Premium intraocular lenses in glaucoma- a systematic review

Author: Hong ASY, Ang BCH, Dorairaj E, Dorairaj S.

Geographical coverage: United States of America (USA), Japan, Spain, Australia, and the UK

Sector: Biomedical

Sub-sector: Treatment

Equity focus: Not reported

Study population: Patients with visually significant cataract (unilateral or bilateral) and glaucoma

Review type: Effectiveness review

Quantitative synthesis method: Narrative synthesis

Qualitative synthesis method: Not applicable

Background:

Premium intraocular lenses (IOLs), such as multifocal, extended depth-of-focus, accommodative, and toric IOLs, are popular for providing better unaided vision and reducing dependence on spectacles. Advances in cataract surgery and intraocular lens (IOL) design have led to more predictable results, increasing patient demand. Despite cataracts being the leading cause of reversible vision loss, glaucoma is the top cause of irreversible blindness due to progressive optic neuropathy. Approximately 20% of cataract patients also have glaucoma or ocular hypertension, making IOL choice critical. Surgeons have been cautious with premium IOLs in glaucoma patients due to concerns about contrast sensitivity and visual disturbances. However, technological advancements are improving outcomes, and recent studies are assessing the effectiveness of premium IOLs in glaucomatous eyes.

Objectives:

To consolidate current evidence on surgical outcomes, benefits, and limitations of premium IOL implantation in glaucoma patients, considering visual field defects, glaucoma subtype, ocular surface disease, and postoperative monitoring.

Main findings:

Overall, the authors found that premium IOL implantation in glaucomatous eyes resulted in excellent post-operative vision and high levels of spectacle independence. Specific factors such as glaucoma severity, contrast sensitivity, and the choice of IOL type influenced outcomes.

In their review, which included 12 studies with a total of 399 glaucomatous eyes for qualitative analysis, they noted that the studies were conducted across multiple countries: three in the USA, four in Japan, three in Spain, one in Australia, and one in the UK. The review covered various types of IOLs, including extended depth of focus (EDOF), toric IOLs, multifocal IOLs (MFIOL), and a combination of EDOF, bifocal, and trifocal IOLs.

Five studies reported on spectacle independence in glaucomatous eyes, finding high rates of spectacle independence, particularly for distance vision. Near vision outcomes varied, but some studies reported favourable results, although specific near vision outcomes for glaucomatous eyes were not consistently detailed. The authors found that contrast sensitivity outcomes were generally comparable to healthy subjects, especially for EDOF IOLs. However, one study indicated reduced contrast sensitivity at high spatial frequencies in glaucoma patients implanted with MFIOLs.

Visual acuity outcomes were consistently strong across all 12 studies. Toric IOLs provided significantly better uncorrected visual acuity (uncorrected visual acuity (UCVA)) than non-toric IOLs, particularly in eyes with pre-existing corneal astigmatism. Patients receiving EDOF IOLs demonstrated good uncorrected distance and intermediate visual acuity (uncorrected distance visual acuity (UDVA) and uncorrected intermediate visual acuity (UIVA)). Despite severe visual field damage, toric IOL implantation still achieved excellent post-operative uncorrected vision in patients targeted for emmetropia. Astigmatism outcomes were also favourable, with toric IOLs demonstrating superior post-operative UCVA and greater astigmatic correction than non-toric options. Some studies highlighted the influence of pre-existing corneal astigmatism and surgical technique on refractive predictability.

Methodology:

The authors searched MEDLINE for English studies on patients with significant cataract and glaucoma. They focused on phacoemulsification or femtosecond laser cataract surgery with premium IOL implantation, with or without concurrent glaucoma surgery, and reported surgical outcomes in glaucoma eyes. The search covered the database from inception to June 2023, and reference lists were also screened for relevant articles. Two reviewers independently evaluated potentially relevant articles against eligibility criteria, resolving disagreements through discussion or a third reviewer. Study quality of cohort studies was assessed using the Newcastle–Ottawa Scale (NOS) and non-controlled trials using a modified NOS. Data extraction was done independently by two reviewers, with disagreements resolved similarly. Findings were synthesised narratively.

Applicability/external validity:

The review did not directly address the applicability or external validity of its findings but noted that premium IOLs might benefit specific patients, such as those with glaucoma suspects or early, well-controlled glaucoma. It stressed individualising IOL selection based on disease severity, visual expectations, and glaucomatous visual field defects. The study also highlighted limited evidence for the safety of premium IOLs in advanced glaucoma and recommended caution when combining cataract extraction with certain glaucoma surgeries due to potential impacts on visual outcomes.

Geographic focus:

Included studies were conducted in USA, Japan, Spain, Australia, and the UK.

Summary of quality assessment:

Overall, we have low confidence in the review’s conclusions because of methodological shortcomings: the search strategy was limited to a single database and English‑language publications, increasing the risk of missed evidence and language bias; the authors did not search grey literature systematically; and they did not provide a list of excluded studies, making it difficult to assess selection decisions.