Partial lens refilling to preserve lens accommodation after cataract surgery

The accommodation of the crystalline lens allows for sharp vision in the close and distant range. Conditions such as cataracts can make it necessary to replace the natural tissue with an artificial intraocular lens (IOL), which lacks the ability to accommodate. The alternatives that are currently under investigation include accommodating IOLs or refilling the lens bag with hydrogels. Here, we investigate the possibility to remove and refill only the central part (nucleus) of a cataract lens, thereby preserving its ability to accommodate. This approach avoids damage to the lens cortex to prevent stiffening of the capsular bag—a significant drawback of complete lens refilling. The nucleus of the lenses of porcine eyes was fragmented via fs-laser treatment and removed by phacoemulsification. The lens’s mechanical properties, ray tracing properties and curvature were investigated with an in-house developed measurement setup, including a lens stretching device for simulation of accommodation. This yielded quantifiable data on the transparency, accommodation capabilities and focus shift of treated versus untreated lenses. While native transparency could not yet be achieved, refilled eyes exhibited the same focal shift as non-refilled, indicating functional accommodation. Measurements of the curvature revealed stronger flattening of refilled eyes. Apart from the study of partial lens refill, the stretcher device and respective protocols presented here possess great potential in IOL development, presbyopia research or characterization of model lenses.