Potential of video games for the promotion of neuroadaptation to multifocal intraocular lenses: a narrative review

Multifocal intraocular lenses(IOLs) are currently usually implanted for the treatment of cataracts because they have been proved to be superior to monofocal IOLs with respect to spectacle independence. In turn, they are associated with a higher prevalence of dysphotopsia symptoms that is one of the most common causes of patient dissatisfaction. Neuroadaptation seems to play a major role in the optimal adaptation to multifocal IOLs. In this context, the development of strategies that facilitate the neuroadaptation process to multifocality might be an effective strategy to reduce patients' dissatisfaction. Video games have been proved to be effective for the improvement of visual acuity and for the promotion of neuroplasticity in elderly subjects and other populations with cortical-related visual impairment. This narrative review highlights the physiological potential of video games as a perceptual strategy to improve visual acuity and promote neuroplasticity in patients using multifocalIOLs, although research is still needed to confirm these benefits in this specific population, with only one comparative study to this date providing evidence of them.

Patients’dissatisfaction with multifocal intraocular lenses managed by exchange with other multifocal lenses of diferent optical profles

Background:The aim of the study was to evaluate the outcomes of dissatisfed patients reporting poor visual quality following implantation of multifocal intraocular lenses(MF-IOLs),managed by IOL exchange with another multifocal optical profle.Methods:This is a retrospective series of cases.MF-IOL exchange was done in 15 dissatisfed patients(30 eyes)with the perception of poor visual quality for far distance afected by neuroadaptation failure.Patients underwent a bilateral exchange of a MF-IOL with another MF-IOL of a diferent optical profle.Visual outcomes and complications were analyzed.Questionnaires including Quality of Vision(QoV),Visual Function Index-14(VF-14)and its Rasch-revised version(VF-8R)and a satisfaction questionnaire were also used for outcome evaluation.Results:The mean elapsed time from implantation to explantation-reimplantation was 11.8 months.The QoV scores improved signifcantly across all the three subscales.Visual function improved with a change in VF-14 score from 60.41±24.81 to 90.16±10.91(P<0.001).The VF-8R score improved as well.The uncorrected distance visual acuity improved from 0.24 to 0.12 logMAR after exchange(P<0.001)and corrected distance visual acuity improved from 0.15 to 0.04 logMAR(P<0.001).Safety and efcacy indexes reached 1.46 and 1.16,respectively.Concerning patients’satisfaction following MF-IOL exchange,80%of the patients reported they would have the MF-IOL reimplantation procedure again.Conclusions:Patient dissatisfaction with neuroadaptation failure following MF-IOL implantation can be managed in 80%of our cases by MF-IOL exchange with a diferent MF-IOL optical profle.

Model reference adaptive impedance control for physical human-robot interaction

This paper presents a novel enhanced human-robot interaction system based on model reference adaptive control. The presented method delivers guaranteed stability and task performance and has two control loops. A robot-specific inner loop, which is a neuroadaptive controller, learns the robot dynamics online and makes the robot respond like a prescribed impedance model. This loop uses no task information, including no prescribed trajectory. A task-specific outer loop takes into account the human operator dynamics and adapts the prescribed robot impedance model so that the combined human-robot system has desirable characteristics for task performance. This design is based on model reference adaptive control, but of a nonstandard form. The net result is a controller with both adaptive impedance characteristics and assistive inputs that augment the human operator to provide improved task performance of the human-robot team. Simulations verify the performance of the proposed controller in a repetitive point-to-point motion task. Actual experimental implementations on a PR2 robot further corroborate the effectiveness of the approach.