Vascular layer of the eye

A brief presentation on the topic "vascular layer of the eye"

1. VASCULAR TUNIC - RAJA MD

2. EYE FIBROUS TUNIC VASCULAR TUNIC NERVOUS TUNIC It’s the middle coat of eye and its also known as Uvea Vascular and pigmented FUNCTIONS Regulates light entry Anchors the Lens Nourishes Retina COMPONENTS Choroid Ciliary Body Iris

3. CHOROID A lso known as the Choroidea or   Choroid   coat Thin, highly pigmented, Areolar connective tissue . Forms the  Uveal Tract along with the  Ciliary Body  and  Iris. P rovides   oxygen   & nourishment to the outer layers of   retina. Thickness decreases from posterior to anterior. Rich in Melanocytes gives characteristic dark color Pigment absorbs extraneous light LAYERS OF CHOROID There are 5 Layers of choroid; Suprachoroidal lamina - transition zone of sclera and choroid. vascular layers - ( Haller's and Sattler's) Choroidal stroma - layer of pigmented, vascularized loose connective tissues choriocapillaris  - layer of rich capillaries network Bruch's membrane  - innermost layer of the choroid

4. CILIARY BODY is a circular structure that is present in the end of choroid, connection it to the circumference of iris FUNCTIONS Production of Aqueous humor Control visual accommodation PARS PLICATA The folded & most anterior portion of the ciliary body located anterior to the pars plana & posterior to the iris. Contain ciliary process, which extend into the posterior chamber Has Lens Zonules  that are used to control lens for visual   accommodation

5. PARS PLANA Also known as Orbicularis ciliaris located near the junction of the iris and sclera, and is scalloped in appearance CILIARY MUSCLES make up most of ciliary body stroma Contraction of these muscles affects the shape of the lens and is important in visual accommodation 3 groups of smooth muscle fibers :- Longitudinal Muscles (outermost ) Radial Muscle Circular Muscle (innermost) CILIARY STROMA Highly vascularized loose connective tissue Anteriorly continuous with iris stroma Posteriorly continuous with choroidal stroma Thin in pars plana

6. CILIARY PROCESSES  70-80 finger-like projections radiating from pars plicata Each process is about 2mm long and 0.5mm in diameter Occupy peripheral part of posterior chamber Grooves in between serve as attachment for lens zonules FUNCTION  P roduction of   Aqueous Humor , Fluid from the stromal microvasculature moves across the ciliary epithelium as aqueous humor , with an inorganic ion composition similar to that of plasma but almost no protein

7. Aqueous humor is secreted by ciliary processes into the posterior chamber , flows through the pupil into the anterior chamber , and drains at the angle formed by the cornea and the iris into the channels of the Trabecular Meshwork and the Scleral Venous Sinus , from which it enters venules of the sclera. SECRETION OF AQUEOUS HUMOR CILIARY EPITHELIUM 2 layers of cells:- PIGMENTED EPITHELIUM ( outer – next to stroma) Anterior part continuous with anterior iris epithelium NON-PIGMENTED EPITHELIUM (inner – faces posterior chamber) Produces aqueous humor & glycoprotein of vitreous humor.

8. CILIARY ZONULE S eries of fibers connecting the  ciliary   body and Lens The fibers extend from grooves between the ciliary processes Attach to the surface of the lens composed largely of fibrillin-1 and 2 produced by the nonpigmented epithelial cells on the ciliary processes. IRIS M ost anterior extension of the middle uveal layer H ole located in the center of the iris is Pupil, allows light to strike the retina. The free edge is known as Pupillary margin Separates the chambers which are continuous through pupil  Stroma of iris is continuous with stroma of ciliary body Muscles :- Pupillary sphincter muscle Pupillary dilator muscle

9. LAYERS OF IRIS 4 layers of iris :- Anterior limiting layer Thin, discontinuous & Composed of Collagen Fibrils , Fibroblasts & Melanocytes Stroma & sphincter muscle layer Loose , pigmented & highly vascular connective tissue Pigmented epithelium lining the posterior surface Composed of collagen fibrils & extensive ground substance Amount of melanocytes in stroma determines eye color Sphincter muscle :- lies in stroma, near pupil, concentrically arranged, contraction causes pupil constriction Innervated by oculomotor , parasympathetic nervous system

10. Anterior epithelium & dilator muscle layer Composed of unique myoepithelial cells Dilator muscle :- Smooth muscle that extends into stroma forming 4-5 layers Radially arranged, Contraction causes pupil dilatation & innervated by sympathetic nervous system Posterior epithelium Single layer of heavily pigmented simple columnar cells At posterior, continuous with inner non- pigmented epithelial layer of ciliary body Curled to anterior surface at pupil margin – Pupillary ruff

11. THANK YOU