Lauermann J L, Treder M, Heiduschka P, Clemens C R, Eter N, Alten F
Department of Ophthalmology, University of Muenster Medical Center, Domagkstrasse 15, 48149, Muenster, Germany.
Graefes Arch Clin Exp Ophthalmol. 2017 Aug;255(8):1535-1542. doi: 10.1007/s00417-017-3684-z. Epub 2017 May 4.
To evaluate the impact of eye-tracking (ET) technology on optical coherence tomography angiography (OCT-A) image quality and manifestation of motion artifacts in patients with age-related macular degeneration (AMD).
In a prospective trial, multimodal retinal imaging including OCT-A was performed in 30 patients (78.97 ± 9.7 years) affected by different stages of AMD. Central 3 × 3 mm OCT-A imaging was performed four times consecutively in each patient, twice with active, and twice with inactive ET. Parameters for image evaluation were signal strength index (SSI), variability of foveal vessel density (VD), acquisition time, presence of motion artifacts caused by eye movement (blink lines, displacement) and by software correction of eye movement (quilting, stretch artifacts, vessel doubling). Images were evaluated by two independent readers with subsequent senior reader arbitration for presence of artifacts, and an OCT-A motion artifact score (MAS) was calculated.
Eight patients had early and eight patients had intermediate stages of AMD. Four patients had an atrophic late stage and ten patients an exudative stage of the disease. SSI was 53.55 with inactive and 57.18 with active ET (p = 0.0005). Coefficients of variability of VD between the first and second measurement were 8.9% with inactive and 5.7% with active ET. Mean image acquisition time was 15.97 s (active ET: 22.88 s, p < 0.001). Presence of motion artifacts was significantly higher with inactive ET (mean MAS 3.27 vs. 1.93; p < 0.0001). MAS correlated with AMD disease stage [p = 0.0031 (inactive ET) and p < 0.0001 (active ET)] and with SSI (p = 0.0072 and p = 0.0006).
In patients with AMD, active ET technology offers an improved image quality in OCT-A imaging regarding presence of motion artifacts at the expense of higher acquisition time.
评估眼动追踪(ET)技术对年龄相关性黄斑变性(AMD)患者光学相干断层扫描血管造影(OCT-A)图像质量及运动伪影表现的影响。
在一项前瞻性试验中,对30例(78.97±9.7岁)处于不同AMD阶段的患者进行了包括OCT-A在内的多模态视网膜成像检查。在每位患者中连续进行4次中央3×3mm的OCT-A成像,两次采用主动眼动追踪,两次采用非主动眼动追踪。图像评估参数包括信号强度指数(SSI)、黄斑区血管密度(VD)的变异性、采集时间、由眼球运动引起的运动伪影(眨眼线、移位)以及由软件校正眼球运动引起的伪影(拼接、拉伸伪影、血管加倍)。由两名独立阅片者对图像进行评估,随后由资深阅片者对伪影的存在情况进行仲裁,并计算OCT-A运动伪影评分(MAS)。
8例患者处于AMD早期,8例处于中期。4例患者处于萎缩性晚期,10例处于渗出性晚期。非主动眼动追踪时SSI为53.55,主动眼动追踪时为57.18(p = 0.0005)。第一次和第二次测量之间VD的变异系数,非主动眼动追踪时为8.9%,主动眼动追踪时为5.7%。平均图像采集时间为15.97秒(主动眼动追踪:为22.88秒,p < 0.001)。非主动眼动追踪时运动伪影的出现率显著更高(平均MAS 3.27对1.93;p < 0.0001)。MAS与AMD疾病阶段相关[p = 0.0031(非主动眼动追踪)和p < 0.0001(主动眼动追踪)],且与SSI相关(p = 0.0072和p = 0.0006)。
在AMD患者中,主动眼动追踪技术在OCT-A成像中可改善运动伪影的存在情况,提高图像质量,但代价是采集时间更长。