No abstract

No abstract

Purpose: To determine factors that may affect the repeatability of the foveal avascular zone (FAZ) measurement obtained using optical coherence tomography angiography (OCTA) including instrument type, image segmentation, image quality, and fundus pathology. Patients and Methods: This prospective single-center study enrolled 43 subjects (85 eyes) with retinal vasculopathy, macular edema, optic pathology or normal contralateral eye. The macula was imaged twice using Optovue Angiovue and once using Cirrus Angioplex to obtain 3x3mm OCTA images centered on the fovea. Images were generated by the same operator within 30 mins. The FAZ size for the entire retinal thickness ("overall FAZ") was measured automatically using the OCTA software. The FAZ size of the superficial and deep retinal vascular plexus layers was measured manually using the enface OCTA images of the segmented layers and Image J analysis. Intraclass correlations coefficient (ICC) was calculated to determine repeatability. Results: For the overall FAZ measurement, repeatability was excellent (ICC 0.953 right eye, 0.938, left eye) using the same machine (intra-instrument) and somewhat lower but still good to excellent (ICC 0.803 right eye, 0.917 left eye) using machines made by different vendors (inter-instrument). For the segmented layers, intra-instrument repeatability of FAZ measurement was excellent (ICC > 0.95) for both plexus layers. Inter-instrument repeatability was good for the superficial plexus layer (ICC 0.86 right eye, 0.88 left eye) but reduced for the deep plexus layer (ICC 0.63 right eye, 0.57 left eye). Suboptimal image quality and presence of retinal vasculopathy and macular edema tended to reduce FAZ repeatability but to a lesser degree. Conclusion: Inter-and intra-instrument repeatability of the overall FAZ measurement was high using commercial OCTA instruments and only mildly reduced by suboptimal image quality and fundus pathology. For segmented layers, intra-instrument repeatability remained high but inter-instrument repeatability was reduced for the deep plexus layer.

BACKGROUND AND OBJECTIVE: To determine if age-related macular degeneration (AMD) status affects longitudinal retinal vessel changes. PATIENTS AND METHODS: Retrospective, cohort study of 125 eyes (75 patients) with AMD, following retinal vessel density (VD) and foveal avascular zone (FAZ) measurements using optical coherence tomography angiography (OCT-A) over 24 months. RESULTS: FAZ area ( P < .001) and perimeter ( P < .001) increased over 2 years, with no difference between nonexudative and exudative AMD ( P = .134–.976). Eyes with geographic atrophy (GA) showed greater progressive VD loss ( P = .023–.038), and greater increase in FAZ area ( P = .044) and perimeter ( P = .040) compared to eyes without GA. Neither baseline nor 2-year change in vascular parameters were associated with choroidal neovascularization (CNV) or GA incidence in nonexudative AMD, or anti-VEGF injection frequency in exudative AMD ( P = .070–.952). CONCLUSION: AMD eyes with GA undergo more rapid loss of retinal vessel density and FAZ enlargement over 2 years, suggesting a relationship between the retinal vasculature and AMD pathophysiology. [ Ophthalmic Surg Lasers Imaging Retina 2022;53:529–536.]

Vascular endothelial growth factors (VEGFs) are key mediator of retinal and choroidal neovascularization as well as retinal vascular leakage leading to macular edema. As such, VEGF plays an important role in mediating visually significant complications associated with common retinal disorders such as diabetic retinopathy, retinal vein occlusion, and age-related macular degeneration. Various drugs that inhibit vascular endothelial growth factors (anti-VEGF therapies) have been developed to minimize vision loss associated with these disorders. These drugs are injected into the vitreous cavity in a clinic setting at regular intervals. This article provides an overview of the various anti-VEGF drugs used in ophthalmology and the common retinal conditions that benefit from this therapy.