[Flexibility of intraocular lens haptics of various geometry and materials]

The relations between the deformation and resulting resilience of lens haptics with various geometries and made of different materials were studied. While there are no fundamental differences between PMMA and PP haptics with identical geometries, the resilience of soft lenses made of poly-HEMA and silicone rubber subjected to the same deformation is significantly higher. On the basis of such measurements it is possible to estimate stress on the capsular bag during and after implantation. In light of recent publications concerning the prevention of secondary cataract, permanent circular tensioning of the lens capsule appears a desirable goal. This requirement is best satisfied with a material with permanently high elasticity, which tensions the equator of the capsular bag over 360 degrees.