Retina A thin transparent and delicate membrane which is the innermost layer of the eyeball.

It extends from optic disc to ora serrata.

Grossly it is divided into

Posterior pole

Peripheral retina

Posterior pole includes two areas

Optic disc

Macula lutea

Optic disc

Optic disc: a well defined circular area of 1.5-2mm diameter.

Here all the retinal layers terminate except the nerve fibres

A depression is seen in the disc called as Physiological cup

Significance of physiological cup: the central retinal arteyand vein emerge through the centre of this cup

Macula lutea

Also called as the Yellow Spot

It is about 5.5 mm in diameter

Fovea centralis is the central deeper part of macula (1.5mm in diameter) which is the most sensitive part of the retina

In its centre a shining pit called foveola is located

Internal limiting membrane

Nerve fibre layer

Ganglion cell layer

Inner plexiform layer

Inner Nuclear layer

Outer plexiform layer

Outer nuclear layer

External limiting membrane

Layers of rods and cons

Retinal Pigmented epithelium

Functional division of retina

Temporal retina Nasal retina

Nerves arising from temporal retinaPass through optic nerve and optic tract of same side to terminate in Ipsilateral

Geniculate body

Nerves arising from nasal retinaPass through optic nerve cross in

optic chiasma and travel to contra lateral optic tract and eliminate in

contra lateral geniculate body

Blood supply

Outer four layers are supplied by choroidal vessels

Inner six layers are supplied by central retinal artery , a

branch of Ophthalmic artery

Disease of retina

Congenital and

developmental disorders

Inflammatory disorders

Vascular disorders

Macular disorders

Dystrophy and degenerative

disorders

Retinal detachment

Tumors

Congenital and developmental disorders

Anomalies of optic disc

Crescents

Situsinversus

Congenital pigmentati

on

Coloboma

Drusen

Hypoplasiaof optic

disk

Anomalies of nerve fibres

Medullated/opaque nerve

fibres

Anomalies of vascular elements

Persistent hyaloidartery

Congenital tortuosity of

retinal vessels

Anomalies of Retina proper

Albinism

Night blindness

Day blindness

Oguchidisease

Retinal cyst

Retinal detachmen

t

Colobomaof fundus

Anomalies of macula

Aplasia

Hypoplasia

coloboma

Coloboma of optic disc• Cause: due to failure of closure of embryonic

fissure

• Occurs in two forms:

Minor coloboma

Fully developed coloboma

Inflammatory disorders of the retinaRetinitis

Non specific

• Acute purulent: occurs as metastatic infections from patients having pyaemia resulting in endopthalmitis or panopthalmitis

• Subacute retinitis of Roth: occurs in patients suffering from SubAcute Bacterial Endocarditis. characterized by multiple superficial retinal hemorraghes,involving posterior part of fundusthey have a white spot in centre.blurred vision is the symptom

Specific

• Bacterial

• Viral

• Mycotic

• parasitic

Retinal vasculitis/Eales’ disease

• Clinical features:

– Sudden appearing

floaters(black spots

infront of the eyes)

– Painless loss of

vision(due to vitreous

hemorrhage)

Inflammation of retinal vessels

Eales’ disease is idiopathic inflammation of peripheral retinal veins

Characterized by recurrent vitreous hemorrahe

Etiology: hypersensitivity reaction to tubercular protein

• Stage of inflammation

• Stage of Ischemia

• Stage of retinal neovascularization

• Stage of sequelae

Clinical stages of the

disease

• Treatment

• Oral corticosteroids

• Laser photo

coagulation

• Vitreo retinal

surgery

(CRAO) CENTRAL RETINAL

ARTERY OCCLUSION

Signs and symptoms• Central retinal

artery occlusions cause sudden, acute, and painless loss of vision in one eye.

Central retinal artery occlusion (CRAO) is a disease of the eye where the flow of blood through the central retinal artery is blocked (occluded). There are several different causes of this occlusion, the most common is carotid artery atherosclerosis.

Fundoscopic exam will show a red lesion, called a

"cherry red spot," with surrounding pale retina (the pale color is caused

by ischemia of the retina)

• The Undersea and Hyperbaric Medical Society lists Central Retinal Artery Occlusion (CRAO) as an approved indication for Hyperbaric Oxygen Therapy.[3] This a treatment for CRAO that is covered by medical insurance in North America. Existing treatments include ocular massage, anterior chamber paracentesis, and inhalation therapy of a mixture of 5% carbon dioxide and 95% oxygen