This educational image displays the normal anatomy of the human retina and macula through diagnostic imaging and anatomical diagrams. Panel (a) is a high-resolution optical coherence tomography (OCT) cross-section of a normal retina, with detailed labels identifying 12 distinct layers: Nerve Fiber Layer (NFL), Ganglion Cell Layer (GCL), Inner Plexiform Layer (IPL), Inner Nuclear Layer (INL), Outer Plexiform Layer (OPL), Outer Nuclear Layer (ONL), External Limiting Membrane (ELM), various segments of the Photoreceptors, RPE Interdigitation, RPE/Bruch's Membrane Complex, and the underlying Choroid. A characteristic central foveal depression is clearly visible. Panel (b) provides a composite of a clinical fundus photograph and a matching cross-sectional anatomical diagram illustrating macular regional division. The macula is subdivided into concentric zones with specific diameters: the foveola (0.35 mm), fovea (1.5 mm), parafovea (an additional 0.5 mm ring), and perifovea (an additional 1.5 mm ring). The content is designed for medical education in ophthalmology, specifically for understanding normal fundus morphology and interpreting OCT scans for diagnostic purposes.

This diagnostic image is an Optical Coherence Tomography (OCT) cross-section of a human retina, specifically illustrating the anatomical subdivisions of the macula. The image features a normal retinal profile with a characteristic central thinning at the foveal depression. Two red horizontal lines delineate the upper boundary, the Inner Limiting Membrane (ILM), and the lower boundary, the Retinal Pigment Epithelium (RPE). Green vertical lines subdivide the macular region into clinical zones: the central foveola (marked with a white indicator at its center), the fovea, the flanking parafovea (PA_L and PA_R), and the outer perifovea (PE_L and PE_R). The visualization demonstrates the relative thickness variations across these regions, where the inner retinal layers are displaced laterally at the fovea to allow light to reach the photoreceptors directly. This schematic is primarily used in ophthalmology to establish a reference model for identifying morphological abnormalities, such as drusen, epiretinal membranes, or macular edema, by quantifying layer thickness and curvature within specific macular zones.

This diagnostic comparison presents two vertical optical coherence tomography (OCT) B-scans of a human retina, demonstrating the progression and resolution of macular edema secondary to branch retinal vein occlusion (BRVO). Panel A (Initial Visit) shows a cross-section of the fovea with significant intraretinal fluid (IRF) manifesting as large, hyporeflective cystic spaces. This accumulation results in marked retinal thickening and the loss of normal foveal contour, classified as 'one-side IRF' as the fluid is predominantly localized to one side of the foveola. Panel B (12-Month Follow-up) illustrates the post-treatment state, showing complete resolution of the intraretinal fluid and restoration of a more anatomical retinal thickness and profile. A yellow arrow highlights the intact and continuous ellipsoid zone (EZ) band, signifying the preservation of photoreceptor integrity. White arrows in the upper right corners indicate the vertical scan orientation. These images serve as an educational example of treatment efficacy and the importance of monitoring outer retinal layers, such as the EZ band, for visual prognosis in vascular retinal diseases.

A comparison graphic of human ocular anatomy featuring an anatomical diagram alongside a high-resolution Spectral Domain Optical Coherence Tomography (SD-OCT) cross-section of the fovea and posterior segment. The image serves as an educational tool for ophthalmology, specifically identifying the microstructural layers of the retina and choroid. Starting from the inner retina and moving outward toward the sclera, the labeled structures include the foveal pit, retinal pigment epithelium (RPE), Bruch's membrane, and the subsequent choroidal layers: choriocapillaris, Sattler layer (small-to-medium vessels), Haller layer (large vessels), virtual suprachoroidal space, and Lamina fusca. The OCT image illustrates these as hyperreflective and hyporeflective bands, with the RPE appearing as a prominent bright band. This visual highlights the clinical methodology for measuring choroidal thickness, defined as the distance between the RPE-choroid interface and the sclerochoroidal interface. The image is designed for advanced medical education in diagnostic imaging and retinal pathology.