Department of Ophthalmology, Chungnam National University College of Medicine, Daejeon, Republic of Korea.
Department of Ophthalmology, Konyang University College of Medicine, Daejeon, Republic of Korea.
PLoS One. 2021 Oct 14;16(10):e0258479. doi: 10.1371/journal.pone.0258479. eCollection 2021.
To investigate the effects of axial length (AL) on the peripapillary microvascular density acquired from optical coherence tomography angiography (OCTA).
Retrospective observational study. A total of 111 eyes from 111 normal healthy subjects were examined. The subjects were divided into three groups according to the AL: Group 1 (AL: < 24.0 mm; 35 eyes), Group 2 (AL: 24.0-25.99 mm; 37 eyes), and Group 3 (AL: ≥ 26 mm; 39 eyes). Peripapillary OCTA images were acquired using 6× 6 mm angiography scans, and vessel density (VD) and perfusion density (PD) of the superficial capillary plexus were calculated automatically. VD and PD were compared among the three groups according to the distance from the optic disc (inner and outer rings). Linear regression analyses were also performed to identify clinical factors associated with average VD.
The average ALs of Groups 1-3 were 23.33± 0.57, 25.05± 0.60, and 27.42± 0.82, respectively. Average VD (P = 0.009) and PD (P = 0.029) in the inner ring increased with increasing AL. However, average VD (P < 0.001) and PD (P < 0.001) in the outer ring decreased with AL increased; the same trends were found for the full areas (VD, p<0.001; PD, p = 0.001). Average VDs in the inner and outer rings were not associated (P = 0.938).
Peripapillary VD and PD were significantly associated with AL. Depending on the distance from the disc, peripapillary VDs and PDs of the inner and outer rings were differentially affected by AL. Physicians should therefore consider the effects of AL in the analyses of peripapillary microvasculature.
探讨眼轴（AL）对光相干断层扫描血管造影（OCTA）获得的视盘周围微血管密度的影响。
回顾性观察性研究。共纳入 111 名正常健康受试者的 111 只眼。根据 AL 将受试者分为三组：第 1 组（AL：<24.0mm；35 只眼）、第 2 组（AL：24.0-25.99mm；37 只眼）和第 3 组（AL：≥26mm；39 只眼）。使用 6×6mm 血管造影扫描采集视盘周围 OCTA 图像，并自动计算浅层毛细血管丛的血管密度（VD）和灌注密度（PD）。根据距视盘的距离（内环和外环）比较三组的 VD 和 PD。还进行了线性回归分析，以确定与平均 VD 相关的临床因素。
第 1-3 组的平均 AL 分别为 23.33±0.57、25.05±0.60 和 27.42±0.82。内环中平均 VD（P=0.009）和 PD（P=0.029）随 AL 增加而增加。然而，外环中平均 VD（P<0.001）和 PD（P<0.001）随 AL 增加而降低；全区域也出现了相同的趋势（VD，p<0.001；PD，p=0.001）。内环和外环的平均 VD 之间没有关联（P=0.938）。
视盘周围 VD 和 PD 与 AL 显著相关。视盘周围内、外环的 VD 和 PD 受 AL 的影响程度因距视盘的距离而异。因此，医生在分析视盘周围微血管时应考虑 AL 的影响。
