Retinal neurodegeneration in patients with type 2 diabetes mellitus without diabetic retinopathy.

In diabetes mellitus (DM) patients retinal complications were typically considered part of a vascular process. Recent research suggests that retinal degeneration in DM might also be caused by a neuropathy that could precede microvascular alterations. The present work reviews the currently available bibliography about neurodegeneration in patients with type 2 DM (DM2) without diabetic retinopathy (DR). In patients with non-severe, early DM2 without DR and good metabolic control visual function parameters show early abnormalities that precede clinical DR (in which we diagnose with a conventional ophthalmological examination). Using optical coherence tomography (OCT) technology, a reduction in macular and peripapillary thickness has been observed in different studies. Recent researches suggest that systemic complications (especially ischaemia) and a possible microvascular alteration eventually contributes to retinal neurodegeneration, which opens the door to new studies that include new techniques for evaluating the microvascularization of the retinal layers.

Neurodegeneración retiniana en pacientes diabéticos tipo 2 sin retinopatía diabética / Retinal neurodegeneration in patients with type 2 diabetes mellitus without diabetic retinopathy

La retinopatía diabética (RD) tradicionalmente se ha considerado parte de un proceso vascular. Investigaciones recientes sugieren que la degeneración de la retina en la diabetes mellitus (DM) podría ser causada también por una neuropatía y que la neurodegeneración retiniana precedería a las alteraciones microvasculares. El presente artículo revisa la bibliografía existente sobre neurodegeneración en pacientes con DM tipo 2 (DM2) sin RD. En los pacientes con DM2 no severa, temprana, con buen control metabólico y sin RD, las pruebas de función visual muestran anormalidades precoces que anteceden a la aparición de la RD clínica (la que diagnosticamos con una exploración oftalmológica convencional). Utilizando la tomografía de coherencia óptica (OCT) se observa que en estos pacientes existe una disminución en el espesor de distintas capas de la retina, tanto en el área macular como peripapilar. Recientes estudios sugieren que las complicaciones sistémicas (especialmente la isquemia) y una posible alteración microvascular contribuyen a la neurodegeneración retiniana, lo que abre la puerta a nuevos estudios que incluyan nuevas técnicas de evaluación de la microvascularización de las capas internas de la retina como la angio-OCT (AU)

In diabetes mellitus (DM) patients retinal complications were typically considered part of a vascular process. Recent research suggests that retinal degeneration in DM might also be caused by a neuropathy that could precede microvascular alterations. The present work reviews the currently available bibliography about neurodegeneration in patients with type 2 DM (DM2) without diabetic retinopathy (DR). In patients with non-severe, early DM2 without DR and good metabolic control visual function parameters show early abnormalities that precede clinical DR (in which we diagnose with a conventional ophthalmological examination). Using optical coherence tomography (OCT) technology, a reduction in macular and peripapillary thickness has been observed in different studies. Recent researches suggest that systemic complications (especially ischaemia) and a possible microvascular alteration eventually contributes to retinal neurodegeneration, which opens the door to new studies that include new techniques for evaluating the microvascularization of the retinal layers (AU)

Functional Evaluation of the Visual Pathway in Patients with Multiple Sclerosis Using a Multifunction Stimulator Monitor.

OBJECTIVES: To assess the capability of the vision monitor unit Monpack One of detecting visual function alterations in patients with multiple sclerosis (MS) and to evaluate the correlation between structural retinal parameters and functional measurements obtained with this device. METHODS: Forty-eight patients with MS and 46 healthy controls were included in a cross-sectional study. All participants underwent a complete functional evaluation of the visual pathway, which included low-contrast visual acuity (LCVA), contrast sensitivity vision (CSV), automated perimetry, multifocal visual evoked potentials (mfVEPs), and pattern electroretinogram (ERG). All tests were performed using the vision monitor unit Monpack One (Metrovision, France), a multifunction stimulator device. Retinal structural measurements were obtained in all subjects using Triton swept source optical coherence tomography (Topcon, Japan). RESULTS: Patients with MS presented reduced low-contrast VA (p < 0.001) and reduced CSV at medium (p=0.001, p=0.013) and low (p=0.001, p=0.002) spatial frequencies. All visual field parameters were found to be altered in MS patients compared with controls (≤0.001). Patients with MS presented lower amplitude of the P100 waveform of the mfVEP in areas corresponding to central (p < 0.001), inferonasal (p=0.001), and inferotemporal (p=0.003) retina. The pattern ERG did not show significant differences. Significant correlations were observed between structural retinal measurements and functional parameters, especially between the inner macular areas and measurements corresponding to contrast sensitivity and perimetry indexes. CONCLUSIONS: Patients with MS present visual dysfunction detectable with the vision monitor unit Monpack One. This device may be a fast and useful tool to provide a full evaluation of axonal damage in patients with multiple sclerosis.