Trifocal vs EDOF debate
Trifocal and EDOF IOLs provide good spectacle independence, but which is better?
Greek ophthalmologists debated the relative advantages of trifocal and extended depth of focus intraocular lenses (IOLs) at the 23rd ESCRS Winter Meeting in Athens, Greece.
Petros Smahliou MD, FRCS, FEBO, Athens, Greece, argued in favour of trifocal IOLs, pointing out that they tend to provide better near vision than EDOF IOLs. Moreover, because of their diffractive design they are less prone to haloes and glare than older refractive multifocal IOLs, with no more photic phenomena than EDOF lenses.
“Trifocal IOLs are a good option for the majority of patients. They benefit more from the excellent near vision and reading ability. Newer diffractive trifocals may be better in near vision and quality of vision outcomes, with less risk of haloes than older diffractive and refractive multifocal lenses,” Dr Smahliou said.
Peter Smahliou MD
He cited a recent trial in which 60 patients were randomised to receive one of two types of trifocal IOL or an EDOF lens. It showed that all yielded similar monocular and binocular uncorrected distance visual acuity (UDVA). There were no significant statistical differences for uncorrected intermediate visual acuity (UIVA) but trifocal IOLs outperformed the EDOF IOL in uncorrected near visual acuity.He added that bench test comparisons show that at in trifocal and EDOF IOLs with apertures higher than 2.0mm, the tendency is toward more negative spherical aberrations with the pupil enlargement. However,the bifocal and EDOF IOLs show higher absolute values of spherical aberrations in comparison with the trifocal IOL,especially for large pupil diameters.
“There is no ideal IOL. However, we have to take into account the patients’ needs, so the EDOF lenses have the advantage in the intermediate vision, and the trifocals in the near vision,” he said.
Elisabeth Patsoura MD
Elisabeth Patsoura MD, MRCOphth, Athens, Greece, argued in favour of EDOF IOLs. She noted that there is space for new EDOF designs as multifocal IOLs (MIOLs) traditionally reduce contrast sensitivity, cause photopic phenomena and are less suitable for eyes with concurrent disease. New EDOF technologies control both chromatic and spherical aberrations to improve quality of vision without compromising contrast sensitivity. In addition, pinhole optic models have a potential use with irregular corneas. EDOF IOLs also appear to be more tolerant to defocus than MIOLs.
In the Concerto trial, patients undergoing bilateral implantation of the Symfony EDOF IOL achieved UDVA equal or better than many MIOLs, UIVA similar or better than trifocal IOLs but similar or worse UNVA than that reported with trifocal diffractive models. Nevertheless NVA was comparable with MIOLs when a mini monovision approach was aimed for. In addition, 91% of patients reported no use or occasional use of glasses for distance and near, and 90% reported minimal or no photopic phenomena.
Interestingly, despite worse NVA in most trials the extended range IOL group was no more spectacle dependent than the trifocal group for near tasks.
She added that bench testing requires careful interpretation for their clinical relevance as special eye characteristics and visual cortex response are not taken in account.
Although improvements are needed, EDOF designs are evolving and are likely to surpass MIOLs. Patient selection can never be overstressed.