Ophthalmic Anatomy PDF

Innervation Choroid Suprachoroidea 79 SECTION I 2: Ophthalmic Anatomy Section I: Basic Vision Sciences SECTION I 80 Figure 2.61 A. B. choroid, where the suprachoroidea (Su) forms fine collagenous attachments (arrows) with lamina fusca of the sclera (S). (Original Large-Vessel Layer Fig...

Innervation Choroid Suprachoroidea 79 SECTION I 2: Ophthalmic Anatomy Section I: Basic Vision Sciences SECTION I 80 Figure 2.61 A. B. choroid, where the suprachoroidea (Su) forms fine collagenous attachments (arrows) with lamina fusca of the sclera (S). (Original Large-Vessel Layer Figure 2.62 SEM corrosion cast of the choroidal vasculature in the dog. Large arrows indicate collateralization of the intrascleral indicate choroidal arteries. (Original magnification, 10×.) 81 SECTION I 2: Ophthalmic Anatomy Figure 2.64 The outer choroid in the avian (i.e., chicken) eye consists of sinusoids (S) that extend to the suprachoroidea (Original magnification, 200×.) Figure 2.63 SEM of the posterior canine eye shows the choroid choriocapillaris (arrow), which nourishes the outer retina (R). S, Section I: Basic Vision Sciences SECTION I 82 Figure 2.65 The tapetum lucidum (T), which is always located dorsally, usually ends along the horizontal plane next to or the retina and choroid (*) have been removed to demonstrate the posterior eyewall, the sclera (S). Feline globe. Figure 2.66 The carnivorous tapetum lucidum (TL) consists of layers of cells, called iridocytes, which vary in number, size, and composition. A. The dog. B. The cat. (Original magnification: 200×.) 2: Ophthalmic Anatomy Choroidal tapeta among selected vertebrates. Classification Type of tapetum Reflective material Figure 2.67 Tapetal cells of a cat. The main cytoplasmic are uniform in a group concerning spatial orientation, but more than one group is often present within a cell (arrows). The sides of adjacent cells have wide intercellular spaces with scattered collagen Thickness Size of fibrils or rodlet dimensions SECTION I Table 2.10 83 Section I: Basic Vision Sciences SECTION I 84 Choriocapillaris Figure 2.68 sized blood vessels with the choriocapillaris (CC) in the cat. The iridocytes (I), or tapetal cells, line up evenly next to 7200×.) Figure 2.69 Choriocapillaris in the dog. A. B. The (Original magnification, 3000×.) 2: Ophthalmic Anatomy 85 Animal Volume (mL) Anteroposterior axis (mm) Diameter (mm) Lens Table 2.12 Age Anterior pole ( m) Equator ( m) Lens Capsule Anterior Epithelium Posterior pole ( m) SECTION I Table 2.11 Section I: Basic Vision Sciences SECTION I 86 Lens Fibers Figure 2.71 The anterior epithelium of a neonatal canine lens near the equator (E) has a proliferative zone at which cells undergo mitosis (arrows) and, subsequently, are pushed toward the equator. (Original magnification, 400×.) Figure 2.70 Composite drawing of the lens, capsule, attachments, and nuclear zones. The lens epithelial cells line the anterior capsule. At the equator, these dividing cells elongate to form lens cortical cells (fibers). As they elongate anteriorly and posteriorly toward the sutures, their nuclei migrate somewhat anterior to the equator and form the lens bow. Zonular fibers (zf) attach to the anterior and posterior lens capsule and to the equatorial capsule, forming pericapsular or zonular lamellae of the lens. (Source: Modified from Hogan, M.J., Alvarado, J.A. & Histology of the Human Eye