IOL study results
Can we create an intraocular lens (IOL) that replicates this mechanism?” asked Jorge L Alió MD, PhD as an animated video of a crystalline lens cycled through the shape transformation of accommodation and relaxation. “Are accommodative IOLs possible?”
Dr Alió presented the results of a prospective study of the accommodative response of an accommodative IOL, the Akkolens Lumina, to delegates at the XXXIII Congress of the ESCRS in Barcelona, Spain. The study included 82 eyes of 58 patients with ages ranging from 43 to 85 years. Fifty-nine eyes were implanted with the Akkolens, while 23 eyes were implanted with the monofocal AcrySof SA60AT IOL.
“The Akkolens Lumina was designed based on the Alvarez principle, in which a two-element varifocal lens changes its focal power by a sliding shift of optical elements in the plane perpendicular to the optical axis,” explained Dr Alió, of Vissum Ophthalmologic Institute, Alicante, Spain.
In this case, the sliding shift is caused by muscular contractions of accommodation.
Before he discussed the results of the study, Dr Alió outlined several conditions for a new accommodative IOL. First, it must operate independently of the capsular bag. Outcomes must be tested by optometrical standards for near (40cm) and intermediate (70cm) vision. Accommodation should be measured by both subjective and objective tests. Further, pseudoaccommodation should be identified, and outcomes must be proven in large, long-term, multicentre studies.
Historically, accommodating IOLs have known three basic approaches. These include a change in axial position of an IOL with single or dual optic; a change in refractive index or power; and a change in the shape or curvature of the lens, which would occur via capsular bag elasticity, via the zonulo-capsular diaphragm or via changes in vitreous-capsular pressure, he explained.
Distance and near visual acuities, defocus curve, and the objective accommodation with the Grand Seiko WAM-5500 autorefractometer were measured. The follow-up was 12 months.
The results demonstrated statistically significant better near visual acuities for the Akkolens in uncorrected near visual acuity and corrected distance near visual acuity (p<0.01). A statistically significant difference was also observed between groups for defocus levels between -4.50 and -0.50D (p<0.01) with better values for the Akkolens.
Both depth of focus and WAM accommodative stimuli of -2.00D, -2.50D, -3.00D and -4.00D were significantly better in eyes that had received the Akkolens.
“The Akkolens Lumina accommodative IOL demonstrated an accommodative response and a depth of focus greater than the monofocal control group,” said Dr Alió.
Jorge L Alió: firstname.lastname@example.org