Intraocular Trifocals Outdo Extended Depth for Near Vision
SAN FRANCISCO — Trifocal intraocular lenses offer better near vision, whereas extended depth of focus (EDOF) lenses might be more suitable for older patients, new research suggests.
"There is no perfect lens," said Béatrice Cochener-Lamard, MD, PhD, from Brest University Hospital in France.
The makers of intraocular lenses have been working to develop options that correct presbyopia in patients undergoing cataract surgery. But the lenses do not work well for everyone. Many patients with implanted bifocal intraocular lenses have had unsatisfactory intermediate vision or starbursts, glare, and halos at night.
Cochener-Lamard and her colleagues compared three lenses designed to address these problems: the PanOptix AcrySof IQ from Alcon and the FineVision Micro F from Physiol, both trifocal lenses; and the Tecnis Symfony from Johnson & Johnson, an EDOF lens.
Starbursts, Glare, and HalosIn their study, presented here at the American Academy of Ophthalmology 2019 Annual Meeting, Cochener-Lamard and her colleagues randomly assigned 20 patients (40 eyes) to receive each of the three lenses.
The AcrySof, approved by the US Food and Drug Administration (FDA) in August, features a central biconvex optic, with an inner diffractive zone and an outer refractive zone, and is made of a hydrophobic acrylate and methacrylate copolymer.
Its posterior surface is spherical, and its anterior surface is aspheric, with a diffractive surface on the central 4.5 mm portion of the optic zone. This divides light to create an intermediate-addition power of +2.17 D (60 cm) and a near-addition power of +3.25 D (40 cm). Its 4.5 mm diffractive zone transmits 88% of light to the retina at a 3.0 mm pupil size, which optimizes performance in a wide range of lighting conditions.
The single-piece, fully diffractive trifocal Micro F lens is 25% hydrophilic acrylic, and has an intended addition power of +1.75 D (80 cm) for intermediate vision and a maximum addition power of +3.5 D (40 cm) for near vision. It combines two diffractive profiles to create trifocality and directs 86% of light energy to the retina.
The single-piece, hydrophobic-acrylic, biconvex Symfony lens has a +1.75 D intermediate-addition power. Its achromatic diffractive surface provides low-addition foci that elongate the range of vision from distance to intermediate, and corrects chromatic aberrations of the cornea. In 2016, it became the first EDOF lens approved by the FDA, as reported by Medscape Medical News.
With the two trifocals, surgeons aimed for emmetropia. With the Symfony, they aimed for minimonovision with a difference in refractive power of no more than 0.25 D.
Both monocular and binocular uncorrected near vision acuity were significantly better with the trifocal lenses than with the EDOF lens (P = .002). However, there were no between-group differences in either monocular or binocular uncorrected distance or intermediate visual acuity.
Halos were more common with the AcrySof than with the other two lenses. Glare was most common with the Symfony and least common with the Micro F. Vision loss in mesopic conditions was comparable in the three groups.
|Table. Vision Acuity With the Three Intraocular Lenses|
|Outcome||AcrySof, % (n = 20)||Micro F, % (n = 20)||Symfony, % (n = 20)|
|Binocular uncorrected distance visual acuity >0.6 lines||94.7||100.0||100.0|
|Binocular uncorrected intermediate visual acuity >0.6 lines||53.0||35.0||55.0|
|Binocular Jaeger score 2 uncorrected near visual acuity||95.0||100.0||70.0|
All three lenses achieved their goals of sharp vision — from far to intermediate to near — in all lighting situations, with good contrast sensitivity and tolerable levels of halos and glare.
"Trifocal or EDOF — it's all about compromise," Cochener-Lamard told Medscape Medical News. When the aim of emmetropia was achieved, the trifocal performed best. Although some light was lost, none of the patients had serious complaints or wanted to exchange their trifocal lenses, she added.
EDOF is probably most suitable for elderly patients, those with retinal risk, those who have undergone refractive surgery, and those whose surgeons who are concerned about multifocality, she added.
Some of his patients have had problems with glare, halos, and starbursts. "You have to be careful in examination of the patient, making sure they don't have any corneal problems or retinal problems that might preclude a good result," he told Medscape Medical News. "If there is anything abnormal with the optical system, none of these lenses work well."
He said he is more hesitant than Cochener-Lamard to use the EDOF in patients with retinal risk or who have undergone refractive surgery.
But, he added, he is looking forward to trying the trifocals in his patients, because the data presented make them look like a more attractive alternative to EDOF lenses.
Cochener-Lamard reports relationships with Thea, Santen, Dompe, Cutting Edge, Alcon, Johnson & Johnson, Zeiss, and Hoya. Bailey has disclosed no relevant financial relationships.
American Academy of Ophthalmology (AAO) 2019 Annual Meeting. Presented October 11, 2019.