New stroboscopic system improves accuracy of deformation measurement of crystallin lens submitted to high rotational speed

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PurposeLens elasticity can be calculated from the deformation observed when it is submitted to different rotational speed in a specific device called lens spinner. Up to now, the accuracy of this technique is limited by dynamic blur due to small movements of the lens during rotation and requires expensive high‐speed cameras and intense light sources that can be harmful to the lens. Aim: to assess whether a stroboscopic system could overcome this limit.MethodsThe critical parameter was the synchronization of the light source with the position of the lens on the rotative plate. We thus designed a digital control system combined with a stepper motor that allowed reaching more than 2000 rpm while maintaining an angular accuracy of 0.2 degrees with respect to position of the illumination source. This allowed obtaining sharp 8‐megapixel images with a standard commercially available camera. We analyzed fresh lenses from 6‐month‐ and 3‐year‐old pigs and lenses from human donors (specific retrieval authorization for scientific purpose during corneal donation, from the Agence de la Biomédecine).ResultsLens imaging was obtained by overlaying images of several short flashes: images referenced by their angular position allowed a 360‐degree reconstruction of the geometry of the lens (one image every 45 degrees). The light flux remained moderate with 10 flashes of 100 microseconds with a 20W white LED source. The maximal rotational speed for imaging was 2000 rpm allowing a wide range of investigation as the limit of the resistance of the porcine lens capsule was observed at much higher speeds.ConclusionsCompared to pre‐existing lens spinner systems designed to essentially maintain a stable rotational speed, the fine angular position control combined with the stroboscopic lighting lens spinner strongly improves the reading of the lens’ geometry by an order of magnitude of 10 and will be a very useful device for research in lens biomechanics.