Plank Tina, Benkowitsch Edith M A, Beer Anton L, Brandl Sabine, Malania Maka, Frank Sebastian M, Jägle Herbert, Greenlee Mark W
Institute of Experimental Psychology, University of Regensburg, Regensburg, Germany.
Department of Ophthalmology, University Hospital Regensburg, Regensburg, Germany.
Front Neurosci. 2021 Oct 1;15:718737. doi: 10.3389/fnins.2021.718737. eCollection 2021.
Retinal diseases like age-related macular degeneration (AMD) or hereditary juvenile macular dystrophies (JMD) lead to a loss of central vision. Many patients compensate for this loss with a pseudo fovea in the intact peripheral retina, the so-called "preferred retinal locus" (PRL). How extensive eccentric viewing associated with central vision loss (CVL) affects brain structures responsible for visual perception and visually guided eye movements remains unknown. CVL results in a reduction of cortical gray matter in the "lesion projection zone" (LPZ) in early visual cortex, but the thickness of primary visual cortex appears to be largely preserved for eccentric-field representations. Here we explore how eccentric viewing strategies are related to cortical thickness (CT) measures in early visual cortex and in brain areas involved in the control of eye movements (frontal eye fields, FEF, supplementary eye fields, SEF, and premotor eye fields, PEF). We determined the projection zones (regions of interest, ROIs) of the PRL and of an equally peripheral area in the opposite hemifield (OppPRL) in early visual cortex (V1 and V2) in 32 patients with MD and 32 age-matched controls (19-84 years) by functional magnetic resonance imaging. Subsequently, we calculated the CT in these ROIs and compared it between PRL and OppPRL as well as between groups. Additionally, we examined the CT of FEF, SEF, and PEF and correlated it with behavioral measures like reading speed and eccentric fixation stability at the PRL. We found a significant difference between PRL and OppPRL projection zones in V1 with increased CT at the PRL, that was more pronounced in the patients, but also visible in the controls. Although the mean CT of the eye fields did not differ significantly between patients and controls, we found a trend to a positive correlation between CT in the right FEF and SEF and fixation stability in the whole patient group and between CT in the right PEF and reading speed in the JMD subgroup. The results indicate a possible association between the compensatory strategies used by patients with CVL and structural brain properties in early visual cortex and cortical eye fields.
诸如年龄相关性黄斑变性（AMD）或遗传性青少年黄斑营养不良（JMD）等视网膜疾病会导致中心视力丧失。许多患者通过完整周边视网膜中的假中央凹，即所谓的“首选视网膜位点”（PRL）来代偿这种视力丧失。与中心视力丧失（CVL）相关的广泛偏心注视如何影响负责视觉感知和视觉引导眼动的脑结构仍不清楚。CVL导致早期视觉皮层中“病变投射区”（LPZ）的皮质灰质减少，但初级视觉皮层的厚度在很大程度上保留用于偏心视野表征。在这里，我们探讨偏心注视策略如何与早期视觉皮层以及参与眼动控制的脑区（额叶眼区，FEF；辅助眼区，SEF；以及运动前眼区，PEF）的皮质厚度（CT）测量值相关。我们通过功能磁共振成像确定了32例黄斑营养不良患者和32例年龄匹配的对照者（19 - 84岁）早期视觉皮层（V1和V2）中PRL以及对侧半视野中同样周边区域（OppPRL）的投射区（感兴趣区域，ROI）。随后，我们计算了这些ROI中的CT，并在PRL和OppPRL之间以及组间进行比较。此外，我们检查了FEF、SEF和PEF的CT，并将其与行为指标如阅读速度和PRL处的偏心注视稳定性相关联。我们发现V1中PRL和OppPRL投射区之间存在显著差异，PRL处的CT增加，在患者中更明显，但在对照者中也可见。尽管患者和对照者之间眼区的平均CT没有显著差异，但我们发现整个患者组中右侧FEF和SEF的CT与注视稳定性之间以及JMD亚组中右侧PEF的CT与阅读速度之间存在正相关趋势。结果表明CVL患者使用的代偿策略与早期视觉皮层和皮质眼区的脑结构特性之间可能存在关联。
