Podkowinski Dominika, Sharian Varnousfaderani Ehsan, Simader Christian, Bogunovic Hrvoje, Philip Ana-Maria, Gerendas Bianca S, Schmidt-Erfurth Ursula, Waldstein Sebastian M
Christian Doppler Laboratory for Ophthalmic Image Analysis, Vienna Reading Center, Department of Ophthalmology, Medical University of Vienna, Spitalgasse 23, 1090 Vienna, Austria.
J Ophthalmol. 2017;2017:8148047. doi: 10.1155/2017/8148047. Epub 2017 May 23.
To determine optimal image averaging settings for Spectralis optical coherence tomography (OCT) in patients with and without cataract.
STUDY DESIGN/MATERIAL AND METHODS: In a prospective study, the eyes were imaged before and after cataract surgery using seven different image averaging settings. Image quality was quantitatively evaluated using signal-to-noise ratio, distinction between retinal layer image intensity distributions, and retinal layer segmentation performance. Measures were compared pre- and postoperatively across different degrees of averaging.
13 eyes of 13 patients were included and 1092 layer boundaries analyzed. Preoperatively, increasing image averaging led to a logarithmic growth in all image quality measures up to 96 frames. Postoperatively, increasing averaging beyond 16 images resulted in a plateau without further benefits to image quality. Averaging 16 frames postoperatively provided comparable image quality to 96 frames preoperatively.
In patients with clear media, averaging 16 images provided optimal signal quality. A further increase in averaging was only beneficial in the eyes with senile cataract. However, prolonged acquisition time and possible loss of details have to be taken into account.
确定有无白内障患者使用海德堡视网膜断层扫描仪（Spectralis光学相干断层扫描，OCT）时的最佳图像平均设置。
研究设计/材料与方法：在一项前瞻性研究中，使用七种不同的图像平均设置对白内障手术前后的眼睛进行成像。使用信噪比、视网膜层图像强度分布之间的差异以及视网膜层分割性能对图像质量进行定量评估。对不同平均程度的测量值在术前和术后进行比较。
纳入13例患者的13只眼睛，分析了1092个层边界。术前，在图像平均增加至96帧之前，所有图像质量测量值呈对数增长。术后，平均图像超过16张后，图像质量达到平稳状态，进一步增加平均图像数量并无益处。术后平均16帧所提供的图像质量与术前平均96帧相当。
在屈光介质清晰的患者中，平均16幅图像可提供最佳信号质量。进一步增加平均图像数量仅对老年性白内障患者有益。然而必须考虑采集时间延长和可能的细节丢失问题。
