Crystalens accommodating lens
Marchini et al reported the mean anterior axial movement of 20 crystalens IOLs to be only 0.33 ± 0.25mm 2004;76-2482).Yet, despite a mean accommodative amplitude of 1.08 ± 0.54 D (range 0-2.25), 86% of patients in this study required no correction for near vision during routine daily activities.The Medennium Smart IOL is a hydrophobic, acrylic IOL that has dimensions (9.5 x 3.5 mm) similar to the natural crystalline lens.
During accommodative effort, the ring haptics are brought together resulting in a forward axial movement of the optic with a resultant increase in the functional power of the lens.
A more recent study further questioned the validity of this lens’s mechanism of action by demonstrating a mean 151 micron backward shift of the crystalens with pilocarpine 2% instillation Despite a lack of evidence supporting substantial axial movement of the crystalens, data from FDA clinical trials revealed that 26% of patients implanted bilaterally with this IOL were able to function completely without glasses, and 74% of patients were able to function either completely or mostly without glasses.
These findings suggest that the accommodating crystalens is a viable alternative to multifocal IOLs in the appropriate patient.
The Human Optics 1CU is a hydrophilic, acrylic, foldable, single-piece lens with a biconvex square-edge optic and 4 modified flexible haptics that allow for forward movement of the optic during accommodative effort (Figure 1).
In a similar study as that performed with the Morcher Bio Comfold IOL, median anterior movement of the Human Optics 1CU after pilocarpine 2% instillation was calculated to result in a refractive change of no more than 0.5 D in most patients 2004;115-1521).