ICLs: Investigators finding robust and stable results over long term

This article was reviewed by Kyle T. Packer, MD

Posterior chamber implantation of implantablecollamer lenses (ICLs) provided robust, stable results in a young population during an 11-year period.

Most of the data are significant out to 8 years of follow-up, according to Kyle T. Packer, MD, who is with the US Army and practicing in Hanover, New Hampshire.

The results were garnered from a retrospective longitudinal study of 3004 eyes implanted with the ICLs at a US military treatment facility from 2008 to 2019.

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All patients underwent standard refractive procedures and measurements preoperatively and postoperatively.

The median patient age was 25 years; 67% of patients were men. The median baseline spherical equivalent (SE) was –5.87 D.

Packer reported that the mean SE turned slightly myopic over the first 7 years postoperatively. The mean uncorrected visual acuity (UCVA) exceeded 20/25 and the mean best-corrected visual acuity (BCVA) exceeded 20/20 in all patients out to postoperative year 7.

ICLs were implanted in patients because of the presence of abnormal topography or moderate or high levels of myopia.

A comparison of the preoperative and postoperative BCVA showed that about 40% of patients had a gain of a minimum of 1 line of BCVA during the first year after implantation, indicating the safety of the ICLs.

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The endothelial cell count decreased over time postoperatively compared with the baseline, which resulted in a significant overall decrease of 14.4% from baseline to the 5-year time point.

Patients had a significant increase in the IOP to the 1-year time point, and decreased from years 2 through 8.

The vault was estimated as a percentage of the corneal thickness. Low vaults were defined as less than 50% of the corneal thickness, ideal vaults from 51% to 200%, and high vaults over 200%. In this patient population, most vaults were considered ideal.

“The trend over time was a decrease in the vault size, especially after year 7, with no vault size over 157% of the corneal thickness,” Packer said.

Adverse events occurred in 1.2% during the 11-year follow-up, which included the formation of visually relevant cataracts, glaucoma, retinal detachment, and traumatic incision opening. The ICLs were removed in 4.5% of eyes in most cases because of low vaults.

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Physicians often use lenses due to abnormal corneal topography or high myopiaThe main takeaways from this study were the following:

(1) ICLs were implanted because of abnormal corneal topography or high myopia;
(2) refractive results associated with the ICLs were robust and stable during the long-term follow-up;
(3) vault size decreased over time, which suggested an increased risk of cataract formation after 7 years;
(4) a decrease in the mean endothelial cell count of about 14.4% at the fifth postoperative year suggested that another study is needed to assess the long-term clinical significance.