Retina and Aqueous Drainage and Crystalline Lens

It extends from the optic disc to the Ora Serrata and it appears purplish-red due to the visual purple of the rods and underlying vascular choroid

Retina

It contains the photochemicals and neurologic connections that process light energy and relay it to our visual cortex for visual perception

Retina

The transparent neural tissue lining the posterior two-thirds of the eye. It is called the “the color film” of our visual system

Retina

Innermost tunic of the eyeball and delicate and transparent membrane and is also most highly-developed tissue of the eye

Retina

Porous, spongy tissue located at the junction of cornea and iris and it is responsible for maintaining intraocular pressure (IOP)

Trabecular Meshwork

If this is blocked, it will lead to more pressure (IOP) and may lead to glaucoma or primary open-angle glaucoma

Trabecular Meshwork

It drains aqueous humor from the anterior chamber into schlemm’s canal

Trabecular Meshwork

Sensitive part of the retina because it has concentration of the cones ( more cones )

Fovea Centralis

Blood supply of the innermost half of the retina and branches from the ophthalmic artery 

Central Artery of Retina

It is typically the first intracranial branch of the internal carotid artery

Ophthalmic artery

Blood supply that nurtures the Retinal Pigment Epithelium and the outer portion of the sensory retina adjacent to the choroid

Choriocapillaris

It is responsible that gives most of the peripheral visual field

Rods

It is responsible for color vision and seeing fine details

Cones

It is a pink colored, well defined circular area of 1.5mm diameter and all the retinal layers exterminate here except the nerve fibers which pass through the cribrosa to run into the optic nerve

Optic Disc

Because this area is packed with nerve fibers and is also the entry/exit point for the major blood vessels that serve the retina, there is no room for photoreceptors (rods and cones)

Optic Disc

There a depression part seen in the optic disc and it is called:

Physiological Cup

The central retina and central retinal vein emerge through the center of this 

Physiological Cup

Area of blindness in the visual field marking the site of the optic nerve in the eye where there are no photoreceptors

Blind spot of Mariotte

It is first described by Edme Mariotte in the 1660s and the corresponding gap in your visual field is called a:

The physiological blind spot

It is called the yellow spot and it is about 5.5mm in diameter

Macula Lutea

It is comparatively deeper red than the surrounding fundus and is situated at the posterior pole temporal to the optic disc

Macula Lutea

Its primary job is to provide high visual acuity that when you look at object your eye muscles move to focus its image precisely. 

Fovea Centralis

The central depressed part of the macula

Fovea Centralis

It is about 1.5mm in diameter and is the most sensitive part of the retina because it is composed of cones

Fovea Centralis

It is a center of fovea centralis where there is a shining pit called:

Foveola

It is 0.35mm in diameter which is located about 2 disc diameters (3mm) away from the temporal margin of the disc and about 1mm below the horizontal meridian

Foveola

It is the serrated peripheral margin where the retina ends. And the retina is firmly attached both to the vitreous and the choroid.

Ora Serrata

This is where the pars plana extends anteriorly

Ora Serrata

Five main functions the determine the function of the sensory retina:

Visual acuity, dark adaptation, color vision, central and peripheral visual fields, and electroretinography

A test used to determine the health and function of the sensory retina

Electroretinography

The capacity to see fine detail, sharpness, and clarity

Visual Acuity 

A non-stop process by which the sensory retina dramatically increases its sensitivity to light when moving from a brightly lit environment to a dim or dark one.

Dark Adaptation

It is entirely dependent on a specific type of photoreceptor cell, the cone, which identified as being responsible for central vision.

Color Vision

Electrical event messages move from one location to another in the form of action potentials along axons

Nerve Impulses

At synapse, the impulse must pass between two neurons and they are:

Presynaptic neuron and postsynaptic neuron

A transition from the scleral curvature to the steeper corneal curvature which can cause a settling of pigment in the area

Schwalbe’s Line

It is the anterior border of the trabecular meshwork and the posterior border of Descemet’s membrane and it occurs in a 50um to 150um transition between the trabecular meshwork and the corneal endothelium

Schwalbe’s Line

A sieve-like structure at the angle of the anterior chamber through which 90% of aqueous humor leaves the eye

Trabecular Meshwork

The innermost portion of TM, consisting of cord-like endothelial cell-covered strands arising from the iris and ciliary body stroma

Uveal Meshwork

The intertrabecular spaces are relatively large and offer little resistance to the passage of aqueous

Uveal Meshwork

It lies to the uveal meshwork to form the thickest portion of the trabeculum. It is composed of layers of connective tissue strands with overlying endothelial-like cells.

Corneoscleral Meshwork

The middle layer and its intertrabecular spaces are smaller than those of the uveal meshwork, conferring greater resistance to flow

Corneoscleral Meshwork

The outer part of the trabeculum and links the corneoscleral meshwork with the endothelium of the inner wall of the Schlemm canal

Juxtacanalicular Meshwork

It consists of cells embedded in a dense extracellular matrix with narrow intercellular spaces, and offers the major proportion of normal resistance to aqueous outflow

Juxtacanalicular Meshwork

A circumferential channel within the perilimbal sclera. The inner wall is lined by irregular spindle-shaped endothelial cells containing infoldings that are thought to convey aqueous via the formation of the transcellular pores.

Schlemm Canal

The outer wall is lined by smooth flat cells and contains the openings of collector channels, which leave the canal at oblique angles and connect directly or indirectly with episcleral veins

Schlemm Canal

The trabeculae that span the lumen (interior space of Schlemm Canal) into 2-4 channels

Septa

The anchor point for drainage. The base for trabecular meshwork and its muscle to control the outflow of the aqueous humor.

Scleral Spur

It is produced from plasma by the ciliary epithelium of the ciliary body pars plicata, using a combination of active and passive secretion

Aqueous humor

Aqueous bulk flow through the trabeculum into the Schlemm canal and the the episcleral veins

Trabecular Outflow 90%

Aqueous passes across the face of the ciliary body into the suprachoroidal space, and is drained by the venous circulation in the ciliary body, choroid, and sclera

Uveoscleral Drainage 10%

Some aqueous also drains here

Iris

What is the normal values of Intraocular Pressure

10-20 mmHg

What is the production rate of Aqueous Humor?

2-6 uL per minute

What is the volume of Aqueous Humor?

0.2 ml

When does the Aqueous Humor replace?

1-2 hours

The nerve fiber layer of the sensory retina and pass in the optic nerve to synapse in the lateral geniculate body and the pretectal region

The axons of ganglion cells

Adhesion between the iris and adjacent structure

Synechiae

Type of synechiae that its adhesion is between the iris and the cornea

Anterior Synechiae

Type of synechiae that occurs with unrelieved attacks on angle-closure glaucoma and may occur following injury or surgery when the anterior chamber does not form

Peripheral Anterior Synechiae

Type of synechiae that is adhesion is between the iris and the lens as occurs commonly in uveitis

Posterior Synechiae

Gold standard of IOP measurement

Goldmann Applanation Tonometer