Faculty Bibliography

PURPOSE/OBJECTIVE:To introduce a simple method for differentiating retinal veins from arteries on optical coherence tomography angiography (OCTA). DESIGN/METHODS:Cross-sectional pilot study. METHODS:Four default en face slabs including color depth encoded, greyscale full-thickness retina, superficial plexus, and deep capillary plexus (DCP) from 9 3x3 mm and 9 6x6 mm OCTA scans were exported and aligned. Nine ophthalmologists with minimum OCTA experience from 2 eye institutions were instructed to classify labeled vessels as arteries or veins in 3 stages. Classification was performed based on graders' own assessment at Stage 1. Graders were taught that a capillary-free zone was an anatomic feature of arteries at Stage 2 and were trained to identify veins originating from vortices within the DCP at Stage 3. Grading accuracy was analyzed and correlated with grading time and graders' years in practice. RESULTS:Overall grading accuracy in Stages 1, 2, and 3 was (50.4 ± 17.0) %, (75.4 ± 6.0) %, and (94.7 ± 2.6) %, respectively. Grading accuracy for 3x3 mm scans in Stages 1, 2, and 3 was (49.9 ± 16.3) %, (79.2 ± 9.6) %, and (96.9 ± 3.1) %, respectively. Accuracy for 6x6 mm scans in Stages 1, 2, and 3 was (51.4 ± 20.8) %, (72.3 ± 7.9) %, and (93.2 ± 3.3) %, respectively. Grading performance improved significantly at each stage (all P < .001). No significant correlation was found between accuracy and time spent grading or between accuracy and years in practice (r = -0.164 - 0.617, all P ≥ 0.077). CONCLUSIONS:We describe a simple method for accurately distinguishing retinal arteries from veins on OCTA which incorporates the use vortices in the DCP to identify venous origin.

BACKGROUND AND OBJECTIVE/OBJECTIVE:To describe the multimodal imaging characteristics associated with punctate outer retinal toxoplasmosis (PORT). PATIENTS AND METHODS/METHODS:Multicenter, retrospective, observational case series of three patients who presented with PORT. Multimodal imaging was reviewed including optical coherence tomography (OCT), fundus autofluorescence, optical coherence tomography angiography, and conventional dye-based angiography. RESULTS:Patient ages ranged from 13 years to 55 years. Each patient had multiple white, punctate outer retinal lesions in the affected eye at initial diagnosis. OCT showed both inner and outer retinal changes, including disruption of the ellipsoid and interdigitation zones and retinal pigment epithelium/Bruch's membrane complex, as well as punctate, preretinal, hyperreflective lesions at the vitreoretinal interface, which regressed with treatment. CONCLUSION/CONCLUSIONS:Multimodal imaging is useful in diagnosing and monitoring treatment response in PORT, an uncommon presentation of ocular toxoplasmosis that must be differentiated from white dot syndromes or other causes of unilateral retinitis. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:281-287.].

PURPOSE/OBJECTIVE:To correlate multimodal retinal imaging with high-resolution epoxy resin histologic analysis aligned to in vivo tomograms in a patient with exudative aneurysmal type 1 (AT1) neovascularization and hemorrhage secondary to age-related macular degeneration (AMD). DESIGN/METHODS:Case study and clinicopathologic correlation. PARTICIPANT/METHODS:An 84-year-old man of European descent with AT1 neovascularization secondary to AMD with a 6-year follow-up with combined antiangiogenic and photodynamic therapy. METHODS:Multimodal imaging from each clinic visit, including fluorescein angiography, indocyanine green angiography, and OCT, was correlated with ex vivo OCT and high-resolution histologic images of the donor eye, aligned to the en face images showing hemorrhage and exudation. MAIN OUTCOME MEASURES/METHODS:Location of the branching vascular network and the aneurysmal vascular dilations in angiography, correlated with histologic findings. RESULTS:Clinically, a hemorrhagic detachment of the retinal pigment epithelium (RPE) in the macular area was associated with an AT1 neovascularization extending near the optic nerve head, where the choroid, which was thin overall, was extremely thin. Resolution of the hemorrhage accompanied by progressive macular atrophy and internal changes in the reflectivity of the RPE detachment were observed. Histologic analysis suggested a physical continuity from a hyalinized choroidal artery to a capillary bed (branching vascular network) in the sub-RPE-basal lamina (BL) space without visualization of aneurysmal dilations. CONCLUSIONS:Clinicopathologic correlation of AT1 neovascularization from an intact treated eye with dye-based angiographic and OCT scans supports the proposed nomenclature of AT1 neovascularization over polypoidal choroidal vasculopathy. We described continuity of the sub-RPE-BL branching vascular network with choroidal arteries and histologic correlates of common OCT signatures of neovascular AMD. The thinness of choroid in this patient of European descent contrasts with that reported for Asian populations, in which AT1 neovascularization is associated commonly with pachychoroid disease characteristics. This case reinforces the different manifestations of AT1 neovascularization across and within diverse ethnicities and diseases.

The authors report a case of nonconforming focal choroidal excavation (FCE) identified in an eye following blunt, nonperforating trauma to the globe. Multimodal imaging was undertaken including color fundus photographs, enhanced depth imaging optical coherence tomography, fluorescein angiography, and fundus autofluorescence. This shows that FCE may result from blunt ocular trauma. The authors hypothesize that loss of structural support provided by an intact Bruch's membrane may be a key factor in precipitating the specific morphological changes associated with FCE occurring in a range of clinical settings. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:187-190.].

PURPOSE/OBJECTIVE:In an eye with geographic atrophy (GA) secondary to age-related macular degeneration, we correlated ex vivo histologic features with findings recorded in vivo using optical coherence tomography (OCT), near-infrared reflectance imaging, and fundus autofluorescence. METHODS:In the left eye of an 86-year-old white woman, in vivo near-infrared reflectance and eye-tracked OCT B-scans at each of 6 clinic visits and a baseline fundus autofluorescence image were correlated with ex vivo - high-resolution histologic images of the preserved donor eye. RESULTS:Clinical imaging showed a small parafoveal multilobular area of GA, subfoveal soft drusen, refractile drusen, hyperreflective lines near the Bruch membrane, subretinal drusenoid deposit (reticular pseudodrusen), and absence of hyperautofluorescent foci at the GA margin. By histology, soft drusen end-stages included avascular fibrosis with highly reflective cholesterol crystals. These accounted for hyperreflective lines near the Bruch membrane in OCT and plaques in near-infrared reflectance imaging. Subretinal drusenoid deposit was thick, continuous, extracellular, extensive outside the fovea, and associated with distinctive retinal pigment epithelium dysmorphia and photoreceptor degeneration. A hyporeflective wedge corresponded to ordered Henle fibers without cellular infiltration. The external limiting membrane descent, which delimits GA, was best visualized in high-quality OCT B-scans. Retinal pigment epithelium and photoreceptor changes at the external limiting membrane descent were consistent with our recent histologic survey of donor eyes. CONCLUSION/CONCLUSIONS:This case informs on the extent, topography, and lifecycle of extracellular deposits. High-quality OCT scans are required to reveal all tissue features relevant to age-related macular degeneration progression to GA, especially the external limiting membrane descent. Histologically validated signatures of structural OCT B-scans can serve as references for other imaging modalities.This is an open access article distributed under the Creative Commons Attribution License 4.0 (CCBY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

BACKGROUND/AIMS/OBJECTIVE:Hydroxychloroquine (HCQ) retinopathy may result in severe and irreversible vision loss, emphasising the importance of screening and early detection. The purpose of this study is to report the novel finding of early optical coherence tomography (OCT) abnormalities due to HCQ toxicity that may develop in the setting of normal Humphrey visual field (HVF) testing. METHODS:Data from patients with chronic HCQ exposure was obtained from seven tertiary care retina centres. Ten patients with HCQ-associated OCT abnormalities and normal HVF testing were identified. Detailed analysis of the OCT findings and ancillary tests including colour fundus photography, fundus autofluorescence, multifocal electroretinography and microperimetry was performed in these patients. RESULTS:Seventeen eyes from 10 patients illustrated abnormalities with OCT and normal HVF testing. These OCT alterations included (1) attenuation of the parafoveal ellipsoid zone and (2) loss of a clear continuous interdigitation zone. Several eyes progressed to advanced parafoveal outer retinal disruption and/or paracentral visual field defects. CONCLUSION/CONCLUSIONS:Patients with high risk HCQ exposure and normal HVF testing may develop subtle but characteristic OCT abnormalities. This novel finding indicates that, in some cases of early HCQ toxicity, structural alterations may precede functional impairment. It is therefore important to employ a screening approach that includes OCT to assess for these early findings. Ancillary testing should be considered in cases with suspicious OCT changes and normal HVFs.