Premium IOL is not a single risk category. Enhanced monofocals, non-diffractive extended depth-of-focus optics and diffractive multifocal designs each handle light differently, and that difference matters in an eye where contrast sensitivity is already a clinical concern.
How the optics differ
Diffractive multifocal IOLs split incoming light across two or three focal points. The trade-off is a measurable reduction in contrast sensitivity on objective testing. Non-diffractive EDOF designs use wavefront-shaping optics to extend the focal range without splitting light, producing a contrast sensitivity profile much closer to a monofocal lens. Enhanced monofocals modestly extend depth of focus while preserving monofocal-grade contrast.
What the glaucoma evidence shows
The conventional position has been that diffractive optics should be avoided in glaucoma. The published evidence does not entirely support that. In primary angle-closure and primary angle-closure glaucoma, postoperative contrast sensitivity at all five tested spatial frequencies is statistically equivalent between multifocal and monofocal IOL recipients, both groups gain contrast sensitivity from cataract removal itself.¹ What objective testing measures does not always reflect real-world function.
For non-diffractive EDOF in mild open-angle glaucoma, the evidence is more direct. Prospective data on 52 eyes show preserved contrast sensitivity, strong visual acuity outcomes and high satisfaction.² In early glaucoma compared with monofocals, non-diffractive EDOF delivers better intermediate and near vision, significantly higher spectacle independence and significantly higher satisfaction, with rare bothersome photic phenomena.³
The honest answer is that diffractive optics are not categorically wrong in glaucoma, but they raise the threshold of selection and counselling. Non-diffractive EDOF is the easier case to make.
References
- Kitnarong N, Dagvadorj D, Anothaisintawee T. Effect of multifocal intraocular lens on contrast sensitivity in primary angle-closure patients. Siriraj Med J. 2023;75(7):497-504.
- Ferguson TJ, Wilson CW, Shafer BM, Berdahl JP, Terveen DC. Clinical outcomes of a non-diffractive extended depth-of-focus IOL in eyes with mild glaucoma. Clin Ophthalmol. 2023;17:861-868.
- Kerr NM, Moshegov S, Lim S, Simos M. Visual outcomes, spectacle independence, and patient-reported satisfaction of the Vivity extended range of vision intraocular lens in patients with early glaucoma: an observational comparative study. Clin Ophthalmol. 2023;17:1515-1523.
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