez-González JM, Sánchez-González MC, De-Hita-Cantalejo C, Ballesteros-Sánchez A. 

Geographical coverage: Not reported

Sector: Cataract surgery

Sub-sector: Intraocular lens, visual outcomes

Equity focus: Not reported

Study population: Patients with cataract

Review type: Effectiveness review

Quantitative synthesis method: Narrative synthesis

Qualitative synthesis method: Not applicable

Background

Cataracts, a leading cause of visual impairment worldwide, affect millions and are associated with increased anxiety and depression due to the resulting loss of independence. As life expectancy and visual demands rise, more patients seek spectacle independence following cataract surgery. However, pre-existing corneal irregularities, resulting from conditions such as keratoconus, trauma, or prior surgeries, can cause refractive surprises and reduce surgical success. Traditional monofocal intraocular lenses (IOLs) offer sharp distance vision but do not meet visual needs at all distances. Multifocal IOLs extend the range of focus but often introduce photic phenomena and reduce contrast sensitivity. To address these limitations, extended-depth-of-focus (EDOF) technologies like the small-aperture IC-8 lens employ pinhole optics to improve vision at multiple distances while minimising optical side effects.

Objective

To systematically review case series reporting visual outcomes and satisfaction following small aperture IC-8 IOL implantation in patients with cataracts, corneal irregularities, and ocular trauma.

Main findings

The review included twenty-two articles published between 2015 and 2022, encompassing 460 eyes from 443 patients. All were case reports or case series. Maximum postoperative follow-up ranged from 1 to 23.6 months. The mean myopic target for the nondominant small-aperture IC-8 IOL was -0.61 ± 0.44 diopters, ranging from 0.00 to -1.73 diopters.

Visual outcomes demonstrated significant improvements. Postoperative uncorrected distance visual acuity (UDVA) was 20/32 or better in 91.09% of eyes, uncorrected intermediate visual acuity (UIVA) in 81.22%, and uncorrected near visual acuity (UNVA) in 52.08%. However, UNVA results varied widely from 0% to 100% across studies. Patient satisfaction scores averaged 8.23 out of 10. Photic phenomena such as glare and halos were reported but were generally mild, and glare and halo scores were lower in EDOF IOLs than in multifocal IOLs. Complications were infrequent and included hyphema, elevated intraocular pressure, cystoid macular oedema, and posterior capsular opacification, with some cases requiring YAG capsulotomy or IOL exchange. Bilateral implantation was associated with better intermediate and near vision, although it slightly increased photic phenomena and reduced satisfaction in some cases.

Methodology

Searches were conducted in PubMed, Web of Science, Scopus, and the Cochrane Library on 15 July 2022 to identify relevant studies. Inclusion and exclusion criteria were clearly defined. The methodological quality of included studies was assessed using the Quality Assessment Tool for Case Series Studies from the National Heart, Lung, and Blood Institute. The findings were synthesised narratively.

Applicability/external validity

The review did not explicitly discuss external validity. However, limitations affecting generalisability were acknowledged, such as reliance on case reports and small case series, short follow-up periods, and lack of randomised controlled trials. These factors suggest caution when applying findings to broader populations. Further large-scale, long-term studies are needed.

Geographic focus

The review did not apply geographical limits but did not explicitly report the geographic distribution of included studies.

Summary of quality assessment

There is low confidence in the study’s conclusions. While inclusion/exclusion criteria and study quality assessment were appropriate and clearly reported, the review did not provide a list of excluded studies or report reference list checking or author contact. It is unclear how many reviewers were involved in screening and data extraction. Language restrictions were also not discussed.