Abstract
Purpose To analyse and compare the surface topography and roughness of three different types
of diffractive multifocal IOLs.
Methods Using scanning electron microscope (SEM, Inspect F, 5.0 KV, maximum magnification
up to 20,000) and atomic force microscope (AFM, Park Systems, XE-100, non-contact,
area profile comparison, 10 × 10 µm, 40 × 40 µm), the surface quality of the following
diffractive IOLs was studied: the AcrySof IQ PanOptix (Alcon, USA), the AT LARA 829MP
(Carl Zeiss Meditec, Germany), and Tecnis Symfony (Johnson&Johnson Vision, USA). The
measurements were made over three representative areas (central non-diffractive optic,
central diffractive optic, and diffractive step) of each IOL. Roughness profile in
terms of mean arithmetic roughness (Ra) and root-mean-squared roughness (Rq) values were obtained and compared statistically.
Results In SEM examination, all IOLs showed a smooth optical surface without any irregularities
at low magnification. At higher magnification, Tecnis Symfony showed unique highly
regular, concentric, and lineate structures in the diffractive optic area which could
not be seen in the other studied diffractive IOLs. The differences in the measured
Ra and Rq values of the Tecnis Symfony were statistically significant compared to the other
models (p < 0.05).
Conclusion Various different topographical traits were observed in three diffractive multifocal
IOLs. The Ra values of all studied IOLs were within an acceptable range. Tecnis Symfony showed
statistically significant higher surface Ra values at both central diffractive optic and diffractive step areas. Furthermore,
compared to its counterparts, Tecnis Symfony demonstrated highly ordered, concentric
pattern in its diffractive surfaces.
Key words
surface topography - roughness - scanning electron microscope - atomic force microscope
