Fluid-based accommodating IOL technology achieved “true accommodation” in a pilot study. A multicenter study of the lens is ongoing.
Take-home message: Fluid-based accommodating IOL technology achieved “true accommodation” in a pilot study. A multicenter study of the lens is ongoing.
By Lynda Charters; Reviewed by Louis D. “Skip” Nichamin, MD
Avon, CO-A novel fluid-based accommodative IOL (FluidVision, PowerVision Inc.) has demonstrated true accommodation in a pilot study, with stable results out to 18 months, said Louis D. “Skip” Nichamin, MD.
The goal of the lens design is “true accommodation,” defined as the ability to see at near and distance seamlessly and to maintain the natural mechanism of accommodation, according to Dr. Nichamin, in private practice in Avon, CO.
The body of this lens is made from a proprietary hydrophobic acrylic. The lens and hollow haptics are filled with a proprietary index-matched silicone fluid. The act of accommodation forces fluid from the haptics into the optic, which increases the optic thickness and optical power. During disaccommodation, the fluid flows back into the haptics and the optical power decreases.
The lens is 10 mm in overall diameter with an optic that is 6 mm in diameter. The haptics are 3 mm high and the refractive index is 1.48. In this IOL, the optic is suspended between the haptics.
Twenty patients with the lens implanted at one site in Pretoria, South Africa, were enrolled in the pilot study. Two surgeons performed all of the monocular implants. Patients were followed at 1 day, 1 and 2 weeks, and 1, 3, 6, 12, and 18 months postoperatively to evaluate the accommodation and accommodative amplitude.
The study evaluated refining the implant technique, selecting and refining the accommodation measurement techniques, and demonstrating the safety of the lens.
At 6 months postoperatively, all patients had excellent distance best-corrected visual acuity (average, 20/19) and very good intermediate and near visual acuities of 20/26 and 20/33, respectively. Visual acuity remained stable out to 18 months in the study patients, Dr. Nichamin noted.
The average accommodation by the “push-down method” was 3+ D, as was its defocus range. Both of these measurements remained stable throughout the follow-up period. Patients also showed an average of 2.5 to 3 D of accommodation when induced by pilocarpine.
The excellent distance refraction demonstrates the high optical quality of the lens, according to Dr. Nichamin, who is a medical advisor to PowerVision.
Measurement of visual acuity in a small subset of patients who underwent binocular implantation showed an average of one additional line increase in best distance-corrected near and intermediate visual acuity, according to Dr. Nichamin.
“No clinically relevant complications were associated with the implantation of the IOL,” he said. “Implantation of this [accommodative IOL] is comparable to a standard IOL implantation procedure.
“The objective accommodation met the International Organization for Standardization guidelines to be labeled an accommodative IOL and subjectively the patients, who are best corrected for distance, see far, intermediate, and near and can read without supplemental correction,” Dr. Nichamin said.
A multicenter study of the lens is ongoing.
The multicenter study-being performed at seven centers in South Africa and Germany-began in January and April 2014, respectively, with a goal of completing 115 implantations.
In South Africa, phacoemulsification was performed with manual curvilinear capsulorhexes (CCCs).
In Germany, the procedures are being performed with both manual CCCs and femtosecond laser. Sixty-eight of the 115 implants were completed with 4-mm insertion, and the remainder will be performed with a 3.5-mm insertion system.
Louis D. “Skip” Nichamin, MD
Dr. Nichamin is a medical advisor to PowerVision Inc. and has no financial interest in any surgical instrument mentioned in this report.