March 2019

REFRACTIVE

Presentation spotlight
Surgeon shares experience with small aperture lenses


by Stefanie Petrou Binder, MD, EyeWorld Contributing Writer


Sulcus implantation of the XtraFocus 93L (disc diameter 6 mm, pinhole diameter 1.3 mm, total diameter 14 mm)

For highly aberrated eyes, the XtraFocus 93L implant provides a total mask and stable sulcus implantation

IC-8 IOL photographed after implantation (in regredient light)
Source (all): Burkhard Dick, MD

 

New evidence suggests unilateral and bilateral small aperture lenses
provide excellent vision, high patient satisfaction

The 36th Congress of the European Society of Cataract and Refractive Surgeons (ESCRS) featured a wealth of newly published studies that were of great practical interest to refractive surgeons. One such presentation came from Burkhard Dick, MD, professor of ophthalmology and chairman, University Eye Clinic, Bochum, Germany, who discussed his experience with the IC-8 small aperture intraocular lens (AcuFocus, Irvine, California).
“The pinhole effect is something we are all familiar with and use in our daily practice. There are several small aperture options available, however, my experience with the IC-8 IOL showed excellent visual acuity outcomes, with reliable extended depth of focus in all implanted eyes, without light being split to different foci,” Dr. Dick said. “The lens compensated for deviations from the target refraction, doing away with the need for specific and highly elaborate IOL calculation formulas and intraoperative orientation or aberrometry systems. It was forgiving with residual astigmatism of up to 1.5 D. High quality distance vision was slightly decreased but without changing binocular contrast sensitivity. In my experience, there was a low number of symptoms that related to photic phenomena with a high rate of patient satisfaction.”
The IC-8 IOL is a single piece, hydrophobic, 6-mm optic IOL with a 1.36 mm central aperture, a total diameter of 3.23 mm, and a thin mask of PVDF and carbon nanoparticles that is implanted into the capsular bag, allowing the placement of the mask to be far closer to the nodal point. The current recommendation is unilateral implantation in one eye, with the fellow eye receiving a monofocal IOL.

Multicenter European study

Dr. Dick presented the 6-month results of an investigation1 that was conducted at 12 European sites involving 108 patients with bilateral cataracts who received the IC-8 IOL in one eye, with a refractive target of –0.75 D, and an aspheric, colorless, monofocal IOL in the fellow eye with a plano target. Setting a target of 0.75 D of myopia broadened the range of functional near vision by an additional diopter without loss of distance vision, according to the study results.
The study eyes were corrected to plano, achieving 2.25 D of continuous functional range of vision. Six months after implantation, monocular uncorrected visual acuity was 0.87 logMAR for far, 0.83 logMAR for intermediate, and 0.66 logMAR for near, while binocular uncorrected vision was 1.15 logMAR for far, 0.91 logMAR for intermediate, and 0.69 logMAR for near.
According to the study, binocular contrast vision was equivalent in both the IC-8 eyes and the monofocal IOL eyes. Deviation from target refraction was practically a non-issue in IC-8 eyes. “In terms of deviation from target refraction in sphere and cylinder, the IC-8 was forgiving up to 1.0 D of spherical error,” Dr. Dick said. “For corneal astigmatism, I would say that the patient will tolerate up to 1.5 D of deviation. Beyond 1.5 D, we see a small decrease in visual acuity, which is more academic than clinical. We saw no change in visual acuity for far, intermediate, and near vision with up to 1.5 D off target, which is not the case in an eye implanted with a monofocal IOL.”

IC-8: Therapeutic uses

“The most important and appealing approach is the therapeutic use of the device,” Dr. Dick said. “This option allows us to block out scars, corneal irregularities, and aberrated corneas. It is being successfully used for post-RK cases, for which I would not recommend a multifocal or EDOF lens. This is also true for the increasing number of patients who have undergone keratorefractive procedures. In these eyes, we have to expect a greater deviation from target refraction, and therefore, the IC-8 IOL is my standard lens of choice. I have great outcomes in keratoconus eyes and eyes with iris abnormalities after perforating eye injury as well.”
Dr. Dick noted that for highly aberrated eyes, the XtraFocus 93L implant (Morcher, Stuttgart, Germany) with a pinhole diameter of 1.3 mm and a total disc diameter of 6 mm provided a total mask and stable sulcus implantation that was preferable for more extreme cases.
When imaging the retina in eyes with the IC-8 IOL, narrow-angle mode of 30 to 45 degrees works best to provide good quality images. Dr. Dick uses fundus photography and angiography, dilating the pupil for best results.
“Especially interesting is the use of the IC-8 IOL as a therapeutic device. … I think this device has great potential in the area of corneal pathologies including irregularities, aberrations, post-refractive surgery, and iris/pupil pathologies. Retinal visualization surgery is possible with minimal adjustment,” he said.

Patient choice

Dr. Dick described an uncomplicated set of inclusion criteria for IC-8 IOL implantation. “When I counsel patients, I look for corneal astigmatism at or below 1.5 D. There are no handling issues with this lens and no logistics. There is no need for marking the cornea or for intraoperative calculations, intraoperative changes, or the consideration of rotational aspects, compared to toric IOLs. I personally do not address any photic phenomena with patients, like glare or halo, or consider the need for secondary procedures, which I always do if I implant EDOF or multifocal lenses. What I do tell patients, however, is that they may experience a period of adaptation when moving from light to dark rooms, especially in the first weeks to months after surgery,” he said.

Bilateral small aperture implantation

In a patient subset, satisfaction with the results of monocular IC-8 IOL implantation in the first eye prompted the desire for a small aperture implant in the second eye as well. Dr. Dick’s 6-month results with bilateral IC-8 implants revealed no negative effect on distance, intermediate, or near visual acuity, compared to the monocular outcomes, but seemed to further increase the extended depth of focus. “Visual acuity in these patients was even better,” he noted. “Patients do not complain of any visual disturbances. There are new technologies being developed in this direction, so I think it is worthwhile to look at them,” he said.

Reference

1. Dick HB, et al. Prospective multicenter trial of a small-aperture intraocular lens in cataract surgery. J Cataract Refract Surg. 2017;43:956–968.

Editors’ note: Dr. Dick has financial interests with AcuFocus.

Contact information

Dick: burkhard.dick@kk-bochum.de

Surgeon shares experience with small aperture lenses Surgeon shares experience with small aperture lenses
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