To evaluate the use of functional magnetic resonance imaging (MRI) to assess neuroadaptation to multifocal intraocular lenses (IOLs). Faculty of Medicine, University of Coimbra, Coimbra, Portugal. Prospective case study. 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. 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. Neuroadaptation to multifocal IOLs took place initially through recruitment of visual attentional and procedural learning networks. Thereafter, a form of long-term adaptation/functional plasticity occurred, leading to brain activity regularization toward a non-effort pattern. These findings, which reinforce the crucial role of higher-level brain regions in the perceptual construction of vision, were consistent with functional and questionnaire outcomes and were unrelated to optical properties.

Purpose: To examine the relationship between microaneurysm turnover (formation rate), using a new semi-automatic method (MA-Tracker) based on color fundus photographs, and diabetic retinopathy (DR) progression to clinically significant macular edema (CSME). Methods: In total, 113 patients/eyes with nonproliferative DR (NPDR) were followed up every 6 months for 2 years as controls of the DR clinical trials, and by conventional general and ophthalmological care for the next 8 years (over a total of 10 years’ follow-up). Microaneurysm turnover for the 2 first years was computed using the MA-Tracker. Results: The 17 patients that developed CSME over the 10 years of follow-up presented a microaneurysm formation rate of 9.2 ± 18.2 microaneurysms/year (mean ± SD) during the first 2 years, which was statistically higher than the eyes that did not develop CSME (0.5 ± 1.2 microaneurysms/year, p < 0.001). These 17 patients also presented higher HbA1C levels at baseline (8.5 ± 1.2%) compared to the patients who did not develop CSME (7.3 ± 1.2%, p = 0.001). Conclusions: A high microaneurysm formation rate on color fundus photographs appears to be a good biomarker for DR progression to CSME in type 2 diabetic patients with NPDR.

Purpose: To assess the reliability of microaneurysm turnover, computed from color fundus photographs, in evaluating diabetic retinopathy in patients with type 2 diabetes and nonproliferative retinopathy. Methods: A new method (MA-Tracker) was developed to count microaneurysms by mapping their locations through image co-registration. To compute the reliability of microaneurysm turnover, 3 different graders were asked to earmark microaneurysms on the same set of color fundus photographs. Results: The total numbers of microaneurysms earmarked in each of 5 visits suggest that microaneurysms remain stable over time (p ≥ 0.138). However, an analysis of each microaneurysm showed that only 29.4% remained at the same location. By computing the formation and disappearance rates of microaneurysms (2.3 and 1.7 microaneurysms/year, respectively), a significant turnover of microaneurysms was found. Conclusions: The formation and disappearance rates of microaneurysms obtained from color fundus photographs using MA-Tracker show very good agreement between different graders, and can be used as indicators of microaneurysm turnover in the initial stages of diabetic retinopathy.

Purpose: To analyze the efficacy and safety of topography-guided photorefractive keratectomy (TG-PRK) to treat irregular astigmatism after corneal transplantation. Methods: This was a retrospective observational case series. Eyes with irregular astigmatism after penetrating keratoplasty treated with TG-PRK (Allegretto Wave Eye-Q) with the topography-guided customized ablation treatment protocol were included. All treatments had been planned to correct the topographic irregularities, as well as to reduce the refractive error after neutralizing the induced refractive change. Clinical records, treatment plan, and the examinations performed were reviewed and the following data were collected: corrected and uncorrected distance visual acuities; manifest refraction; topographic parameters, and corneal endothelial cell count. Results: We included 31 eyes [30 patients; mean age 45.0 ± 13.4 (SD) years]. At the last postoperative follow-up (mean 9.2 ± 8.2 months), we observed a significant improvement in corrected (P = 0.001) and uncorrected distance visual acuities (P < 0.001). There was a gain of ≥1 uncorrected distance visual acuity line in 96.8% (n = 30) of the eyes. Similarly, the refractive parameters also improved (cylinder P < 0.001; spherical equivalent P = 0.002). At the last visit, 54.8% (n = 17) of the patients presented a spherical equivalent of ±1 D. The 3-mm topographic irregularity also decreased significantly (P < 0.001). There was no significant variation of the corneal endothelial cell count. Conclusions: This is the largest case series of TG-PRK to treat irregular astigmatism in postcorneal transplantation eyes. Our results confirm that TG-PRK is an efficient treatment, associated with significant improvements of both visual acuity and refractive parameters.

Neuroplasticity refers to the ability of the brain to reorganize the function and structure of its connections in response to changes in the environment. Adult human visual cortex shows several manifestations of plasticity, such as perceptual learning and adaptation, working under the top-down influence of attention. Plasticity results from the interplay of several mechanisms, including the GABAergic system, epigenetic factors, mitochondrial activity, and structural remodeling of synaptic connectivity. There is also a downside of plasticity, that is, maladaptive plasticity, in which there are behavioral losses resulting from plasticity changes in the human brain. Understanding plasticity mechanisms could have major implications in the diagnosis and treatment of ocular diseases, such as retinal disorders, cataract and refractive surgery, amblyopia, and in the evaluation of surgical materials and techniques. Furthermore, eliciting plasticity could open new perspectives in the development of strategies that trigger plasticity for better medical and surgical outcomes.