Functional magnetic resonance imaging to assess neuroadaptation to multifocal intraocular lenses

The winner of the 2017 Obstbaum Award for the best original article on the JCRS.

Purpose: To evaluate the use of functional magnetic resonance imaging (MRI) to assess neuroadaptation to multifocal intraocular lenses (IOLs).

Method: Patients with bilateral diffractive IOL implantation after cataract surgery had functional MRI at postoperative intervals of 3 weeks and 6 months. A nonintervention control group was included as proof of concept. Functional stimuli consisted of sinusoidal gratings with threshold contrast and a light source to induce disability glare. Subjective quality of vision and reading performance were assessed and wavefront analyses were performed.

Results: The study comprised 30 patients in the study group and 15 in the control group. Glare decreased the functional MRI signal measured for sinusoidal gratings initially (3 weeks) but not at 6 months (P = .04), which was confirmed by contrast detection under glare improvement (P = .002). Patients showed increased activity of cortical areas involved in visual attention, procedural learning, effortful cognitive control, and goal-oriented behavior in the early postoperative period, which normalized at 6 months. There were no differences in aberrations, Strehl ratio, or modulation transfer function despite significant decreases in questionnaire symptom scores and visual acuity and reading performance improvements. The control group remained unchanged.