Kayser Samantha, Vargas Patricia, Mendelsohn Deborah, Han Jorge, Bi Hua, Benavente Alexandra, Bittner Ava K
a College of Optometry, Nova Southeastern University , Fort Lauderdale , FL , USA.
b College of Health Care Sciences, Medical Sonography Program , Fort Lauderdale , FL , USA.
Curr Eye Res. 2017 Nov;42(11):1503-1510. doi: 10.1080/02713683.2017.1338350. Epub 2017 Sep 14.
We evaluated the test-retest repeatability of blood flow velocities in the retrobulbar central retinal artery (CRA) and explored whether reduced blood flow is related to the degree of visual function loss in retinitis pigmentosa (RP) patients with wide range of disease severity.
We measured CRA peak systolic velocity (PSV) and end diastolic velocity (EDV) to calculate mean flow velocity (MFV) in 18 RP patients using color Doppler imaging with spectral flow Doppler (GE Logiq7 ultrasound) twice in each eye at each of two visits within a month. At each of these two visits, we measured ETDRS visual acuity (VA), quick Contrast Sensitivity Function (qCSF), Goldmann visual fields (GVF), 10-2 Humphrey visual fields (HVF), and dark-adaptation at 5° from fixation with the AdaptDx; multifocal electroretinography (mfERG) was obtained at a single visit.
Mean coefficients of variation for PSV, EDV and MFV were 16.1-19.2% for within-visit measurements and 20.1-22.4% for between-visit measures. Across patients, greater visual function loss assessed with VA (p = 0.04), extinguished versus measurable amplitude in ring 1 for mfERG (p = 0.001), and cone-only versus rod function with the AdaptDx (p = 0.002) were statistically significantly correlated with reduced MFV in the CRA when included a multilevel multivariate regression model along with the qCSF and HVF results, which all together accounted for 47% of the total variance in MFV. GVF log retinal areas (V4e and III4e; p = 0.30 and p = 0.95, respectively) and measurable far peripheral vision during GVF testing (p = 0.66) were not significantly related to MFV.
MFV in the CRA decreased with impaired central vision due to loss of both rod and cone function, had good test-retest repeatability, and may serve as a biomarker outcome to determine the potential physiological basis for improvements in RP clinical trials of therapies with indirect effects on blood flow to the retina.
我们评估了球后视网膜中央动脉（CRA）血流速度的重测重复性，并探讨了血流减少是否与疾病严重程度范围广泛的视网膜色素变性（RP）患者的视觉功能丧失程度相关。
我们使用彩色多普勒成像和频谱血流多普勒（GE Logiq7超声），在1个月内的两次就诊时，对18例RP患者的每只眼睛进行两次测量，测量CRA的收缩期峰值速度（PSV）和舒张末期速度（EDV），以计算平均血流速度（MFV）。在这两次就诊时，我们测量了ETDRS视力（VA）、快速对比敏感度函数（qCSF）、Goldmann视野（GVF）、10-2 Humphrey视野（HVF），以及使用AdaptDx在注视点5°处的暗适应；多焦视网膜电图（mfERG）在单次就诊时获得。
PSV、EDV和MFV的平均变异系数在就诊内测量时为16.1%-19.2%，在就诊间测量时为20.1%-22.4%。在所有患者中，当将qCSF和HVF结果纳入多水平多变量回归模型时，用VA评估的更大视觉功能丧失（p = 0.04）、mfERG第1环中熄灭与可测量振幅的对比（p = 0.001），以及AdaptDx测量的仅视锥细胞与视杆细胞功能的对比（p = 0.002），与CRA中MFV降低在统计学上显著相关，这些因素共同解释了MFV总方差的47%。GVF对数视网膜区域（V4e和III4e；分别为p = 0.30和p = 0.95）以及GVF测试期间可测量到的远周边视力（p = 0.66）与MFV无显著相关性。
由于视杆细胞和视锥细胞功能丧失导致的中心视力受损时，CRA中的MFV降低，具有良好的重测重复性，并且可作为生物标志物结果来确定对视网膜血流有间接影响的RP治疗临床试验中改善效果的潜在生理基础。
