功能化OCT成像技术的创新及其在玻璃体手术中膜剥除对视网膜修复和损伤的机理研究

Membrane peeling (epiretinal membrane or internal limiting membrane) during vitrectomy is considered to be a key technique for the treatment of vitreomacular interface(VMI) disease. This project aims to establish the method of quantify the alteration of retinal structure and function in vitreous surgery, and investigate the characteristics of retinal repair and impairment following membrane peeling in the perspective of in vivo imaging perspective. First, we aim to improve the functional OCT fundus imaging platform previously equipped, and the digital image processing software, to establish quantitative parameters related to changes of retinal microstructure and microvasculature. Then to verify the repeatability of the quantitative parameter of fundus imaging of VMI disease patient in supine position. Further, by studying the changes of retinal structure and function before and after intraoperative membrane peeling and postoperative longitudinal follow-up, we investigate the repair and damage characteristics of retinal structure and function owing to membrane peeling. By obtaining the threshold of quantitative parameters in estimating retinal recovery, we study the reversibility of retinal recovery and impairment during surgery. The related factors of postoperative visual function prognosis are also studied. The results of this study can be extended to fundus examinations for unseating patients and children. The analysis method obtained in the current study can provide evaluation reference for the safety of different surgical techniques and instruments. The theoretical results of this study can improve the surgeon's cognition of the operation area, and provide a strong reference for intraoperative surgical methods and postoperative prognosis. The methodology established in this study will promisingly provide a technology platform for clinical diagnosis and intervention research of other fundus diseases.

玻璃体切除术中膜剥除被认为是治疗玻璃体黄斑界面（VMI）疾病的关键技术，其安全性和有效性仍存在争议。本项目旨在建立术中量化视网膜结构和功能改变的分析方法，从在体影像学的角度研究VMI疾病手术中膜剥除对视网膜修复和损伤的特征。首先，改进原先配备的功能化OCT眼底成像平台，建立相关视网膜细微结构和微血管改变的量化参数；验证检测平台用于仰卧位VMI疾病患者眼底成像和相关量化指标的重复性。然后，通过研究术中剥膜前后视网膜结构和功能的改变，并进一步通过纵向随访，研究玻璃体手术中膜剥除对视网膜结构和功能修复和损伤的特征，获得相关量化参数用于判断视网膜状态恢复的分界值，探索术中视网膜修复和损伤的可逆性，以及术后视功能预后的相关因素。本课题的成果可扩展用于不配合坐位患者、儿童的眼底检查，本课题得到的分析方法可进一步为不同手术技术、不同手术器械的安全性提供评估依据，提高术者对手术区域的认知。

本项目发展了一种集成手术显微镜的术中光学相干断层扫描血管造影 (IOCTA) 系统，可实现术中眼底结构和血流造影成像。该系统在商用手术显微镜的基础上，设计了简捷可靠的光机结构，实现了OCT模块与手术显微镜模块的同步聚焦；引入基于逆信噪比和去相关的光学相干血流运动造影（ID-OCTA）算法，实现了高分辨的三维血流灌注成像。为了验证该系统的术中血流成像的可行性，本项目设计了基于兔眼的眼科模拟手术，并在术中全程监测眼底血流灌注状态。所获结果表明，该术中OCTA系统能够实现术中眼底微细结构和血流状态的高分辨率监测，有助于眼科医生客观评价手术过程和预测术后效果，可广泛应用于临床上内眼手术的术中监测和评估。同时，本项目建立了内眼手术中视网膜结构和功能改变的评价体系，可进一步为不同手术技术、不同手术器械的安全性提供评估依据。此外，该功能化OCT成像技术平台可用于患者仰卧位时的视网膜结构和血管形态的高分辨率成像，也可扩展用于不配合坐位患者、儿童的眼底检查。.另外，本项目结合商业OCT研究特发性黄斑前膜和黄斑裂孔等玻璃体黄斑界面疾病患者的术前、术后视网膜细微结构和血流改变。研究得到，（1）特发性黄斑前膜患眼较健康眼BCVA下降，FAZ面积缩小，毛细血管丛中心凹血流密度增加，旁中心凹血流密度减少，反映了血管向中心凹的移位。视力与浅层FAZ面积呈相关性。（2）特发性黄斑裂孔患眼术后黄斑部微血管系统的密度下降，并发现深层血管丛的状态可以预测术后视力结果。这些结果有助于完善玻璃体视网膜手术术中眼底血流改变的理论体系。