Search

Purpose We evaluate diabetic microaneurysm (MA) features on high-resolution adaptive optics scanning laser ophthalmoscopy (AOSLO) and their correlations with visual acuity (VA) and local retinal pathology on spectral domain optical coherence tomography (SDOCT). Methods Diabetic participants underwent VA testing and AOSLO and SDOCT imaging of MAs. AOSLO images were graded for MA dimension, wall hyperreflectivity (WH), intraluminal hyperreflectivity (IH), and perfusion pattern. SDOCTs centered on each MA were graded for disorganization of the retinal inner layers (DRIL) and other neuroretinal pathology. Results We imaged 109 MAs (30 eyes). Multivariate modeling, including statistically significant covariates from bivariate analyses, associated WH with greater MA size (P = 0.001) and DRIL (P = 0.04). IH was associated with perfusion (P = 0.003) and MA visibility on photographs (P = 0.0001), and larger MA size with partial perfusion (P = 0.03), MA ring signs (P = 0.0002), and photographic visibility (P = 0.01). Multivariate modeling revealed an association of WH and VA with DRIL. Conclusions AOSLO imaging demonstrates associations of hyperreflective MA walls with MA size and adjacent DRIL, as well as the presence of DRIL with lower VA. This study identifies a correlation between vascular and neural pathology associated with VA decline. Further studies of MA structure and neuroretinal disorganization may enable novel approaches to assess anatomic and functional outcomes in the diabetic eye.

Purpose 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). Methods 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. Results 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. Conclusions 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.