MULTISCALE CORRELATION OF MICROVASCULAR CHANGES ON OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY WITH RETINAL SENSITIVITY IN DIABETIC RETINOPATHY.

PURPOSE: To assess global, zonal, and local correlations between vessel density changes measured by optical coherence tomography angiography and retinal sensitivity measured by microperimetry across diabetic retinopathy severity. METHODS: Diabetic patients and nondiabetic controls underwent optical coherence tomography angiography imaging and microperimetry testing. Pearson's correlation was used to assess associations between average sensitivity and skeletonized vessel density (SVD) or foveal avascular zone area centrally. Linear mixed effects modeling was used to assess relationships between local SVD measurements and their spatially corresponding retinal sensitivity measurements. RESULTS: Thirty-nine eyes from 39 participants were imaged. In all slabs, there was a statistically significant positive correlation between retinal sensitivities and SVDs on both global and zonal scales. No statistically significant correlation was found between central retinal sensitivities and the foveal avascular zone areas. Assessment of 1,136 spatially paired retinal sensitivity and SVD measurements revealed a statistically significant local relationship; this seemed to be driven by eyes with proliferative diabetic retinopathy that had reduced retinal sensitivities. CONCLUSION: This study supports positive correlations between SVD and retinal sensitivity at global and zonal spatial scales in diabetic eyes. However, our analysis did not find evidence of statistically significant correlations between retinal sensitivity and SVD on a local scale until advanced diabetic retinopathy.

LONG-TERM VISUAL RECOVERY IN BILATERAL HANDHELD LASER POINTER-INDUCED MACULOPATHY.

PURPOSE: To describe the long-term visual, clinical, and optical coherence tomography (OCT) recovery after 4 years in a patient who incurred severe bilateral handheld laser pointer damage. METHODS: The findings on clinical examination, color fundus photography, and spectral domain OCT at presentation followed by sequential time points over 4 years are presented. RESULTS: A 9-year-old healthy boy presented with bilateral reduced vision to count fingers in each eye with yellow irregular lesions. After extensive evaluation, he admitted to multiple, prolonged episodes of staring at a handheld red laser pointer reflected in a mirror. Initial visual acuity was count fingers bilaterally. Clinical examination revealed bilateral yellow streaks radiating from the fovea without hemorrhages or fluid and retinal pigment epithelium pigmentary mottling. Spectral domain OCT showed disruption of the foveal outer retina extending from the outer plexiform layer to the retinal pigment epithelium spanning 896 µm in the right eye and 564 µm in the left eye. Six months after injury, vision had only minimally improved to 20/200 with resolution of outer plexiform layer and outer nuclear layer opacification on OCT. Over the ensuing 4 years, visual acuity slowly recovered to 20/30 in each eye and the regions of outer retinal disruption progressively reduced in size to 295 µm in the right eye and 115 µm in the left eye. CONCLUSION: This case illustrates gradual vision and anatomical improvement over 4 years despite initial poor vision after severe laser pointer macular damage. Visual recovery may be related to patient and exposure factors as well as initial OCT features where an intact Bruch membrane can provide a scaffold for photoreceptors to recover, thereby reducing the outer retinal defect.

SPATIAL DISTRIBUTION OF CHORIOCAPILLARIS IMPAIRMENT IN EYES WITH CHOROIDAL NEOVASCULARIZATION SECONDARY TO AGE-RELATED MACULAR DEGENERATION: A Quantitative OCT Angiography Study.

PURPOSE: To develop an optical coherence tomography angiography (OCTA)-based framework for quantitatively analyzing the spatial distribution of choriocapillaris (CC) impairment around choroidal neovascularization (CNV) secondary to age-related macular degeneration. METHODS: In a retrospective, cross-sectional study, 400-kHz swept-source OCTA images from 7 eyes of 6 patients with CNV secondary to age-related macular degeneration were quantitatively analyzed using custom software. A lesion-centered zonal OCTA analysis technique-which portioned the field-of-view into zones relative to CNV boundaries-was developed to quantify the spatial dependence of CC flow deficits. RESULTS: Quantitative, lesion-centered zonal analysis of CC OCTA images revealed highest flow-deficit percentages near CNV boundaries, decreasing in zones farther from the boundaries. Optical coherence tomography angiography using shorter (1.5 ms) interscan times revealed more severe flow deficits than OCTA using longer (3.0 ms) interscan times; however, spatial trends were similar for both interscan times. A detailed description of the OCTA processing steps and parameters was provided so as to elucidate their influence on quantitative measurements. CONCLUSION: Impairment of the CC, assessed by flow-deficit percentages, was most prominent closest to CNV boundaries. The lesion-centered zonal analysis technique enabled quantitative CC measurements relative to focal lesions. Understanding how processing steps, imaging/processing parameters, and artifacts can affect quantitative CC measurements is important for longitudinal, OCTA-based studies of disease progression, and treatment response.

Vascularized drusen: a cross-sectional study.

BACKGROUND: To investigate whether neovascularization may arise and be detectable in drusen, as reported in histopathologic studies, by OCTA prior to developing exudation and to assess its prevalence in a cohort of patients with intermediate AMD. METHODS: Retrospective cross-sectional study of 128 patients with intermediate AMD recruited as part of a separate ongoing clinical trial conducted at multiple large tertiary referral retina clinics. One hundred and twenty-eight consecutive patients with exudative AMD in one eye and intermediate non-exudative AMD in the fellow eye were enrolled and analyzed between September 2015 and March 2017. RESULTS: SD-OCTA identified vascularization within drusen in 7 of 128 eyes, for a prevalence of 5.5%. A total of 12 instances of vascularized drusen were noted. Out of the 12 vascularized drusen noted, 7 were located in the parafoveal region or subfoveal region and 5 was in the extrafoveal region. 9 of 12 instances of vascularized drusen exhibited a uniform sub-RPE hyperreflectivity, whilst 3 of 12 exhibited more heterogenous reflectivity. In all 12 instances, FA images failed to identify the neovascular nature of vascularized drusen. CONCLUSIONS: Our results demonstrate the utility of SD-OCTA for the diagnosis of vascularized drusen in patients with intermediate non-exudative AMD. Longitudinal studies are needed to delineate the evolution and conversion risk of these lesions over time, which can be of substantial clinical relevance.