The eye contains several anatomical structures that work together to allow for vision. The tear film has optical, mechanical, nutritional, and defensive functions and is composed of lipid, aqueous, and mucus layers secreted by various glands. The conjunctiva protects the eye and provides stem cells. The cornea and lens refract light before it reaches the retina. Within the retina are the photoreceptors, bipolar and ganglion cells. Structures like the iris, ciliary body, trabecular meshwork and optic nerve also contribute to vision and pressure regulation.
The document provides an overview of the anatomy of the eyelid. It describes the eyelid's gross anatomy including its extent, folds, margins, lashes and palpebral aperture. It details the layers that make up the eyelid including skin, muscles such as the orbicularis oculi and levator palpebrae superioris, and glands like the meibomian and moll glands. The arterial blood supply and lymphatic and nerve drainage of the eyelid are also summarized.
The cornea develops from surface ectoderm, mesenchyme, and neural crest cells during embryogenesis. It has five layers - epithelium, Bowman's layer, stroma, Descemet's membrane, and endothelium. The stroma comprises the majority of the cornea and contains tightly packed collagen fibrils for strength. The endothelium regulates hydration to maintain corneal transparency. Metabolic processes and the avascular nature of the cornea allow it to remain clear by preventing edema. The cornea refracts light, protects the eye, and contains nerves for sensation.
anatomy and physiology of lacrimal apparatus pptRohit Rao
This document summarizes key aspects of the lacrimal system including its embryology, anatomy, physiology and role in tear formation and drainage. It discusses the lacrimal gland, canaliculi, lacrimal sac, nasolacrimal duct and meibomian glands. It also describes the layers of the tear film - glycocalyx, mucous, aqueous and lipid layers - and their functions in lubricating and protecting the eye. The document is a comprehensive overview of the lacrimal system and tear film.
Cornea is the clear front surface of the eye. It lies directly in front of the iris and pupil, and it allows light to enter the eye.
Cornea forms the transparent and anterior 1/6th of the external fibrous coat of the globe of the eyeball.
The cornea is the eye's most powerful structure for focusing light that provides approximately 65 to 75 percent of the focusing power of the eye.
The cornea has unmyelinated nerve endings sensitive to touch, temperature and chemicals; a touch of the cornea causes an involuntary reflex to close the eyelid.
This document provides an overview of the anatomy of the conjunctiva and sclera. It discusses the embryology, parts, histology, blood supply, nerve supply, and clinical correlations of the conjunctiva. It also reviews the anatomy of the sclera and episclera, as well as inflammation of the sclera and episclera. The document is organized into sections covering the embryology, anatomy, blood supply, nerve supply, and clinical applications of the conjunctiva and sclera.
The cornea is the transparent front part of the eye that refracts light. It is avascular, watch glass-like in structure, and forms the anterior 1/6 of the outer fibrous coat of the eye. The cornea has five layers - epithelium, Bowman's membrane, substantia propria, Dua's layer, and Descemet's membrane - and has an refractive power of +43 to +44 diopters. It receives nourishment from tears and aqueous humour since it lacks blood vessels. The cornea's avascular and dehydrated state, uniform refractive index, and collagen fiber spacing allow it to transmit and focus light while maintaining the globe's structural integrity and protecting the inside of the
The conjunctiva is a vascularized mucous membrane that covers the anterior surface of the eyeball and posterior surface of the eyelids. It combats infection through its vascular and immunological properties. The conjunctiva has three layers - an epithelial layer, substantia propria layer, and goblet cells that secrete mucus. The sclera is the dense outer coat of the eyeball that protects its contents and maintains the globe's shape. It has three layers - episclera, scleral stroma, and lamina fusca. Both structures are supplied by arteries and veins and contain nerves to detect inflammation or eye movement.
Anatomy and physiology of eye, general introduction.arya das
This document summarizes the glands and vasculature of the conjunctiva. There are three main types of glands - mucin secretory glands, accessory lacrimal glands, and goblet cells. The mucin glands include globlet cells, Henle's glands, and glands of Manz. The accessory lacrimal glands include glands of Krause, glands of Wolffring, and rudimentary accessory lacrimal glands. The conjunctiva receives blood supply from the marginal arterial arcade, peripheral arterial arcade, and anterior ciliary arteries. Lymphatic drainage is to the periauricular and submandibular lymph nodes. Nerve supply
The document provides an overview of the anatomy of the eyelid. It describes the eyelid's gross anatomy including its extent, folds, margins, lashes and palpebral aperture. It details the layers that make up the eyelid including skin, muscles such as the orbicularis oculi and levator palpebrae superioris, and glands like the meibomian and moll glands. The arterial blood supply and lymphatic and nerve drainage of the eyelid are also summarized.
The cornea develops from surface ectoderm, mesenchyme, and neural crest cells during embryogenesis. It has five layers - epithelium, Bowman's layer, stroma, Descemet's membrane, and endothelium. The stroma comprises the majority of the cornea and contains tightly packed collagen fibrils for strength. The endothelium regulates hydration to maintain corneal transparency. Metabolic processes and the avascular nature of the cornea allow it to remain clear by preventing edema. The cornea refracts light, protects the eye, and contains nerves for sensation.
anatomy and physiology of lacrimal apparatus pptRohit Rao
This document summarizes key aspects of the lacrimal system including its embryology, anatomy, physiology and role in tear formation and drainage. It discusses the lacrimal gland, canaliculi, lacrimal sac, nasolacrimal duct and meibomian glands. It also describes the layers of the tear film - glycocalyx, mucous, aqueous and lipid layers - and their functions in lubricating and protecting the eye. The document is a comprehensive overview of the lacrimal system and tear film.
Cornea is the clear front surface of the eye. It lies directly in front of the iris and pupil, and it allows light to enter the eye.
Cornea forms the transparent and anterior 1/6th of the external fibrous coat of the globe of the eyeball.
The cornea is the eye's most powerful structure for focusing light that provides approximately 65 to 75 percent of the focusing power of the eye.
The cornea has unmyelinated nerve endings sensitive to touch, temperature and chemicals; a touch of the cornea causes an involuntary reflex to close the eyelid.
This document provides an overview of the anatomy of the conjunctiva and sclera. It discusses the embryology, parts, histology, blood supply, nerve supply, and clinical correlations of the conjunctiva. It also reviews the anatomy of the sclera and episclera, as well as inflammation of the sclera and episclera. The document is organized into sections covering the embryology, anatomy, blood supply, nerve supply, and clinical applications of the conjunctiva and sclera.
The cornea is the transparent front part of the eye that refracts light. It is avascular, watch glass-like in structure, and forms the anterior 1/6 of the outer fibrous coat of the eye. The cornea has five layers - epithelium, Bowman's membrane, substantia propria, Dua's layer, and Descemet's membrane - and has an refractive power of +43 to +44 diopters. It receives nourishment from tears and aqueous humour since it lacks blood vessels. The cornea's avascular and dehydrated state, uniform refractive index, and collagen fiber spacing allow it to transmit and focus light while maintaining the globe's structural integrity and protecting the inside of the
The conjunctiva is a vascularized mucous membrane that covers the anterior surface of the eyeball and posterior surface of the eyelids. It combats infection through its vascular and immunological properties. The conjunctiva has three layers - an epithelial layer, substantia propria layer, and goblet cells that secrete mucus. The sclera is the dense outer coat of the eyeball that protects its contents and maintains the globe's shape. It has three layers - episclera, scleral stroma, and lamina fusca. Both structures are supplied by arteries and veins and contain nerves to detect inflammation or eye movement.
Anatomy and physiology of eye, general introduction.arya das
This document summarizes the glands and vasculature of the conjunctiva. There are three main types of glands - mucin secretory glands, accessory lacrimal glands, and goblet cells. The mucin glands include globlet cells, Henle's glands, and glands of Manz. The accessory lacrimal glands include glands of Krause, glands of Wolffring, and rudimentary accessory lacrimal glands. The conjunctiva receives blood supply from the marginal arterial arcade, peripheral arterial arcade, and anterior ciliary arteries. Lymphatic drainage is to the periauricular and submandibular lymph nodes. Nerve supply
This lecture includes anatomy, Physiology of Sclera, if u like it kindly share it with colleagues and like it. I will share more lectures related to eye anatomy and optometry.
Thank You.
The eyeball has three concentric layers - the outer protective sclera, the middle vascular uvea, and the inner light-sensitive retina. It contains important structures like the cornea, iris, ciliary body, choroid, vitreous humor, and optic nerve. The eye is surrounded by accessory structures including the eyelids, lacrimal apparatus for tear production and drainage, conjunctiva, extraocular muscles to control eye movement, and orbit bone for protection. All of these work together to allow for vision.
The tear film has three layers:
1. A mucin layer secreted by goblet cells that forms a hydrophilic barrier on the cornea.
2. An aqueous layer secreted mainly by the lacrimal gland, containing proteins, electrolytes, and other components.
3. An outer lipid layer secreted by meibomian glands that prevents evaporation and maintains tear film stability.
The tear film is regulated by hormonal and neural pathways and provides nutrients to the cornea, removes waste, lubricates the eye, and protects against infection through its biochemical composition.
The cornea is the transparent front part of the eye that transmits and focuses light. It has 3 main layers - an outer epithelial layer, a thick middle stromal layer made of collagen, and an inner single-cell endothelial layer. The cornea derives its strength and curvature from the orderly arrangement of collagen in the stroma. It remains transparent due to its regular structure without blood vessels and the deturgescent properties maintained by the endothelial pump. The cornea has a high metabolic rate powered by glucose and oxygen and is innervated by nerves for vision and protection.
UVEA constitutes- middle vascular coat
• 3 parts- a)iris
b)ciliary body
c)choroid
• Developmentally,structurally and functionallyindivisible
• color varies from light blue to dark brown
EMBRYOLOGY
IRIS-
• Both layers of epithelium derived from
marginal region of optic cup (neuroectoderm)
• Sphincter and dilator pupillae- anterior
epithelium (neuroectoderm)
• Stroma and vessels- vascular mesoderm
Anatomy of eye and its clinical relevance in Squintdrindeevarmishra
The document discusses the anatomy of the eye and its relevance to squint. It describes the various muscles of the eye including the recti muscles, oblique muscles, and involuntary muscles. It then discusses the gross anatomy including the blood supply and innervation of the eye muscles. It provides details on the tenon's capsule, rectus muscle pulley system, check ligaments, and suspensory ligament of Lockwood. It also describes the surgical anatomy of the inferior oblique, superior oblique, and trochlear components.
The document discusses the anatomy and surgical applications of the limbus. It defines the limbus as the transitional zone between the cornea and sclera, containing the pathways for aqueous humor outflow. Histologically, it describes how the layers of the cornea and conjunctiva become continuous at the limbus. Surgically, it notes the anterior limbal border, blue limbal zone, mid-limbal line, posterior limbal border, and white limbal zone. The best site for cataract incisions is the mid-limbal line, while anterior or posterior incisions risk damage to underlying structures. The limbus contains stem cells that renew the corneal epithelium.
This document provides an overview of the anatomy of the uveal tract, which includes the iris, ciliary body, and choroid. It begins with an introduction and overview of the embryology and development of the uveal tract. It then discusses the anatomy and microstructure of each part of the uveal tract in detail, including their nerve and blood supply. It also briefly discusses some congenital anomalies that can affect the uveal tract.
Eyelids: Different Layer, Nerve Supply, Vascular Supply & Functions of LidsMero Eye
The document describes the anatomy of the eyelids. It discusses the embryology, layers, muscles, glands, nerve and blood supply of the eyelids. The eyelids are derived from surface ectoderm and have multiple layers including skin, muscle, fibrous tissue and conjunctiva. The main muscles are the orbicularis oculi and levator palpebrae superioris. Important glands are meibomian, zeis and moll glands. The eyelids receive motor innervation from cranial nerves and sensory innervation from the trigeminal nerve. Blood supply is from branches of the ophthalmic artery.
The document describes the anatomy and physiology of the lacrimal apparatus. It discusses the following key points:
- The lacrimal apparatus includes the lacrimal gland and associated drainage system for tear production and transport.
- The main structures are the lacrimal gland, puncta, canaliculi, lacrimal sac, and nasolacrimal duct. Tears drain from the puncta through these structures and into the nose.
- The lacrimal gland secretes tears in response to sensory nerve stimulation. Contraction of surrounding muscles aids in drainage and prevents backflow through the puncta.
- Obstruction at any point can cause excess tearing (epiphora) by
The document provides information on the anatomy and embryology of the uvea, which includes the iris, ciliary body, and choroid. It discusses the layers, blood supply, and applied aspects of each structure. The iris is the anterior-most part of the uvea and has sphincter and dilator muscles that control the pupil. The ciliary body lies between the iris and choroid and produces aqueous humor. It contains ciliary processes and muscle. The choroid is the highly vascular posterior layer that nourishes the outer retina. Common conditions like coloboma, aniridia, and heterochromia that involve the uvea are also mentioned.
The retinal anatomy document summarizes the layers and structures of the retina. It notes that the retina consists of 10 distinct layers, including the retinal pigment epithelium, photoreceptor layer, and ganglion cell layer. It describes landmarks such as the macula lutea, fovea centralis, and optic disc. The document also discusses the blood supply to the retina from the central retinal artery and choroidal capillaries, as well as the neuroglial and neurotransmitter components of the retina.
LIMBUS… • The limbus forms the border between the transparent cornea and opaque sclera, contains the pathways of aqueous humour outflow, and is the site of surgical incisions for cataract and glaucoma
2. Anatomical Limbus: Circumcorneal transitional zone of the conjunctivocorneal & corneoscleral junction Conjunctivo-corneal junction: • Bulbar conjunctiva is firmly adherent to underlying structures • Substantia propria of the conjunctiva stops here but its epithelium continues with that of the cornea. Sclero-corneal junction: • Transparent corneal lamellae become continuous • With the oblique, circular and opaque fibres of sclera
3. CONTINUE…. • In the area near limbus, the conjunctiva, tenon’s capsule & the episcleral tissue are fused into a dense tissue which is strongly adherent to corneo scleral junction.It is preferred site for obtaining a firm hold of the eyeball during ocular surgery. • The limbus is a common site for the occurrence of corneal epithelial neoplasm. • The Limbus contains radially oriented fibrovascular ridge known as the palisades of Vogt that may harbour a stem cell population. The palisades of Vogt are more common in the superior and inferior quadrants around the eye
This document describes the anatomy of the extraocular muscles and accessory organs of the eye. It discusses the six extrinsic muscles that control eye movement, including the four rectus and two oblique muscles. It also describes the eyelids, eyelashes, lacrimal apparatus, and other protective structures around the eye. The document provides detailed information on the layers of the eyelids and functions of the tears, lacrimal glands, and associated drainage system.
The cornea is the transparent front part of the eye that allows light to enter. It has six layers - epithelium, Bowman's membrane, stroma, Dua's layer, Descemet's membrane, and endothelium. The stroma makes up most of the thickness and contains collagen fibers. The endothelium maintains corneal hydration through a sodium-potassium pump. The cornea acts as a refracting surface and protects the inside of the eye. It receives nutrients and oxygen from the aqueous humor and perilimbal blood vessels to remain transparent.
The document discusses the anatomy, development and physiology of the lacrimal secretory and drainage systems. It describes the embryological development of the lacrimal system from ectodermal tissue. It details the anatomy of the lacrimal gland, puncta, canaliculi, sac, duct and nasolacrimal drainage system. It explains the physiology of tear secretion, composition of the tear film layers, and the role of nerves, blood vessels and muscles in lacrimal secretion and drainage.
This lecture includes anatomy, Physiology of Sclera, if u like it kindly share it with colleagues and like it. I will share more lectures related to eye anatomy and optometry.
Thank You.
The eyeball has three concentric layers - the outer protective sclera, the middle vascular uvea, and the inner light-sensitive retina. It contains important structures like the cornea, iris, ciliary body, choroid, vitreous humor, and optic nerve. The eye is surrounded by accessory structures including the eyelids, lacrimal apparatus for tear production and drainage, conjunctiva, extraocular muscles to control eye movement, and orbit bone for protection. All of these work together to allow for vision.
The tear film has three layers:
1. A mucin layer secreted by goblet cells that forms a hydrophilic barrier on the cornea.
2. An aqueous layer secreted mainly by the lacrimal gland, containing proteins, electrolytes, and other components.
3. An outer lipid layer secreted by meibomian glands that prevents evaporation and maintains tear film stability.
The tear film is regulated by hormonal and neural pathways and provides nutrients to the cornea, removes waste, lubricates the eye, and protects against infection through its biochemical composition.
The cornea is the transparent front part of the eye that transmits and focuses light. It has 3 main layers - an outer epithelial layer, a thick middle stromal layer made of collagen, and an inner single-cell endothelial layer. The cornea derives its strength and curvature from the orderly arrangement of collagen in the stroma. It remains transparent due to its regular structure without blood vessels and the deturgescent properties maintained by the endothelial pump. The cornea has a high metabolic rate powered by glucose and oxygen and is innervated by nerves for vision and protection.
UVEA constitutes- middle vascular coat
• 3 parts- a)iris
b)ciliary body
c)choroid
• Developmentally,structurally and functionallyindivisible
• color varies from light blue to dark brown
EMBRYOLOGY
IRIS-
• Both layers of epithelium derived from
marginal region of optic cup (neuroectoderm)
• Sphincter and dilator pupillae- anterior
epithelium (neuroectoderm)
• Stroma and vessels- vascular mesoderm
Anatomy of eye and its clinical relevance in Squintdrindeevarmishra
The document discusses the anatomy of the eye and its relevance to squint. It describes the various muscles of the eye including the recti muscles, oblique muscles, and involuntary muscles. It then discusses the gross anatomy including the blood supply and innervation of the eye muscles. It provides details on the tenon's capsule, rectus muscle pulley system, check ligaments, and suspensory ligament of Lockwood. It also describes the surgical anatomy of the inferior oblique, superior oblique, and trochlear components.
The document discusses the anatomy and surgical applications of the limbus. It defines the limbus as the transitional zone between the cornea and sclera, containing the pathways for aqueous humor outflow. Histologically, it describes how the layers of the cornea and conjunctiva become continuous at the limbus. Surgically, it notes the anterior limbal border, blue limbal zone, mid-limbal line, posterior limbal border, and white limbal zone. The best site for cataract incisions is the mid-limbal line, while anterior or posterior incisions risk damage to underlying structures. The limbus contains stem cells that renew the corneal epithelium.
This document provides an overview of the anatomy of the uveal tract, which includes the iris, ciliary body, and choroid. It begins with an introduction and overview of the embryology and development of the uveal tract. It then discusses the anatomy and microstructure of each part of the uveal tract in detail, including their nerve and blood supply. It also briefly discusses some congenital anomalies that can affect the uveal tract.
Eyelids: Different Layer, Nerve Supply, Vascular Supply & Functions of LidsMero Eye
The document describes the anatomy of the eyelids. It discusses the embryology, layers, muscles, glands, nerve and blood supply of the eyelids. The eyelids are derived from surface ectoderm and have multiple layers including skin, muscle, fibrous tissue and conjunctiva. The main muscles are the orbicularis oculi and levator palpebrae superioris. Important glands are meibomian, zeis and moll glands. The eyelids receive motor innervation from cranial nerves and sensory innervation from the trigeminal nerve. Blood supply is from branches of the ophthalmic artery.
The document describes the anatomy and physiology of the lacrimal apparatus. It discusses the following key points:
- The lacrimal apparatus includes the lacrimal gland and associated drainage system for tear production and transport.
- The main structures are the lacrimal gland, puncta, canaliculi, lacrimal sac, and nasolacrimal duct. Tears drain from the puncta through these structures and into the nose.
- The lacrimal gland secretes tears in response to sensory nerve stimulation. Contraction of surrounding muscles aids in drainage and prevents backflow through the puncta.
- Obstruction at any point can cause excess tearing (epiphora) by
The document provides information on the anatomy and embryology of the uvea, which includes the iris, ciliary body, and choroid. It discusses the layers, blood supply, and applied aspects of each structure. The iris is the anterior-most part of the uvea and has sphincter and dilator muscles that control the pupil. The ciliary body lies between the iris and choroid and produces aqueous humor. It contains ciliary processes and muscle. The choroid is the highly vascular posterior layer that nourishes the outer retina. Common conditions like coloboma, aniridia, and heterochromia that involve the uvea are also mentioned.
The retinal anatomy document summarizes the layers and structures of the retina. It notes that the retina consists of 10 distinct layers, including the retinal pigment epithelium, photoreceptor layer, and ganglion cell layer. It describes landmarks such as the macula lutea, fovea centralis, and optic disc. The document also discusses the blood supply to the retina from the central retinal artery and choroidal capillaries, as well as the neuroglial and neurotransmitter components of the retina.
LIMBUS… • The limbus forms the border between the transparent cornea and opaque sclera, contains the pathways of aqueous humour outflow, and is the site of surgical incisions for cataract and glaucoma
2. Anatomical Limbus: Circumcorneal transitional zone of the conjunctivocorneal & corneoscleral junction Conjunctivo-corneal junction: • Bulbar conjunctiva is firmly adherent to underlying structures • Substantia propria of the conjunctiva stops here but its epithelium continues with that of the cornea. Sclero-corneal junction: • Transparent corneal lamellae become continuous • With the oblique, circular and opaque fibres of sclera
3. CONTINUE…. • In the area near limbus, the conjunctiva, tenon’s capsule & the episcleral tissue are fused into a dense tissue which is strongly adherent to corneo scleral junction.It is preferred site for obtaining a firm hold of the eyeball during ocular surgery. • The limbus is a common site for the occurrence of corneal epithelial neoplasm. • The Limbus contains radially oriented fibrovascular ridge known as the palisades of Vogt that may harbour a stem cell population. The palisades of Vogt are more common in the superior and inferior quadrants around the eye
This document describes the anatomy of the extraocular muscles and accessory organs of the eye. It discusses the six extrinsic muscles that control eye movement, including the four rectus and two oblique muscles. It also describes the eyelids, eyelashes, lacrimal apparatus, and other protective structures around the eye. The document provides detailed information on the layers of the eyelids and functions of the tears, lacrimal glands, and associated drainage system.
The cornea is the transparent front part of the eye that allows light to enter. It has six layers - epithelium, Bowman's membrane, stroma, Dua's layer, Descemet's membrane, and endothelium. The stroma makes up most of the thickness and contains collagen fibers. The endothelium maintains corneal hydration through a sodium-potassium pump. The cornea acts as a refracting surface and protects the inside of the eye. It receives nutrients and oxygen from the aqueous humor and perilimbal blood vessels to remain transparent.
The document discusses the anatomy, development and physiology of the lacrimal secretory and drainage systems. It describes the embryological development of the lacrimal system from ectodermal tissue. It details the anatomy of the lacrimal gland, puncta, canaliculi, sac, duct and nasolacrimal drainage system. It explains the physiology of tear secretion, composition of the tear film layers, and the role of nerves, blood vessels and muscles in lacrimal secretion and drainage.
The eyeball contains three layers - the outer fibrous tunic, middle vascular tunic, and inner nervous tunic. The fibrous tunic includes the sclera and transparent cornea. The middle vascular tunic (uvea) contains the choroid, ciliary body, and iris. The inner nervous tunic is the retina. Accessory structures include the eyelids, lacrimal apparatus, conjunctiva, and extraocular muscles. The interior of the eyeball is divided into the anterior and posterior chambers by the lens, filled with aqueous humor and vitreous humor respectively.
This document provides information about ocular pharmacology. It begins with an introduction to the eye's barriers that limit systemic drug access. It then describes the extraocular and intraocular structures of the eye in detail. This is followed by sections on tears, the different routes of ocular drug administration including topical, periocular and intraocular routes. Absorption, distribution, metabolism and excretion of ocular drugs are also discussed. The document provides a comprehensive overview of ocular anatomy and pharmacology.
The document summarizes key details about the anatomy and physiology of the cornea. It describes the cornea's layers, thickness, curvature, cell types, refractive power, transparency mechanisms, metabolism, innervation, and role in maintaining hydration. A new potential layer called Dua's layer is also mentioned. The summary is as follows:
The document describes the anatomy and physiology of the cornea, including its layers, cells, curvature, thickness, refractive power, and mechanisms of transparency and hydration. A potential new layer called Dua's layer is also discussed.
The document summarizes key structures and functions of the eye. It describes the three layers of the eye - outer sclera, middle choroid and vascular layer, and inner retina. It provides details on structures in each layer like the cornea, iris, ciliary body, aqueous humor, and lens. Diagrams are included to illustrate the anatomical relationships between different ocular tissues.
This document provides an overview of the anatomy and embryology of the lacrimal apparatus. It describes the secretory and drainage portions, including the main and accessory lacrimal glands, puncta, canaliculi, lacrimal sac, and nasolacrimal duct. Details are given on histology, blood supply, innervation and functions. The structure and layers of the tear film are explained. The dynamic process of tear secretion, formation, distribution, evaporation and drainage is summarized.
ocular anatomy of eye for optometry and optalomolgydevaramgehlot
The document summarizes the key anatomical structures of the eye, including the outer protective layers like the sclera and cornea, middle uveal layer containing the iris and choroid, inner retinal layer containing photoreceptors, and associated structures like the lacrimal system and extraocular muscles. The summary provides a high-level overview of the essential anatomical components and their functions in 3 sentences.
The document summarizes the key anatomical structures of the eye, including the outer protective layers like the eyelids, sclera, and cornea. It describes the inner layers like the iris, ciliary body, choroid, retina, and optic nerve. It explains the functions of various parts like tear production, intraocular fluid circulation, and the conversion of light to neural signals in the retina.
The conjunctiva is a mucous membrane that lines the eyelids and covers the sclera. It has three parts - the palpebral conjunctiva lines the eyelids, the bulbar conjunctiva covers the sclera, and the conjunctival fornix connects the other two parts. Microscopically, it has three layers - an epithelial layer, adenoid layer containing lymphoid tissue, and a fibrous layer with blood vessels and nerves. With age, the conjunctiva can develop pinguecula or pterygium, which are benign growths on the conjunctiva that can impair vision if large.
The document summarizes key aspects of eye anatomy in 3 layers:
1) The outer coat includes the cornea and sclera.
2) The middle coat contains the choroid, ciliary body, iris, and lens. It nourishes the retina and controls eye focusing.
3) The inner coat is the retina.
It also briefly describes the orbit, lacrimal system, eyelids, and extraocular muscles.
The document describes the anatomy and physiology of the cornea. It discusses the layers of the cornea from anterior to posterior: epithelium, Bowman's layer, stroma, Dua's membrane, Descemet's membrane, and endothelium. Each layer has a specialized structure and function, such as the epithelium providing a smooth surface and the endothelium maintaining corneal dehydration. The cornea is avascular and receives nutrients from the aqueous humor and tear film. Its transparency is maintained by factors such as its regular collagen structure, hydration level, and endothelial pump function.
The document summarizes key aspects of aqueous humor dynamics and glaucoma. It describes the anatomy and physiology of structures involved in aqueous humor production, circulation, and drainage, including the ciliary body, chambers of the eye, trabecular meshwork, Schlemm's canal, and collector channels. It also discusses disorders like open-angle glaucoma that can occur if intraocular pressure increases and damages vision due to resistance in the drainage system. Finally, it provides an overview of common drug classes used to treat glaucoma, such as prostaglandin derivatives, beta-blockers, alpha-2 agonists, carbonic anhydrase inhibitors, and miotics.
The document provides information on the anatomy of the eye and drug absorption through the eye. It describes the three layers that make up the wall of the eyeball - fibrous tunic, vascular tunic, and retina. It details the external structures like eyelids, cornea, iris, and pupil. Internally, it outlines the choroid, ciliary body, lens, vitreous chamber, and retina. It explains how drugs can be absorbed through the cornea or non-corneally across the conjunctiva and sclera. Factors like precorneal constraints, corneal barrier properties, and ion transport systems influence trans corneal penetration and absorption in the eye.
The document provides information about the anatomy of the eye and drug absorption. It discusses the three layers that make up the eyeball - fibrous tunic, vascular tunic, and retina. The external structures of the eye like eyelashes, eyelids, cornea, sclera, conjunctiva, and iris are described. The internal structures such as choroid, ciliary body, lens, vitreous chamber, and retina are also summarized. Key parts of the eye involved in vision like photoreceptors, blind spot, and fovea are highlighted in less than 3 sentences.
The cornea covers 1/6 of the eye's surface and is avascular and innervated. It is composed mainly of water, collagen, and proteoglycans. The cornea has five layers - epithelium, Bowman's layer, stroma, Descemet's membrane, and endothelium - which work together to maintain clarity and provide optical power. The epithelium is constantly renewed by stem cells in the limbus. The endothelium actively pumps fluid out of the stroma to prevent edema. Damage to the endothelium can compromise this pump function and clarity.
The orbit is a pyramidal cavity containing the eyeball and associated structures. It is formed by 7 bones and has 4 walls. The eyeball has 3 layers - fibrous, vascular and inner retinal layer. The orbit contains the eyeball, extraocular muscles, nerves and vessels, lacrimal apparatus and orbital fat. The lacrimal apparatus produces and drains tears to lubricate the eye.
Histology of the eye by a very good docotor in iraqi uni collage of medZaraVvv
Simple explanation about the eye, which is very specific and illustrated about histology of the eye it’s going to be very benefit and is actually very good actually benefit me very much it is published by a doctor in iraqi university. It’s illustrates the matter in a very simple way, and helps the student to understand the matter. Help to understand the histology and anatomy of the eye.
Lets fight with amblyopia || Optom Puneet Mero Eye
1. This document presents a case study of a 15-year-old female boxing player with amblyopia in the left eye who was undergoing active vision therapy.
2. Over the course of 3 visits spanning 1 month, the patient's visual acuity and stereopsis improved significantly in the left eye through continued use of active vision therapy techniques like Hart charts and Marsden balls instead of occlusion therapy.
3. The goal of vision therapy is to make the patient happy by providing faster and more effective treatment compared to traditional occlusion patching with less embarrassment and risk of reversal or non-compliance.
Velocity of sound is greater in solids than liquids and gases. It increases with increasing temperature, pressure, and humidity in gases. Stationary waves are produced in organ pipes and stretched strings. Open organ pipes allow all harmonics, while closed pipes allow only odd harmonics. End correction accounts for the pipe diameter. Velocity in strings increases with square root of tension. Interference of waves produces maxima and minima intensities, with the ratio of max to min intensity increasing with amplitude ratio.
This document discusses parallel plate capacitors and capacitor basics. It defines the capacitance of a parallel plate capacitor and explains how capacitance is affected by changing the plate area, distance between plates, and inserting a dielectric material. It also covers energy stored in a capacitor, electric field and potential, equipotential surfaces, and static electricity examples. Key points covered include the formula for capacitor capacitance and energy storage, and that capacitance increases when the plate area or dielectric constant increases but decreases when the distance between plates increases.
This document discusses the efficiency of a Carnot engine. It defines the efficiency formula as efficiency = (1 - T2/T1) x 100%, where T2 is the temperature of the heat sink and T1 is the temperature of the heat source. It then provides examples of efficiency calculations for Carnot engines working between different temperature ranges. It also discusses the temperature of the heat sink and source needed to achieve a given efficiency.
Speaker Name: Anjali
Topic: "Demystifying Nystagmus"
Hello Everyone, Namaste!! We would like to notify you all that Mero Eye Foundation is going to conduct an "EYE TALKS-Webinar", and we will be having our session live broadcast on YouTube (Session No. 118)
DATE: at, 07:300 PM NPT, 07:15 PM IST, 22nd May 2021.
YouTube links: https://youtu.be/b4G12rRvXFc
The document describes features of several ophthalmic devices from Nidek, including:
1. The AL SCAN OPTICAL BIOMETER which can measure 6 clinical parameters in 10 seconds and perform IOL power calculations.
2. The RS-3000 ADVANCE 2 OPTICAL COHERENCE TOMOGRAPHY which provides retina and glaucoma analysis with selectable OCT sensitivity.
3. The CV-9000R OPHTHALMIC SURGICAL SYSTEM which supports reusable equipment and intuitive touch screen controls for cataract surgery.
The document provides information about products from various ophthalmic equipment companies available through Vaishno Medisales. It details diagnostic devices such as topographers, OCT systems, and tonometers from Oculus, Heidelberg Engineering, and G-Medics. Refraction charts, lensometers, and slit lamps from Appasamy Associates are also summarized. The document aims to inform attendees of the Advancing Optometry Education conference about the ophthalmic solutions and technologies available through Vaishno Medisales.
The document provides information about products from various ophthalmic equipment companies that will be displayed at the Advancing Optometry Education 2021 virtual conference. It lists companies such as Oculus, Heidelberg Engineering, Metrovision, Takagi, and G-Medics and provides brief descriptions of 1-3 of their key products, such as the Pentacam HR, Spectralis OCT, Myopia Master, Corvis ST, and portable non-contact tonometer. The document aims to inform conference attendees about the latest ophthalmic technologies and equipment that will be showcased.
The document discusses the anatomy and functions of the extraocular muscles (EOMs). It describes the embryology, origin, course, insertion, nerve supply, and blood supply of the four rectus muscles and two oblique muscles. The rectus muscles originate from a common tendinous ring and insert on the sclera in a spiral pattern. Each EOM is innervated by a specific cranial nerve. Isolated paralysis of individual EOMs can cause disorders like strabismus. Conditions like dysthyroid ophthalmopathy involve hypertrophy and fibrosis of the EOMs. In summary, the document provides a detailed overview of the anatomy and clinical significance of the extraocular muscles.
Special tests for sensory and motor anomaliesMero Eye
This document contains questions and answers related to various tests used to diagnose sensory and motor anomalies. It discusses tests such as Hirschberg's test, Krimsky's test, Bruckner's test, and angle kappa measurement. It also covers tests for strabismus detection like cover tests, as well as tests for suppression like Worth's four dot test. Accommodative components and findings on MEM retinoscopy are also addressed.
The document discusses various topics related to pediatric optometry and vision testing in children. It provides multiple choice questions about the preferred methods for testing visual acuity in 4-year-olds and 8-month-olds, the process of emmetropization, common types of astigmatism in infants under 2 years old, and the types of retinoscopy used to determine refractive error in infants.
Introduction to BSV, Space perception and physiology of ocular movementsMero Eye
This document discusses binocular vision development and physiology of ocular movements. It notes that binocular vision emerges around 3 months of age as vergences develop, and stereopsis develops at 4 months. The development of accommodation and ocular movements is also outlined. The document further discusses extraocular muscle actions, innervations, the horopter, panum's fusional area, stereopsis, and methods for measuring stereo acuity in children.
Heterophoria and heterotropia refer to relative and manifest deviations of the visual axes. Statement b is wrong - in heterophoria, motor fusion is adequate to maintain alignment only when viewing with both eyes, not in higher degrees of heterophoria where suppression and high stereoscopic thresholds may be present. The most common type of phoria associated with uncorrected hyperopia is exophoria. Exophoria is also more common in hypermetropia. Oculomotor nerve palsy may be congenital, causes pupil involvement suggesting a medical cause, and warrants neuro-radiological investigation rather than just laser treatment.
Anomalies of vergence and their managementMero Eye
1. The document discusses various binocular vision anomalies including convergence insufficiency, convergence excess, accommodative insufficiency, accommodative excess, and fusional vergence dysfunction.
2. It provides the typical clinical test findings for each condition, such as near point of convergence, vergence ranges, accommodative amplitudes, and results of tests like monocular estimation method.
3. Case studies are presented and the reader is prompted to make diagnoses and suggest treatments based on the test results provided, such as prescribing glasses, vision therapy, or other treatments.
Self-assessment in optic and refraction by prof Chua, dr. Chieng, dr.ngo and ...Mero Eye
This document contains a series of multiple choice questions testing knowledge of various topics in optics and refraction, including:
1) Properties of light such as wavelength, color vision, light scattering, fluorescein angiography and indocyanine green angiography
2) Optical phenomena such as diffraction, Airy's disc, and birefringence
3) Tests of visual function including visual acuity, contrast sensitivity, and stereoscopic vision testing
4) Concepts in geometrical optics including reflection, refraction, lenses, prisms, and optical instruments.
The questions cover both basic science and clinical application of optics and refraction knowledge.
This document lists 41 books recommended for optometrists. It includes books on topics such as clinical visual optics, physiology of the eye, vision and visual perception, clinical refraction, contact lenses, binocular vision and ocular motility, low vision, and ophthalmic dispensing. The list provides the book title and author for each recommended text.
This document outlines the equipment requirements for a dispensing lab, including the number of pieces required for each item: a lensometer (3 pieces), retinoscope (4 pieces), pupillometer (3 pieces), nose pliers (3 pieces), optical screw drivers (3 pieces), lens cutter (3 pieces), lens edger (3 pieces), angling piers (3 pieces), eyewire forming pliers (5 pieces), and side cutting pliers (5 pieces).
How to Setup Warehouse & Location in Odoo 17 InventoryCeline George
In this slide, we'll explore how to set up warehouses and locations in Odoo 17 Inventory. This will help us manage our stock effectively, track inventory levels, and streamline warehouse operations.
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
Certified as an ISO/IEC 27001: Information Security Management Systems (ISMS) Lead Implementer, Data Protection Officer, and Cyber Risks Analyst, Denis brings a heightened focus on data security, privacy, and cyber resilience to every endeavor.
His expertise extends across a diverse spectrum of reporting, database, and web development applications, underpinned by an exceptional grasp of data storage and virtualization technologies. His proficiency in application testing, database administration, and data cleansing ensures seamless execution of complex projects.
What sets Denis apart is his comprehensive understanding of Business and Systems Analysis technologies, honed through involvement in all phases of the Software Development Lifecycle (SDLC). From meticulous requirements gathering to precise analysis, innovative design, rigorous development, thorough testing, and successful implementation, he has consistently delivered exceptional results.
Throughout his career, he has taken on multifaceted roles, from leading technical project management teams to owning solutions that drive operational excellence. His conscientious and proactive approach is unwavering, whether he is working independently or collaboratively within a team. His ability to connect with colleagues on a personal level underscores his commitment to fostering a harmonious and productive workplace environment.
Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
-------------------------------------------------------------------------------
Find out more about ISO training and certification services
Training: ISO/IEC 27001 Information Security Management System - EN | PECB
ISO/IEC 42001 Artificial Intelligence Management System - EN | PECB
General Data Protection Regulation (GDPR) - Training Courses - EN | PECB
Webinars: https://pecb.com/webinars
Article: https://pecb.com/article
-------------------------------------------------------------------------------
For more information about PECB:
Website: https://pecb.com/
LinkedIn: https://www.linkedin.com/company/pecb/
Facebook: https://www.facebook.com/PECBInternational/
Slideshare: http://www.slideshare.net/PECBCERTIFICATION
Philippine Edukasyong Pantahanan at Pangkabuhayan (EPP) CurriculumMJDuyan
(𝐓𝐋𝐄 𝟏𝟎𝟎) (𝐋𝐞𝐬𝐬𝐨𝐧 𝟏)-𝐏𝐫𝐞𝐥𝐢𝐦𝐬
𝐃𝐢𝐬𝐜𝐮𝐬𝐬 𝐭𝐡𝐞 𝐄𝐏𝐏 𝐂𝐮𝐫𝐫𝐢𝐜𝐮𝐥𝐮𝐦 𝐢𝐧 𝐭𝐡𝐞 𝐏𝐡𝐢𝐥𝐢𝐩𝐩𝐢𝐧𝐞𝐬:
- Understand the goals and objectives of the Edukasyong Pantahanan at Pangkabuhayan (EPP) curriculum, recognizing its importance in fostering practical life skills and values among students. Students will also be able to identify the key components and subjects covered, such as agriculture, home economics, industrial arts, and information and communication technology.
𝐄𝐱𝐩𝐥𝐚𝐢𝐧 𝐭𝐡𝐞 𝐍𝐚𝐭𝐮𝐫𝐞 𝐚𝐧𝐝 𝐒𝐜𝐨𝐩𝐞 𝐨𝐟 𝐚𝐧 𝐄𝐧𝐭𝐫𝐞𝐩𝐫𝐞𝐧𝐞𝐮𝐫:
-Define entrepreneurship, distinguishing it from general business activities by emphasizing its focus on innovation, risk-taking, and value creation. Students will describe the characteristics and traits of successful entrepreneurs, including their roles and responsibilities, and discuss the broader economic and social impacts of entrepreneurial activities on both local and global scales.
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
हिंदी वर्णमाला पीपीटी, hindi alphabet PPT presentation, hindi varnamala PPT, Hindi Varnamala pdf, हिंदी स्वर, हिंदी व्यंजन, sikhiye hindi varnmala, dr. mulla adam ali, hindi language and literature, hindi alphabet with drawing, hindi alphabet pdf, hindi varnamala for childrens, hindi language, hindi varnamala practice for kids, https://www.drmullaadamali.com
LAND USE LAND COVER AND NDVI OF MIRZAPUR DISTRICT, UPRAHUL
This Dissertation explores the particular circumstances of Mirzapur, a region located in the
core of India. Mirzapur, with its varied terrains and abundant biodiversity, offers an optimal
environment for investigating the changes in vegetation cover dynamics. Our study utilizes
advanced technologies such as GIS (Geographic Information Systems) and Remote sensing to
analyze the transformations that have taken place over the course of a decade.
The complex relationship between human activities and the environment has been the focus
of extensive research and worry. As the global community grapples with swift urbanization,
population expansion, and economic progress, the effects on natural ecosystems are becoming
more evident. A crucial element of this impact is the alteration of vegetation cover, which plays a
significant role in maintaining the ecological equilibrium of our planet.Land serves as the foundation for all human activities and provides the necessary materials for
these activities. As the most crucial natural resource, its utilization by humans results in different
'Land uses,' which are determined by both human activities and the physical characteristics of the
land.
The utilization of land is impacted by human needs and environmental factors. In countries
like India, rapid population growth and the emphasis on extensive resource exploitation can lead
to significant land degradation, adversely affecting the region's land cover.
Therefore, human intervention has significantly influenced land use patterns over many
centuries, evolving its structure over time and space. In the present era, these changes have
accelerated due to factors such as agriculture and urbanization. Information regarding land use and
cover is essential for various planning and management tasks related to the Earth's surface,
providing crucial environmental data for scientific, resource management, policy purposes, and
diverse human activities.
Accurate understanding of land use and cover is imperative for the development planning
of any area. Consequently, a wide range of professionals, including earth system scientists, land
and water managers, and urban planners, are interested in obtaining data on land use and cover
changes, conversion trends, and other related patterns. The spatial dimensions of land use and
cover support policymakers and scientists in making well-informed decisions, as alterations in
these patterns indicate shifts in economic and social conditions. Monitoring such changes with the
help of Advanced technologies like Remote Sensing and Geographic Information Systems is
crucial for coordinated efforts across different administrative levels. Advanced technologies like
Remote Sensing and Geographic Information Systems
9
Changes in vegetation cover refer to variations in the distribution, composition, and overall
structure of plant communities across different temporal and spatial scales. These changes can
occur natural.
Leveraging Generative AI to Drive Nonprofit InnovationTechSoup
In this webinar, participants learned how to utilize Generative AI to streamline operations and elevate member engagement. Amazon Web Service experts provided a customer specific use cases and dived into low/no-code tools that are quick and easy to deploy through Amazon Web Service (AWS.)
This document provides an overview of wound healing, its functions, stages, mechanisms, factors affecting it, and complications.
A wound is a break in the integrity of the skin or tissues, which may be associated with disruption of the structure and function.
Healing is the body’s response to injury in an attempt to restore normal structure and functions.
Healing can occur in two ways: Regeneration and Repair
There are 4 phases of wound healing: hemostasis, inflammation, proliferation, and remodeling. This document also describes the mechanism of wound healing. Factors that affect healing include infection, uncontrolled diabetes, poor nutrition, age, anemia, the presence of foreign bodies, etc.
Complications of wound healing like infection, hyperpigmentation of scar, contractures, and keloid formation.
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
তাই একজন নাগরিক হিসাবে এই তথ্য গুলো আপনার জানা প্রয়োজন ...।
বিসিএস ও ব্যাংক এর লিখিত পরীক্ষা ...+এছাড়া মাধ্যমিক ও উচ্চমাধ্যমিকের স্টুডেন্টদের জন্য অনেক কাজে আসবে ...
2. Anatomy Tear film
The tear film has four
main functions:
optical, mechanical,
nutritional, and
Defensive
PH: 7.45
3. • Tear film has a total volume of 7–10 μL
• Normal basal tear production rate is 1–2 μl/min
• Reflex tear rate is >100 μl/min
• Normal tear volume turnover occurs every 5–7 min.
4. • Lipid Layer (0.1 μm):
- Meibomian glands with additional contributions from the glands of Moll and
Zeiss
• A rapid (<10 s) tear fi lm breakup time is a sign of lipid layer insufficiency.
Meibomian glands are 20-30 in numbers per tarsals. Content are holocrine
secretion.
• Meibomian secretion occurs on blinking due to contraction of the muscle of
Riolan.
• Its sebaceous gland
Glands of Moll: modified sweat glands. open into the eyelash hair follicle.
Glands of Zeiss: sebaceous glands. open at the lid margin or into eyelash
5. Aqueous Layer (7 μm):
• 95 % is from lacrimal gland secretion; 5 % from the accessory glands of Krause and
Wolfring.
• Sjogren syndrome
6. • Mucus Layer (3–30 μm):
- Mucins (glycoproteins) secreted by conjunctival goblet cells.
- Water and electrolytes secreted by conjunctival goblet and non – goblet epithelial cells.
• Mucin is stored in large secretory granules at apical surface of goblet cells.
• Goblet cell are Merocrine.(Eccrine). Density more at nasal conjunctiva.
• increased breakup of tears and symptoms of dry eye
• Glycocalyx is a membrane-bound network of mucins attached to
• The apical microvilli of corneal and conjunctival epithelial cells
7. • Lacrimal Gland:
- lobulated tubuloacinar gland . ( branced tubes)
- Divided into superior orbital part and an inferior palpebral part.
- acini consist of columnar secretory cells .
- produce IgA that is secreted in tears.
- parasympathetic fi bers from the lacrimal nucleus of the pons
Reflex tear secretion:
• Peripheral sensory stimulation (e.g., of the cornea, conjunctiva, nose) is
mediated by the trigeminal nerve.
• Central stimuli may be related to light (optic nerve as afferent arm) or
emotion (e.g., weeping).
8. Anatomy of Conjunctiva
• mucus for the tear film
• Protection of the ocular surface by barrier function
• Defense against pathogens as an element of the mucosa-associated
lymphoid tissue ( MALT )
• Provision of limbal stem cells to maintain and heal the corneal and
conjunctival epithelia.
• Epithelial stem cells located at the palisades of Vogt in the corneal
limbus
9. • bulbar conjunctiva lines the sclera; the palpebral conjunctiva lines the eyelid inner
surface.
• Conjunctiva consists of a surface epithelium and an underlying substantia propria .
Epithelium:
• two- to three-cell layer non-keratinized cuboidal stratified epithelium.
Substantia propria:
• substantia propria is highly vascular and contains immune cells (mast cells, plasma cells,
neutrophils, and lymphocytes)
• Two layers: Adenoid layer(contains lymphoid tissue and absent in infants)-no follicle and
Deep Fibrous Layer
10. Conjunctival Tear Film Contribution
• Crypts of Henle eyeball's conjunctiva, arranged in a ring around the
cornea, near the scleral junction. Secrete mucin. Its non goblet cell.
• glands of Krause are mostly forniceal; 20 in the superior and 6–8 in the
inferior fornix.
• glands of Wolfring are in the tarsal conjunctiva of the upper and
occasionally lower lid.
11. Lacrimal Drainage System
• punctum , a 0.3 mm opening located
on the medial eyelid margin
• canaliculus , a 10 mm tubule that
traverses the medial eyelid
• canaliculi are surrounded by
orbicularis oculi fibers.
• valve of Rosenmuller at the
common canaliculus opening
prevents to a variable extent reflux
from the sac.
• valve of Hasner is often present at
the nasal end of the duct to prevent
refl ux
• Tear goes to canaliculi by capillary
attraction and Lid movement
12. Anatomy of Cornea
• Prolate shaped, with a 12.6 mm
horizontal and a 11.7 mm vertical
diameter, central cornea is spherical.
• cornea transmits wavelengths 310 –
2500 nm
• Refractive index of 1.376.
• + 48.9 D from the anterior corneal
surface/tear film
• − 5.8 D from the posterior corneal
surface
• Total Power: + 43.18 diopters
• Corneal curvature:
- Anterior: 7.8 mm
- Posterior: 6.5 mm
• with-the-rule astigmatism
The central corneal thickness is 0.53 mm, whereas the corneal periphery is 0.71 mm thick
13. Corneal epithelium
• Stratified, non-keratinized, squamous
epithelium
• Five to seven cell layers deep
• Cell turnover, from basal cell division to
superficial cell sloughing, occurs in 7–10
days
• Three cell types (from surface to
basement membrane): superficial ,wing ,
and basal cells
Superficial cells have apical surface projections
(microvilli).
Basal cells form a single layer of cuboidal cells. Mitotic
activity an stem cells activity from this layer.
Basal cells rest on a basement membrane of type IV
collagen, laminin, fibronectin and fibrin
Cell-cell adhesion:
Desmosomes attach basal, wing, and superficial
cells to one another. (macula adherens)
Tight junctions encircle superficial cells. (zonula
occludens)
Gap junctions are numerous among basal and
wing cells. These allow intercellular
communication
14. Corneal
Stroma
• Makes up 90 % of corneal thickness.
• Bowman ’s layer is acellular non-regenerating membrane. It consists of is compact fibers from
stroma. Consists predominantly type I collagen.
• Stroma lamellae:
- 200 – 250 highly organized lamellae by collagen fibers.
- Parallel fibers centrally and orthogonal peripherally to give cornea stability.
- ground substance consisting of a proteoglycan matrix
- Keratocytes are the main stromal cell type and they synthesize fibrillar collagen and help in wound
healing.
15. Dua’s Layer:
Descemet’s Membrane:
• Descemet’s membrane is a 10–15 um thick basement membrane of the corneal endothelium.
• Type IV collagen
• Toughest layer and relatively resistant to proteolytic enzymes
• Thickened area of collagenous connective tissue may be seen at the membrane’s termination in the
limbus; this circular structure is called Schwalbe’s line
Endothelium:
• Endothelial cells generally do not replicate. Polymegatheism.
• Newborns have 5500 cells/mm 2 , while adults have 2500–3000 cells/mm 2 .
• A minimum of 400–700 cells/mm 2 is required for normal corneal function.
• Stressed or unstable endothelium demonstrates polymegathism (cells of varying size) and
pleomorphism(cells of varying shape)
• Periodic thickenings of endothelium in Descemet’s membrane located near the corneal periphery are
called Hassall-Henle bodies and located at central cornea are called corneal guttata
• FUCHS’ DYSTROPHY (see Figure 2-16) is a bilateral, noninflammatory loss of endothelial function
16. Corneal
Innervation
• Corneal nerves are non-myelinated.
• The cornea is innervated by the anterior ciliary nerves, branches of the ophthalmic nerve (V1).
• NEUROTROPHIC KERATITIS is a rare degenerative disease caused by the loss of corneal
sensory innervation.
17. Anatomy of Sclera
• The sclera is a tough , opaque collagen coat. Its relatively Avascular. collagen type I
• the sclera is opaque due to:
(a) Increased water content (70 %)
(b) Larger diameter and more interwoven collagen fibrils
• Episclera is a dense vascular connective tissue making up the superficial portion of the sclera
The posterior sclera contains perforations for the:
(a) Optic nerve (scleral canal and lamina cribrosa)
(b) Long and short posterior ciliary arteries
(c) Ciliary nerves
(d) Short ciliary veins
(e) The vortex veins
18. Anatomy of Lens:
• Biconvex, contained within capsule. (16-17 Diopters power).
Crystallin proteins.
• Anterior single layer of cuboidal epithelial cells.
• Radius of curvature: Anterior: 11.mm Posterior: −6.5mm
• Refractive index: Periphery to center: 1.362–1.406
• Anteroposterior diameter of lens: Young (20 yrs) 3.5–
4.0mm Old age ( 70 yrs) 4.5–5.0 mm
• The anterior suture is an upright- Y shape and the
posterior suture an inverted-Y shape, embryonic suture.
• The area occupied by the zonules is the canal of Hannover,
and the retrozonular space, the area from the most posterior
zonules to the vitreal face, is the canal of Petit
19. Lens Capsule
• lens capsule is an elastic basement membrane,
composed of type IV collagen.
• Thickest in the anterior midperiphery (21 μm). At the
anterior pole it is 13 μm; it is thinnest at the posterior
pole (4 μm).
Lens Epithelium:
• Epithelium is a monolayer of cuboidal cells inside the
anterior and equatorial capsule.
20. • Lens proteins: Crystallins make up 40 % of the wet weight of lens fibers.
• Alpha crystallin (30 % of total lens protein) and Beta/gamma crystallin (56 % of total lens protein).
• Glucose is the principal carbohydrate of the lens. It enters the lens from the aqueous by simple diffusion
and insulin-dependent facilitated transfer .
• Anaerobic metabolism is highly prevalent in the lens, compared to most body
21. Parasympathetic nerves
• The ciliary muscle is supplied by parasympathetic fibers of the oculomotor nerve.
• These originate in the midbrain Edinger-Westphal nucleus and synapse in ciliary
ganglion.
• Parasympathomimetic agents (e.g., pilocarpine) stimulate accommodation.
• Cycloplegic agents (muscarinic antagonists, e.g., cyclopentolate) block
Accommodation.
22. The Ciliary Body anatomy
• ciliary body is continuous with the iris anteriorly and the choroid. (uveal layer)
• The ciliary body has two main functions:
(a) Production of aqueous fluid
(b) Accommodation via ciliary muscle contraction
It consists of the ciliary muscle, ciliary stroma, and ciliary epithelium.
It extends anteriorly to the scleral spur, where it is firmly attached to the sclera.
It is divided into the anterior pars plicata and the posterior pars plana.
23. • The inner surface of the pars plicata is
corrugated, with ciliary processes
extending from 70 ridges.
• Aqueous fluid formation occurs over
the ciliary double epithelium.
• It has three smooth muscle fiber
groups: longitudinal (outer), radial,
and circular (inner).
24. The ciliary muscle
• It has three smooth muscle fiber groups:
longitudinal (outer), radial, and circular (inner).
• On accommodation all muscle groups contract,
releasing tension on the zonules.
The ciliary stroma
• highly vascularized, loose connective tissue.
• It contains multiple capillaries that have fenestrated
endothelium
• Fluid accumulates in the stroma by bulk flow across
the capillary endothelium.
• This fluid is the reservoir of ultrafiltrate from which
aqueous is secreted.
The ciliary epithelium
a. Outer pigmented epithelium (PE) cuboidal and
b. Inner non-pigmented epithelium Columnar. Highly
active and active secretion of Aqueous.
25. Aqueous Fluid
• Aqueous fluid is formed by the ciliary body and secreted
into the posterior chamber.
• The fluid traverses the pupil to enter the anterior chamber
and exits the eye through one of the two drainage
pathways
(a) The trabecular meshwork (TM) route
(b) The uveoscleral route
Aqueous fluid is formed through diffusion, ultrafiltration, and
active secretion
• Diffusion and ultrafiltration form a reservoir of plasma in
the ciliary stroma. (pressure dependent)
• Active secretion of aqueous from ultrafiltrate occurs across
the ciliary epithelium. (energy dependent)
The aqueous is produced at 2.6 μl/min
26. Aqueous Drainage from the
Eye
The trabecular meshwork route
• Aqueous traverses the TM, across the inner wall of Schlemm’s canal (SC) (50–75 %)
• From there it passes into collector channels, aqueous veins, and into episcleral veins.
The uveoscleral route
• This occurs freely as the anterior ciliary body and iris root lack an endothelial lining .
• The fluid then passes into the suprachoroidal space and exits the eye through the sclera via scleral
perforations or the vortex veins.
• Uveoscleral flow is IOP independent at IOP levels greater than 7 mmHg.
In the anterior chamber, the aqueous circulates in convection currents, moving down along the
cooler cornea and up along the warmer.
27. Trabecular Meshwork and Schlemm’s Canal
• The TM is located at the angle of the eye
near the insertion of the iris root.
• It extends from Schwalbe’s line anteriorly to
the scleral spur posteriorly.
• It has three parts: the uveal (inner),
corneoscleral, and juxtacanalicular
(outer)layers
28. • Average adult IOP is 10-21 mmHg
• IOP demonstrates diurnal variation with a typical mid-morning increase by 5 mmHg;
this may be related to early morning cortisol levels
29. Anatomy of the Iris
• The iris contains two muscles: the sphincter and dilator pupillae .
• pupil size to vary from 1 to 9 mm.
• The iris consists of an anterior stromal layer and a posterior double-layered epithelium
• The sphincter(parasympathetic Nerves) and dilator muscles(sympathetic Nerves) are located
within the stroma.
Iris epithelium-
• 2 iris-pigmented epithelial layers
• Anterior is continuous with the outer pigmented ciliary body epithelial layer.
• The posterior is continuous with the inner non-pigmented ciliary body epithelial layer.
30. The Pupil
• The light reflex is a
parasympathetic-mediated
pupillary constriction to
light.
• The neural pathway consists of
afferent , interneuron , and
efferent divisions
• Direct vs Consensual light
reflex.
31. Afferent division
• Photoreceptor cells
• intrinsically photosensitive ganglion cells (ipRGC)
• Optic nerve
Interneuron division
• equal bilateral projections to the Edinger-Westphal (E-W)
nuclei
Efferent division
• Oculomotor nerve
The Near Reflex
• triad of ocular convergence ,
pupillary constriction , and
accommodation
32. Horner’s syndrome-
• Horner’s syndrome is caused by a
lesion in the sympathetic pathway
to the eye
• 1% Phenylnephrine test: Miosed
pupil affected and dilated after the
drop.
33. Adie’s tonic pupil- iris sphincter denervation
Relative afferent pupillary defect (RAPD)-The swinging flashlight, or Marcus
Gunn test, aims to detect inequality of visual input from either eye (a RAPD)
Light-near dissociation(Agryll Robertson Pupil)- Accommodation Reflex
present
36. Macula Lutea:
• Antioxidant carotenoid pigments (lutein and zeaxanthin) give the macula a yellow hue.
a) Fovea centralis
• fovea centralis is a small depression at the central macula that provides highest visual acuity.
• The depression is due to centrifugal displacement of inner retinal cells to maximize image clarity.
• Vessels are absent from the central fovea ( foveal avascular zone ) to minimize light scattering.
b) The parafovea
• The fovea is surrounded by the parafovea which is in turn surrounded by perifovea.
• With increasing eccentricity the density of cones decreases while the density of rods rises to peak
at approximately 20 0 off fixation
37. Photoreceptor
Cells
• Photoreceptor cells convert light into neural
signal by phototransduction .
Outer Segment and Inner Segment
• Cone outer segments (OS) are conical with a
tapered end; rod outer segments are non-
tapered.
• The outer segments consist of 600–1000 disks
made of bilayered lipid membrane.
• Rod Spherules Cone pedicels.
• Resting membrane Potential of −50 mV
43. RPE ( Retinal Pigment Epithelium)
- Pigmented layer of retina attached to choroid.
- Prevents scattering of light increasing contrast and visual sensitivity.
- Tapetum in cat, dog, tigers etc. night glow.
44. Horizontal Cells
• Horizontal cells (HCs) have long branching
dendritic processes that form interconnections
between photoreceptor cells and bipolar cells.
• Use the inhibitory neurotransmitter GABA .
• Involved in feedback mechanism based on
Photoreceptor response.
• Send inhibitory response to Photoreceptor and
Bipolar cells.
45. Bipolar Cells
• Bipolar cells (BCs) carry signal from
photoreceptor cells to ganglion cells
and amacrine cells .
• use glutamate as their
neurotransmitter.
• BCs can be classified into cone and
rod Bipolar Cells.
• There are at least 11 cone bipolar
types which contact cones and a
single type of rod bipolar cell which
contact rods.
46. Amacrine Cells
• There are at least 40 types of amacrine cell.
• Receive excitatory signal from Bipolar and provide inhibitory input to
Bipolar, other amacrine and ganglion cells.
• Release of glycine or GABA
• Some are dopaminergic , projecting widely and facilitating light adaptation
in the retina.
• Helps in Edge Detection.
47. Ganglion Cells
• 14–20 morphological GC types exist.
• P (midget) and M (parasol) channels
Midget Ganglion (P-ganglion) (Parvocellular Pathway)
- Color vision, contrast and fine vision (VA)
Parsol (M-ganglion) (Magnocellular Pathway)
- Temporal vision.
- Larger in size , affected first in glaucoma. Give results to Frequency doubling Visual field
test.
IpRGC (Intrinsic Photosensitive Retinal Ganglion cell):
- Photosensitive (like rods and cones)
- Control Circardian rhythm
49. Lateral Geniculate Body
• Third order neurons of vision
• Consists of six layers of neurons alternating with white matter(formed by
optic fibres).
• Dorsal 4: Parvocellular layer
• Ventral 2: Magnocellular Layer
• Middle layers: Konio-cellular layers
50.
51. VISUAL CORTEX
• Primary visual cortex:V1,striate cortex,Brodman area 17
• Horizontal calcarine fissure divides the medial surface of the occipital lobe.
• Its the visuosensory area.
• Impulses originating from corresponding points of two retina meet here.
51
52.
53. Neurotransmitters
Glutamate: Glutamate is the predominant excitatory neurotransmitter within the retina.
GABA and glycine: Gamma-aminobutyric acid ( GABA ) and glycine are inhibitory
neurotransmitter
Dopamine: Dopamine is a modulatory retinal neurotransmitter
• Acetylcholine: Acetylcholine is a fast excitatory neurotransmitter released by starburst
amacrine cells
54. Anatomy of the Orbit
• The skull bones can be
divided into two parts: the
cranial bones and the facial
bones
• Total 22 bones
• Cranial: 8
• Facial: 14
Orbit: 7 bones
55.
56. ORBITAL WALLS:
a) Roof: orbital plate of the frontal bone in front and
lesser wing of the sphenoid contributes a small
posterior portion.
- Lateral of Frontal bone: fossa for the lacrimal gland.
- Medial of the Frontal bone : trochlea.
b) Floor: orbital plate of the maxillary bone, orbital
plate of the zygomatic bone in front and the small
orbital process of the palatine bone behind.
Commonly affected in blow-out fracture.
c) Medial Wall: formed by the frontal process of the
maxilla, the lacrimal bone, the orbital plate of the
ethmoid, and a part of the body of the sphenoid.
Thinnest Wall.
d) Lateral Wall: zygomatic bone in front and of the
greater wing of the sphenoid bone behind
57. superior orbital fissure is the gap between the lesser wing and the greater wing
of the sphenoid bone.
The optic foramen or the optic canal, lies in the lesser wing of the sphenoid.
The lacrimal bone (one in each orbit) is the smallest bone of the face and
articulates with the maxillary bone, ethmoid bone, and frontal bone.
Total Bones in Orbit: 7
Sphenoid, Frontal, Zygomatic, Ethmoid, Lacrimal, Maxilla, Palatine
• Orbit Volume: 30 cc
• 35 mm high and 45 mm wide
• Rim to the orbital apex measures 40 to 45 mm in adults
• Lateral walls of the two orbits are set at approximately a right angle from one
58. Optic Nerve and Pathway
• Second Cranial Nerve (Afferent) : 5 to 6 cm long
The optic nerve consists of:
(a) Retinal ganglion cell (RGC) axons
(b) Supportive glial tissue
(c) Vascular tissue
• It is surrounded by three layers of meningeal tissue (pia, arachnoid, and dura).
• Each nerve covered by oligodendrocyte rather than Schwan cell (hence Retina is called Part of
Brain) and affected in Multiple Sclerosis.
59. • RGC axons from the RNFL turn 90° to dive into
the disc to form the neuroretinal rim.
• RGC axons exit the eye through pores of the
lamina cribrosa , a perforated portion of sclera
that provides structural support to the optic nerve
head.
• Intraocular portion (0.7 to 1 mm)
• Intraorbital portion (30 mm)
• Intracanalicular(6 to 10 mm)
• Intracranial portion (10 to 16 mm).
60. Topographic Organization
• Superior and inferior fibers are segregated by the
horizontal raphe (H) which divides the inferior and
superior visual fields .
• Temporal macular fibers (T) course around the fovea
(F) to enter the disc superiorly or inferiorly.
• Nasal macular fibers travel in the papillomacular
bundle (P) to enter the temporal aspect of the optic
disc.
61. • 90% of which will terminate in the LGN. Approximately 10% project to areas controlling pupil
responses or the circadian rhythm.
• LGN: conscious visual perception .
Pretectal nucleus:
• Each pretectal nucleus (in the dorsal midbrain) receives bilateral optic nerve projections.
• Each projects bilaterally to the Edinger–Westphal nuclei.
• They are involved in controlling the pupillary light reflex
62.
63.
64.
65. • Superficial nerve fiber: Central Retinal Artery
Occasionally from the Cilioretinal Artery
• The posterior ciliary arteries each provide a
variable, segmental supply to portions of the optic
nerve below its head.
• Distal portions: arterial plexus.
• Within optic canal: internal carotid artery
• Intracranial segment: internal carotid, anterior
cerebral, or anterior communicating arteries
66. Hyaloid artery develops as a bud from Bergmeister’s Papilla (from center of optic
disc)
The ISNT rule is an easy way to remember how the optic nerve is supposed to look in a normal eye.
67. Anatomy of eyelids
• Barrier function
• Maintenance of globe position
• Ocular surface integrity
•
• Eyelid glands
• Normal interpalpebral fissure height is 8–11 mm;
• Horizontal Palpebral fissure length is 27–30 mm.
• The upper lid margin rests 1.5–2 mm below the
limbus; the lower rests on the limbus
69. Anterior Lamellae
• Skin, muscle (orbicularis
oculi (OO)), and associated
glands
• Cilia: There are 100–150 on
the upper lid and 75 on the
lower lid and are replaced
every 3–5 months.
70. Posterior Lamellae:
Tarsal plate, conjunctiva, and associated glands
• Tarsal Plate: Dense fibrous tissue 1–1.5 mm thick and 25
mm wide.
- Upper lid the height varies from 8 to 12 mm, in the lower lid 3–
4 mm
- The tarsal plate contains the Meibomian glands, 25 in the
upper and 20 in the lower lid.
71. Eyelid movements
Opening:
- Levator palpebrae superioris muscle (innervated by 3rd
nerve) elevates the upper eyelid approximately 15 mm.
- Muller’s muscle (smooth muscle, sympathetically
innervated) contributes an additional 1–2 mm of upper lid
elevation.
- The lower lid is moved inferiorly (5 mm) by the inferior
retractors linked to the inferior rectus and inferior oblique by
the capsulopalpebral fascia.
Closing:
- Closure is due primarily to Orbicularis Oculi contraction.
(innervated by 7th nerve)
Horner’s syndrome: partial (1–2 mm) ptosis due to loss
of Muller’s muscle function.
Oculomotor (third) nerve palsy: Complete Ptosis
LAGOPHTHALMOS refers to incomplete closure of the
eyelids
72. Blinking:
- spontaneous, reflex, or voluntary.
a) Spontaneous blinking:
- This occurs at rate of 10-20 times/minute.
Affected by:
- Environment (dry, moist, dust, bright), Emotional state (anxiety, concentration), Some disease(e.g.,
Parkinson’s disease)
b) Reflex blinking:
- Tactile: (touch), Optical: dazzle (bright lights) , Auditory (menace)
- For Tactile reflex trigeminal nerve (afferent arm) and facial nerve (efferent arm).
C) Voluntary blinking:
73. Madarosis (loss of eyelashes)
Trichiasis (misdirected growth of eyelashes)
Distichiasis (extra row of eye lashes)
Lagophthalmos refers to incomplete closure of the eyelids
Poliosis: White eyelash
Blood Supply by:
- Medial and Lateral palpebral arteries are branches of the ophthalmic and lacrimal arteries,
respectively.
76. 6thCavernous Sinus:
3, 4,5 nerve: wall of Cavernous Sinus
6th nerve: Floor of Cavernous Sinus
- Hence easily affected with raised ICP and
carotid artery pressure
77. Oculomotor: 3rd Nerve
• Motor Nerve
• LPS and all extra ocular muscles except lateral rectus and superior oblique (LR6SO4)
Components:
Somatomotor Component: Supply Extraocular muscles ( from oculomotor Nucleus)
Visceromotor(Parasympathetic): Ciliary body and Sphincter pupillae (Edinger Westphal Nucleus)
General somatic afferent: for proprioceptive impulses from the medial rectus muscle
80. Trochlear: 4th Nerve
• Motor Nerve
• Innervates only Superior Oblique muscle
• Only cranial nerve that exits from the dorsal (rear) aspect
of the brainstem.
• Smallest Cranial nerve based on number of axons.
• Longest intracranial length.
• Most commonly affected due to head trauma.
• Supply contralateral side
Palsy:
- Esotropia
- Hypertropia
- Excyclotropia
81. Trigeminal: 5th Nerve
• Mixed nerve (motor/sensory)
• Only nerve to grow from organ to
brain
83. Ophthalmic Branch:
- sensory innervation
• Frontal nerve:
(Largest Branch of three)
• Lacrimal nerve:
(Smallest Branch of three)
• Nasociliary nerve
Supraorbital Upper eyelid and conjunctiva, Scalp
Supratrochlear
Upper eyelid and conjunctiva,
Forehead
• Sensory innervation of lacrimal gland, upper eyelid and
conjunctiva.
• Contains parasympathetic fibers to lacrimal gland.
Long ciliary nerves
Sensory innervation to eye (cornea, ciliary
bodies, iris)
Contains sympathetic fibers to dilator
pupillae muscle.
84. Abducens: 6th Nerve
• Motor nerve
• Supply Lateral Rectus muscle
• Somatic efferent: for lateral movement of the eye
• General somatic afferent: for proprioceptive
impulses from the lateral rectus muscle.
• Raised ICP affects 6th nerve first.
• Lesions of the intracavernous part of sixth nerve
may cause Tolosa-Hunt Syndrome.
Palsy:
- Esotropia
85. Facial: 7th Nerve
• Mixed (Sensory and Motor)
• General visceral efferent : parasympathetic
supply of the lacrimal gland.
- Reflex Tearing
• Somatic motor fibers
• Eye closure (orbicularis oculi)
Bells Palsy:
Hemifacial Paresis