Clinical Results And Aberration With Pentafocal And Trifocal Diffractive Intraocular Lenses

A new diffractive pentafocal intraocular lens (IOL) has been recently developed, Intensity lens, Hanita Lenses. In this optic design the refractive focus is the intermediate, and 4 additional foci are obtained by diffraction - 2 for distance (-0.75 D and -1.50 D) and 2 for near (+0.75 D and +1.50 D). The optical design aims at reducing the lost light by using twice the harmonic focus principle optimized by Gerchberg–Saxton (GS) iterative algorithm. In this study we compared the refraction, the aberration, and the visual performance obtained with the new  pentafocal IOL and the POD F trifocal IOL implanted bilaterally at cataract surgery.

Vista Vision Clinic, Verona, Italy

Patients with low corneal astigmatism and bilaterally implanted either with the pentafocal Intensity or the trifocal Pod F IOLs were included in this outcome study. They were free from ocular pathologies that could impair vision, had normal ocular surface, and intact posterior capsule. 20 patients per group were included. All the studied lenses are hydrophilic acrylic, with aspherical optics. The 1 to 2 month postoperative visit was considered. The automated and clinical refraction, the distance contrast sensitivity, the defocus curve, the Zyoptix Hartmann-Shack and the OQAS double-pass aberration were reviewed and compared. Postoperative optical disturbances were analysed with a questionnaire and graded 0 to 4.

Automated refraction was more myopic than the clinical refraction by 1.14 D with the pentafocal Intensity IOL, and by 0.14 D with the trifocal POD F IOL (P<0.001). Distance contrast sensitivity was similar in the two groups. The defocus curve was flatter with the Intensity IOL, with CDVA 0.1 Log MAR up to -2.5 D of defocus. Total 5-mm high-order aberration was 0.38±0.09 m (pentafocal) and 0.36±0.11 m (trifocal) (P=NS); spherical aberration was -0.12±0.12 m and -0.09±0.09 m respectively (P=NS). The OSI index was 2.9±1.4 (pentafocal) vs. 2.6±1.5 (trifocal) (P=NS). Patients with the pentafocal IOL had lower night halo (1.05±0.7 vs. 1.56±0.9, P=0.052) and lower night starburst (0.84±0.69 vs. 1.69±0.85, P=0.002) than those with the trifocal IOL.

The automated refractometer measured the refractive intermediate focus of the pentafocal Intensity IOL in this study. The new pentafocal IOL provided similar distance contrast sensitivity as the trifocal IOL, but better (flatter) defocus curve. The aberration profile was similar with either IOL both with the single-pass aberrometer and with the double-pass aberrometer. The patients reported slightly lower night halo and lower starbust dysphotopsia with the pentafocal IOL.