Potential Refractive Error Due To Axial Displacement Of Intraocular Lenses With Clinically Relevant Compression Diameters

To compare the mechanical stability and associated potential refractive error (RE) of nine different intraocular lens (IOL) models using compression diameters that are aligned with the clinically published mean capsular bag diameters (CBD). 

In vitro mechanical bench testing and refractive error calculations (using a schematic eye model) were conducted at Alcon Research, LLC., Fort Worth, Texas, USA.

Nine different single-piece acrylic IOLs (3-5 per model) were tested for axial displacement, optic decentration, optic tilt, and the initial haptic compression force at 9-mm and 10-mm compression diameters under simulated physiological conditions per ISO 11979-3:2012. Potential RE was calculated based on the mean axial displacement observed and using a schematic eye model.

The three different Clareon® optical models (Monofocal, Trifocal and EDOF) had equivalent results, confirming that mechanical stability performance is not affected by the optical design. At 9-mm compression, the measured axial displacement values of the 3 Clareon models were significantly lower than the 6 other models assessed (P < 0.05). At both diameters, the haptic compression force for Clareon was statistically lower than 5 of the other models (P < 0.05). Between the two compression diameters, there were substantial increases in axial displacement and haptic compression force for some of the IOL models. There were no statistical differences among the IOL models studied with respect to either optic decentration or optic tilt. 

Clareon IOL models had statistically lower levels of axial displacement, compression force and potential RE as compared to the other models, which may correlate with consistency of refractive outcomes. Refractive surprises may occur with IOL models that show significant axial displacement.