應用影像處理於視網膜光學斷層掃描下自動描繪及測量脈絡膜厚度

Application of Image Processing in Automatic Description for Optical Coherence Tomography and Measurement of Choroidal Thickness

Purposes: Currently, many eye diseases have been found to be associated with changes in choroidal thickness. The purpose of our study was to develop an efficient and fully automated method to quantify choroidal thickness using spectral-domain optical coherence tomography (SD-OCT), as it is widely available. Methods: The patients in this study underwent an SD-OCT scan. Choroidal thickness was both manually and automatically measured from the posterior edge of the retinal pigment epithelium (RPE) to the outer border of the choroid at the fovea. The performance of the automatic method was evaluated by comparing the results to those obtained using the manual measurements. Results: A total of 23 eyes from 23 healthy adults were scanned using SD-OCT. The mean macular choroidal thickness by automatic and manual measurements were 164.34±52.72 and 182.50±74.98 μm, respectively. Conclusions: This study presented an efficient method to detect the boundaries of the choroid to measure choroidal thickness. This fully automated method can be effectively applied by ophthalmologists on clinically-available SD-OCT devices for choroid evaluation. 目的：目前發現許多的眼科疾病與患者的脈絡膜厚度變化有關。本篇研究的目的在介紹一個自動且有效率的方法，這方法可應用於此項眼科正確且方便的脈絡膜檢查方式－視網膜光學斷層掃描檢查中脈絡膜厚度數據的量測。方法：所有的患者都是接受頻域式光學同調斷層檢查（SD-OCT）。脈絡膜厚度分別使用手繪及自動化量測，本研究測量黃斑部中央窩從視網膜色素上皮細胞層的外邊界到脈絡膜層的外邊界的厚度。再將自動化量測的結果與手繪測量的結果進行比較。結果：總共23個正常眼睛的頻域式光學同調斷層檢查影像被納入此研究。使用自動化方式測量出的平均脈絡膜厚度為164.34±52.72μm，使用手繪方式測量出的平均脈絡膜厚度為182.50±74.98μm。結論：本篇研究提出一個高效率的方法來幫助醫師偵測脈絡膜的內外邊界，再藉此進一步地量測脈絡膜厚度。這個完全自動化的方式可以有效地應用在臨床頻域式光學同調斷層檢查影像，幫助眼科醫師評估脈絡膜。