Optical tolerance to rotation of trifocal toric intraocular lenses as a function of the cylinder power. Issue 3 (May 2021)

• Record Type: Journal Article
• Authors: Ruiz-Alcocer, Javier; Lorente-Velázquez, Amalia; de Gracia, Pablo; Madrid-Costa, David
• Is Part Of: European journal of ophthalmology. Volume 31:Issue 3(2021)
• Page Start: 1007
• Page End: 1013
• Publication Date: 2021-05
• Subjects: Corneal topography -- intraoperative complications of cataract surgery -- intraocular lens calculation for primary/secondary intraocular lens -- intraocular lenses -- lens/cataract -- optics/refraction/instruments; Ophthalmology -- Periodicals; Eye -- Diseases -- Periodicals; 617.7005
• DOI: 10.1177/1120672120926845
• Languages: English
• ISSNs: 1120-6721

Abstract

Background: The aim was to assess the impact of 5- and 10-degree rotations in the optical quality of a trifocal toric intraocular lens with different amounts of cylinder. Methods: Two Physiol Toric intraocular lenses with 1.5 and 3.0 D of cylinder were analysed in three different positions: centred, 5 and 10 degrees rotated. The optical quality of the intraocular lenses was evaluated with the PMTF optical bench through specific perpendicular targets. The analysis was performed by the through-focus modulation transfer function curves and the modulation transfer function corresponding to distance vision (0 D of vergence). Results: For a centred situation, the through-focus modulation transfer function curves of both intraocular lenses showed the classical three peaks corresponding to the powers of the two principal meridians of the intraocular lenses. When 5 and 10 degrees of rotation were induced, the three peaks were attenuated in both cases. The case with the intraocular lens with 3.0 D of cylinder and 10 degrees of rotation showed the worst optical quality and a significant loss of trifocality. The modulation transfer function values obtained for distance vision also showed the worst optical quality for the intraocular lens with 3.0 D of cylinder and 10 degrees of rotation. Conclusion: Rotations over 5 degrees decreased the optical quality of trifocal toric intraocular lenses, being this reduction moderate from 5 to 10 degrees for low levels of cylinder (≤1.5 D). For mid-high levels of cylinder (≥3.0 D), rotations over 5 degrees cause a significant loss of optical quality at all object distances.