Kalitzeos Angelos, Michaelides Michel, Dubra Alfredo
Institute of Ophthalmology, University College London, London, United Kingdom.
National Institute for Health and Care Research, Biomedical Research Centre, Moorfields Eye Hospital, London, United Kingdom.
Front Ophthalmol (Lausanne). 2024 Mar 13;4:1349297. doi: 10.3389/fopht.2024.1349297. eCollection 2024.
Non-confocal split-detection imaging reveals the cone photoreceptor inner segment mosaic in a plethora of retinal conditions, with the potential of providing insight to ageing, disease, and response to treatment processes, , and allows the screening of candidates for cell rescue therapies. This imaging modality complements confocal reflectance adaptive optics scanning light ophthalmoscopy, which relies on the waveguiding properties of cones, as well as their orientation toward the pupil. Split-detection contrast, however, is directional, with each cone inner segment appearing as opposite dark and bright semicircles, presenting a challenge for either manual or automated cell identification. Quadrant-detection imaging, an evolution of split detection, could be used to generate images without directional dependence. Here, we demonstrate how the embossed-filtered quadrant-detection images, originally proposed by Migacz et al. for visualising hyalocytes, can also be used to generate photoreceptor mosaic images with better and non-directional contrast for improved visualisation. As a surrogate of visualisation improvement between legacy split-detection images and the images resulting from the method described herein, we provide preliminary results of simple image processing routines that may enable the automated identification of generic image features, as opposed to complex algorithms developed specifically for photoreceptor identification, in pathological retinas.
非共焦分裂检测成像揭示了在多种视网膜疾病状态下视锥光感受器内节镶嵌结构，有潜力为衰老、疾病及治疗反应过程提供深入见解，并可用于筛选细胞拯救疗法的候选对象。这种成像方式补充了共焦反射自适应光学扫描激光检眼镜，后者依赖于视锥的波导特性及其朝向瞳孔的方向。然而，分裂检测对比度具有方向性，每个视锥内节呈现为相反的暗半圈和亮半圈，这对人工或自动细胞识别都构成挑战。象限检测成像作为分裂检测的一种改进形式，可用于生成无方向依赖性的图像。在此，我们展示了最初由米加茨等人提出的用于可视化玻璃体细胞的浮雕滤波象限检测图像，如何也能用于生成具有更好且无方向对比度的光感受器镶嵌图像，以改善可视化效果。作为传统分裂检测图像与本文所述方法生成的图像之间可视化改进的替代方法，我们提供了简单图像处理程序的初步结果，这些程序可能能够自动识别病理视网膜中一般的图像特征，而非专门为光感受器识别开发的复杂算法。
