Department of Ophthalmology & Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States.
Doheny Eye Institute, Los Angeles, California, United States.
Invest Ophthalmol Vis Sci. 2024 Jul 1;65(8):40. doi: 10.1167/iovs.65.8.40.
In aging and early-intermediate age-related macular degeneration (AMD), rod-mediated dark adaptation (RMDA) slows more at 5° superior than at 12°. Using optical coherence tomography angiography (OCTA), we asked whether choriocapillaris flow deficits are related to distance from the fovea.
Persons ≥60 years stratified for AMD via the Age-Related Eye Disease Study's nine-step system underwent RMDA testing. Two adjacent 4.4° × 4.4° choriocapillaris OCTA slabs were centered on the fovea and 12° superior. Flow signal deficits (FD%) in concentric arcs (outer radii in mm, 0.5, 1.5, 2.2, 4.0, and 5.0 superior) were correlated with rod intercept time (RIT) and best-corrected visual acuity (BCVA).
In 366 eyes (170 normal, 111 early AMD, 85 intermediate AMD), FD% was significantly worse with greater AMD severity in all regions (overall P < 0.05) and poorest under the fovea (P < 0.0001). In pairwise comparisons, FD% worsened with greater AMD severity (P < 0.05) at distances <2.2 mm. At greater distances, eyes with intermediate, but not early AMD differed from normal eyes. Foveal FD% was more strongly associated with longer RIT at 5° (r = 0.52) than RIT at 12° (r = 0.39) and BCVA (r = 0.21; all P < 0.0001). Choroidal thickness was weakly associated with longer RIT at 5° and 12° (r = 0.10-0.20, P < 0.05) and not associated with AMD severity.
Reduced transport across the choriocapillaris-Bruch's membrane-retinal pigment epithelium complex, which contributes to drusen formation under the macula lutea (and fovea), may also reduce retinoid resupply to rods encircling the high-risk area. FD% has potential as a functionally validated imaging biomarker for AMD emergence.
在衰老和早中期年龄相关性黄斑变性（AMD）中，5°上方的杆状细胞介导的暗适应（RMDA）比 12°上方的速度慢。我们使用光相干断层扫描血管造影（OCTA），询问脉络膜毛细血管血流不足是否与距黄斑中心凹的距离有关。
通过年龄相关性眼病研究的九步系统对≥60 岁的患者进行 AMD 分层，进行 RMDA 测试。两个相邻的 4.4°×4.4°脉络膜 OCTA 板以黄斑中心凹和 12°上方为中心。在同心弧形（外半径为 0.5、1.5、2.2、4.0 和 5.0mm 处）中测量血流信号缺陷（FD%），并与杆状细胞截距时间（RIT）和最佳矫正视力（BCVA）相关。
在 366 只眼中（正常 170 只，早期 AMD 111 只，中期 AMD 85 只），所有区域的 AMD 严重程度越高，FD%越差（整体 P<0.05），且黄斑中心凹下 FD%最差（P<0.0001）。在两两比较中，FD%随着 AMD 严重程度的增加而恶化（P<0.05），在距离<2.2mm 时差异具有统计学意义。在更大的距离上，只有中间期 AMD 眼与正常眼不同，而早期 AMD 眼与正常眼没有差异。黄斑中心凹 FD%与 5°的 RIT （r=0.52）比 12°的 RIT （r=0.39）和 BCVA （r=0.21；均 P<0.0001）相关性更强。脉络膜厚度与 5°和 12°的 RIT （r=0.10-0.20，P<0.05）呈弱相关，与 AMD 严重程度无关。
黄斑中心凹下的脉络膜毛细血管-布鲁赫膜-视网膜色素上皮复合物的转运减少，可能导致黄斑下（包括黄斑中心凹）出现脂褐质，这也可能减少视黄醇向高风险区域的杆状细胞供应。FD%有可能成为 AMD 发生的一种功能验证的成像生物标志物。
