Sun Lynn W, Johnson Ryan D, Langlo Christopher S, Cooper Robert F, Razeen Moataz M, Russillo Madia C, Dubra Alfredo, Connor Thomas B, Han Dennis P, Pennesi Mark E, Kay Christine N, Weinberg David V, Stepien Kimberly E, Carroll Joseph
Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States.
Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States.
Invest Ophthalmol Vis Sci. 2016 May 1;57(6):2428-42. doi: 10.1167/iovs.15-18246.
The purpose of this study was to examine cone photoreceptor structure in retinitis pigmentosa (RP) and Usher syndrome using confocal and nonconfocal split-detector adaptive optics scanning light ophthalmoscopy (AOSLO).
Nineteen subjects (11 RP, 8 Usher syndrome) underwent ophthalmic and genetic testing, spectral-domain optical coherence tomography (SD-OCT), and AOSLO imaging. Split-detector images obtained in 11 subjects (7 RP, 4 Usher syndrome) were used to assess remnant cone structure in areas of altered cone reflectivity on confocal AOSLO.
Despite normal interdigitation zone and ellipsoid zone appearance on OCT, foveal and parafoveal cone densities derived from confocal AOSLO images were significantly lower in Usher syndrome compared with RP. This was due in large part to an increased prevalence of non-waveguiding cones in the Usher syndrome retina. Although significantly correlated to best-corrected visual acuity and foveal sensitivity, cone density can decrease by nearly 38% before visual acuity becomes abnormal. Aberrantly waveguiding cones were noted within the transition zone of all eyes and corresponded to intact inner segment structures. These remnant cones decreased in density and increased in diameter across the transition zone and disappeared with external limiting membrane collapse.
Foveal cone density can be decreased in RP and Usher syndrome before visible changes on OCT or a decline in visual function. Thus, AOSLO imaging may allow more sensitive monitoring of disease than current methods. However, confocal AOSLO is limited by dependence on cone waveguiding, whereas split-detector AOSLO offers unambiguous and quantifiable visualization of remnant cone inner segment structure. Confocal and split-detector thus offer complementary insights into retinal pathology.
本研究旨在使用共聚焦和非共聚焦分裂探测器自适应光学扫描激光眼科显微镜（AOSLO）检查视网膜色素变性（RP）和Usher综合征患者的视锥光感受器结构。
19名受试者（11例RP，8例Usher综合征）接受了眼科和基因检测、光谱域光学相干断层扫描（SD-OCT）以及AOSLO成像。对11名受试者（7例RP，4例Usher综合征）获得的分裂探测器图像用于评估共聚焦AOSLO上视锥反射率改变区域的残余视锥结构。
尽管OCT上的指状交叉区和椭圆体区外观正常，但与RP相比，Usher综合征患者共聚焦AOSLO图像得出的中央凹和中央凹旁视锥密度显著降低。这在很大程度上是由于Usher综合征视网膜中非波导视锥的患病率增加。尽管视锥密度与最佳矫正视力和中央凹敏感度显著相关，但在视力变得异常之前，视锥密度可降低近38%。在所有眼睛的过渡区内均发现异常波导视锥，且与完整的内节结构相对应。这些残余视锥在过渡区内密度降低、直径增加，并随着外界限制膜塌陷而消失。
在OCT上出现可见变化或视功能下降之前，RP和Usher综合征患者的中央凹视锥密度可能已经降低。因此，AOSLO成像可能比现有方法能更敏感地监测疾病。然而，共聚焦AOSLO受视锥波导依赖性的限制，而分裂探测器AOSLO能提供残余视锥内节结构的清晰且可量化的可视化。因此，共聚焦和分裂探测器为视网膜病理学提供了互补的见解。
