Clear lens extraction surgery: Pinpointing the optimal time in glaucoma patients

January 24, 2021
Lynda Charters

The traditional treatment for primary angle-closure (PAC) and PAC glaucoma (PACG) is laser peripheral iridotomy (LPI) to facilitate aqueous outflow followed by medical treatment with drops to decrease the intraocular pressure (IOP).

This article was reviewed by Ruth D. Williams, MD

The traditional treatment for primary angle-closure (PAC) and PAC glaucoma (PACG) is laser peripheral iridotomy (LPI) to facilitate aqueous outflow followed by medical treatment with drops to decrease the intraocular pressure (IOP).

But there may be another option after the EAGLE study,1 a randomly assigned controlled trial, showed that a better initial treatment may be clear lens extraction for some of these patients, according to Ruth D. Williams, MD, during a presentation at the 25th annual Glaucoma Symposium, held during the virtual Glaucoma 360 meeting. Williams is in private practice at the Wheaton Eye Clinic in Wheaton, Illinois.

Watch Dr. Williams's interview on the results of the EAGLE study

The rationale behind the use of clear lens extraction is that the natural crystalline plays an important role in the pathogenesis of PAC and PACG.

Related: Glaucoma devices: Now and in the future

The landmark EAGLE study enrolled 419 patients, of whom 155 had PAC and 263 had PACG. Patients from 30 clinics in 5 countries were randomly assigned to either clear lens extraction (n=208) or to the standard of care (n = 211).

The enrolled patients were all phakic and over 50 years of age. Those with symptomatic cataract, severe glaucoma, or those who had been treated with a previous ocular laser or surgery were excluded.

A third of the enrolled patients had PAC with an IOP that exceeded 30 mm Hg and two-thirds of patients had PACG had an IOP over 21 mm Hg.

The primary outcome measures were the quality of life based on the European Quality of Life-5 Dimensions (EQ-5D) questionnaire that focused on the self-reported health status, the IOP, and the incremental cost-effectiveness ratio/quality-adjusted life-year gained, at 36 months after treatment.

According to Dr. Williams, an analysis of the results showed that the quality of life as scored on the EQ-5D did not decline in the group that underwent lens extractions (0.87 both before and after treatment) but did decline slightly in the group treated with LPI (from 0.87 to 0.84).

Related: Traditional glaucoma surgery in the era of MIGS procedures

In addition, the IOP was 1.3 mm Hg lower, fewer additional surgeries were needed, and fewer medications were needed in the lens extraction group compared with the LPI group: 60.6% of patients achieved control of their IOP after clear lens extraction without the need for medications compared with 21.3% in the LPI group.

The costs associated with lens extractions were higher, but that was offset by the higher quality of life described by patients randomly assigned to the procedure, Dr. Williams said.

The EAGLE investigators concluded that “Clear-lens extraction showed greater efficacy and was more cost-effective than [LPI] and should be considered as an option for first-line treatment.”

LPI remains an option for patients with ACG; however, surgeons are urged to keep an open mind.

“Surgeons should consider clear lens extraction in presbyopes,” Dr. Williams said. “The EAGLE study did not include patients with a visually significant cataract but lens extraction especially makes sense in patients with PAC or PACG and a cataract.”

Related: IOP homeostasis in glaucoma: Looking below the surface

Regarding the usefulness of clear lens extraction, Dr. Williams quoted David Friedman, MD, PhD, who said, “One way to think about this study is [that] it’s moving lens extraction earlier. It’s not exposing the patient to a risk they’re never going to face.”

“The EAGLE study does not make LPI obsolete for patients with PAC and PACG, but it suggests that lens extraction should also be considered for some patients,” Dr. Williams concluded.

See more Glaucoma 360 coverage here

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Ruth D. Williams, MD
E: ruthwilliams@wheatoneye.com
Dr. Williams has no financial interest in this subject matter.



Reference

1. Azuara-Blanco A, Ramsay C, Cooper D, et al. Effectiveness of early lens extraction for the treatment of primary angle-closure glaucoma (EAGLE): a randomised controlled trial. Lancet published Oct 1, 2016; https://doi.org/10.1016/S0140-6736(16)30956-4