Monofocal toric lens delivers effective astigmatic correction and more, study results show
This article was reviewed by Alice T. Epitropoulos, MD
Early real-world experience with the spherical aberration (SA) neutral monofocal toric IOL (enVista MX60T, Bausch + Lomb) shows that it delivers predictable, stable correction of refractive astigmatism and provides an improved range of vision with excellent image quality, said Alice T. Epitropoulos, MD.
In a presentation at the ASCRS 2020 virtual annual meeting in May, Epitropoulos, clinical assistant clinical professor of ophthalmology at The Ohio State University Wexner Medical Center in Columbus, reported outcomes achieved in 40 consecutive eyes of 33 patients implanted with the SA neutral monofocal toric IOL.
Thirty-one eyes were targeted for distance (77.5%), and the refractive target in 9 eyes was for monovision (22.5%).
The enVista toric IOL (Photo courtesy of Bausch + Lomb)
At 1 month postsurgery, MRSE was about 0.50 D target in 93% of eyes targeted for distance and 78% of those targeted for monovision.
Results from functional testing showed that 77% of eyes had uncorrected visual acuity (UCVA) of 20/30 or better at distance and intermediate, and J3 or better at near.
“It is interesting that, despite having an essentially plano refraction postoperatively, patients who were targeted for distance had a surprising amount of intermediate and near vision with this monofocal lens. It is also worth noting that quite a few of the eyes in this series had either a history of refractive surgery or ocular comorbidities,” said Epitropoulos, who is in private practice at Ophthalmic Surgeons and Consultants of Ohio in Columbus.
“It seems that by preserving the cornea’s natural positive corneal SA because of its zero SA aspheric optic, the enVista toric IOL can give patients the best of both worlds in terms of good depth of focus and sharper quality of vision,” Epitropoulos said.
Related: ASCRS 2020: Assessing aberration of monofocal toric IOL with enhanced optic recovery, alignment
Seven of the patients in the series underwent bilateral surgery. Epitropoulos performed all of the procedures.
She noted that surgery was delayed for several patients while they were treated for existing ocular surface disease so that reliable topography and keratometry measurements could be obtained for surgical planning.
IOL power calculations were performed using the Barrett Universal II (90%) or SRK-T (10%) formulas. Cylinder power (IOL plane) ranged from 1.25 to 5.00 D (mean 2.06) and was calculated based on the enVista toric calculator.
At 1 month postoperatively, mean MRSE was reduced from –1.41 D preoperatively to –0.44 D, and average cylinder was reduced from 1.22 D preoperatively to 0.19 D.
MRSE averaged –0.26 D (mean targeted MRSE -0.4D) among eyes targeted for distance and -1.03 D (mean targeted MRSE –1.43D) for the monovision eyes.
In the subgroup targeted for distance, distance UCVA was 20/30 or better in 100% of eyes and 20/20 or better in 80%.
Intermediate UCVA was 20/25 or better in 87% of the 31 eyes that had been targeted for distance and in 100% of those targeted for monovision.
Near UCVA was J3 or better in 87% of eyes targeted for distance and J2 or better in 100% of eyes targeted for monovision.
“Keep in mind that our average MRSE for monovision was only about 1 D. Our results reinforce that patients who choose monovision do not require as much anisometropia when using this lens,” Epitropoulos said.
Measurement of lens alignment showed that the toric IOL had excellent rotational stability. In all eyes, lens rotation between postop and both 1 day and 1 month was 5º or less.
“This result is similar to the outcome in the FDA clinical study where less than 6% of lenses rotated more than 5 degrees,” Epitropoulos said.
Choosing a toric IOL
Options for correcting astigmatism during cataract surgery are important considering the prevalence of astigmatism and its effect on visual quality, Epitropoulos said.
“Approximately one-third of all patients who present for cataract surgery have at least 1 D of corneal astigmatism,” she said. “Left untreated, as little 0.5 D of astigmatism can affect the quality of uncorrected vision. Therefore, it is surprising that only 7% of all cataract procedures include implantation of a toric lens.”
In 2020, 3 monofocal toric IOLs were available in the United States. The enVista toric IOL, which was approved in 2018, is the newest of the 3 platforms.
“Its SA neutral aspheric optic is one feature that sets the enVista apart from the other monofocal toric IOLs,” Epitropoulos said. “In addition, the enVista toric IOL is the only toric IOL option on the market that is available in a toric power to treat astigmatism as low as 0.9 D at the corneal plane.”
Alice T. Epitropoulos, MD
Epitropoulos is a consultant and speaker for Bausch + Lomb.