optha-retina, glaucoma Flashcards
Only non transparent portion of retina
Blood columns and pigment epithelium
Innermost layer of the eye
Retina
Posteriorly, retina converges towards the ____ to form intra ocular portion of _____
Posteriorly, retina converges towards the OPTIC DISK to form intra ocular portion of OPTIC NERVE
The anterior or peripheral portion of the retina is marked by ____ where retina is transformed into nonpigmented epith of ciliary body
The anterior or peripheral portion of the retina is marked by ORA SERRATA where retina is transformed into nonpigmented epith of ciliary body
The retina is firmly attached to 2 portions
Ora serrata
Optic disk
Layers of retina
(From outer to inner)
- Pigment epith
- Rods and cones
- External limiting membrane
- Outer nuclear layer
- Outer flexiform layer
- Inner nuclear layer
- Inner flexiform layer
- Ganglion cell layer
- Nerve fiber layer
- Internal limiting membrane
Pigment epith is derived from
Outer layer of optic cup
If pigment epith is derived from outer layer of optic cup, then the rest of the retina Comes from
Inner Layer
Where does retinal detachment occur?
Between pigment epith and the rest of the retina, which has embryological basis.
The pigment epith is composed of single layer of ____ cells! with micro villi projecting into the interspace between outer segments of rods and cones.
Polygonal cells
Layer which is source of metabolic enzymes, as well as vit.A needed by visual cells, which is imp in the phagocytosis of degenerated fragments of outer segments.
Pigment epith
Rods and cones layer is composed of outer and inner segments. What segment can you find the light-sensitive photo chemicals?
Outer segment
Has transverse disk which contain the visual pigment concerned in photochemistry of visual process converting light energy into chemical energy of nerve impulse.
Rods and cones layer is composed of outer and inner segments. What segment contains usual cyto and cytoplasmic organelles esp mito which amplifies the weak impulse into a transmitted current?
Inner segment
Which is connected to the outer by a constriction containing the cilia, which thought to transmit electrical impulse to the finely granular inner segment
Layer of retina which is a fenestrations membrane composed of terminal bars
External limiting membrane
External limiting membrane is Formed by junctional attachment between..
membranes of Muller cells and the inner segment of photoreceptors
Layer of retina which is composed of the nuclei of the photoreceptors.
Outer nuclear layer
Layer of retina which constituted by the axons of photoreceptors and the connecting dendrites of bipolar cells
Outer flexiform layer
In what region does the bipolar cells and other elements of inner layer of retina are pushed to the sides, where the axons and dendrites in outer plexiform layer take an oblique or tangential course.
In region of fovea
In region of fovea, the bipolar cells and other elements of inner layer of retina are pushed to the sides, the axons and dendrites in outer plexiform layer take an oblique or tangential course. This unique portion of outer plexiform is called..
Nerve fiber layer of Henle
Layer of retina which consists if nuclei if several cells, namely bipolar cells, Muller’s cells, horizontal cells, and amacrine cells.
Inner nuclear layer
Layer of retina which is composed of axons of bipolar cells and dendrites of ganglion cells.
Inner plexiform layer
Layer of retina in which ganglion cells usually form a monocellular layer throughout most of the retina
Ganglion cell layer
Layer of retina where the axons of the ganglion cells converge toward posterior pole of the eye to eventually from the optic nerve.
Nerve fiber layer
Layer of retina which is the cuticular derivative of Muller’s cells and serves to delineate the retina from the overlying vitreous.
Internal limiting membrane
Bld supply of retina
Central retinal artery and vein which enters the eye thru optic disk
First branch of ophthalmic artery
Central retinal artery
As the retinal artery enters the eye, it loses its ____ , and the medial muscular coat becomes ____.
As the retinal artery enters the eye, it loses its INTERNAL ELASTIC LAMINA and the medial muscular coat becomes INCOMPLETE.
How many capillary networks are there in the retina? Where is It located?
Two. One in nerve fiber layer and one in inner nuclear layer.
They are closely interconnected.
Retinal capillaries contains ___ that are located in the basement membrane.
Mural cells
The artery and vein have a common adventitial sheath at their crossings, an important factor in the production of AV crossing changes in what diseases?
Arteriosclerotic and hypertensive retinopathies
Photoreceptors which func at low level of illumination or night vision (scotopic vision).
Rods
Photoreceptors which func at high level of illumination or daytime vision (photopic vision).
Cones
Photoreceptors for color vision
Cones
Center of acute vision
Fovea centralis
Rods/cones are concentrated in Fovea centralis
Cones
Main cells in retinal periphery
Rods
Photoreceptors concerned with peripheral vision
Rods
The retina is dependent on a continuous supply of ___ for its metabolism.
Glucose
Cells the serves as the storehouse of glucose in the form of glycogen
Muller’s cells
The retina gets its bld supply from 2 sources
choriocapillaries supply the outer layer
Retinal arteries supply the inner layer
Principal symptom of retinal patho
Visual disturbance
Visual disturbance may be manifested as..
Visual blurring Photopsia Sector visual field defect Disturbance of image shape or size Nyctalopia
Visual loss or impairment may involve (central/peripheral vision) if macula is involved.
Central vision
Visual loss or impairment may involve (central/peripheral vision) if extra macular area (esp rods) is involved.
Peripheral vision
Seeing flashes of light
Photopsia
It is caused by any stimulus on the eye which results in only one retinal response, and that is seeing light.
Photopsia
Photopsia may be experienced in ___ where the retina is mechanically stimulated as it floats or moves in the vitreous.
Retinal detachment
Photopsia may be experienced in ___ which causes traction in the retina (Moore’s lightning streaks).
Vitreous detachment
Actual loss of a part of the field of vision or a sensation of a curtain or a fog covering the involved portions of the field of vision
Sector visual field defect
Some retinal condi which can produces sector visual field defect
Partial retinal detachment
Large retinal hemorrhage
Branch occlusion of retinal vessels
Caused by disturbance in the alignments and position of the visual cells, esp macular area as in macular edema, central serous retinopathy or flat retinal detachment
Disturbance of image shape or size
Distorted image
Metamorphopsia
Large image
Macropsia
Small image
Micropsia
Refers to impairment of vision at night or in dim illumination and is present mainly in disturbances of rod func as in pigmentary degeneration of retina and vit A deficiency
Nyctalopia
Usual loos of arterial obstruction
Emboli from a cardiac thrombus
Retina artery is very much constricted Optic disc is pale Rest of eye ground is white (due to coag necrosis) Cherry red spot Box car appearance
Crao
Treatment for crao
Dilators - paracenthesis, inhalation of co2 (carbogen)
Drugs - amyl nitrate inhalation, retrobulbar acetylcholine, prescoline
Common cause of CRVO in elder
Endothelial proliferation
Common cause of CRVO in young
Phlebitis
Venous engorgement
Retinal hemorrhage
Hyperemic disk with blurring of margin
Hotdog catsup appearance
CRVO
Common complication of CRVO
Glaucoma (3 mos after onset) has rubeosis iridis
Retinal edema in hypertensive retinopathy is seen as shining reflex from the retinal surface not unlike a wet surface and is called
Retinal sheen
Grading in hypertensive retinopathy
- Narrowing of arteries to 3/4 to 1/2 of corres vein with occasional focal constriction of terminal arterioles
- Narrowing of arteries to 1/2 to 1/3 of corres vein with several focal constriction of terminal arterioles
- Grade 2 + cotton wool exudates with flame shaped hemo
- Grade 3 + mild to mod edema of disk
In arteriosclerotic retinopathy, a Whitish plaque of lipid seen in the wall of retinal artery
Atherosclerosis
Lipoidal infiltration of white streak at side of blood column is seen and called
Pipe stem sheathing (vascular sheathing)
In arteriosclerosis, when the median streak completely covers the entire bld column, the artery is called
Copper wire artery
In arteriosclerosis, when the sclerosis reaches the advance stage abs reflects back all the light falling on its surface, the artery is called
Silver wire artery
This is an early stage of silver wire artery where the artery is seen as a solid white cord with no bld column showing through.
Pipe stem sheathing
Grading of severity in arteriosclerosis
- Slight widening of median reflex with slight compression
- More widening , with more marks of compression
- Copper wire artery
- Silver wire artery
Edema of macular region
Central serous retinopathy
Retinal detachment that is always asso with break in retina
Primary retinal detachment
Retinal detachment due to disease process of retina or the vitreous and choroid
Secondary retinal detachment
Most common symptom of retinal detachment
Photopsia
Elevated retina
Grayish retina
Retinal vessels appear constricted and darker
Retinal detachment
Most common intraocular tumor
Retinoblastoma
Cats eye reflex
Leucocoria
Stage of retinoblastoma with soapy white mass in retina
Intraocular stage
Stage of retinoblastoma with increased iop, ocular congestion nod corneal edema and vitreous filled with tumor mass
Glaucomatous stage
Stage of retinoblastoma with tumor extending out of eyes into orbit via ocular emissaria or thru optic nerve
Extra ocular stage
Retinoblastoma metastasize to __ via
Long bone via hematogenous spread
In Glaucomatous stage of retinoblastoma, what is the only resor it save the life of the pt
Enucleation
Glaucoma produces irreversible blindness
True
Iop regarded as suspect for glaucoma
21mmHg
Regulation of IOP by
Anterior segment of eye
Increased iop in glaucoma is due to
Abnormal aqueous outflow
Rarely due to over production
Most rarel py due to nice venous back pressure
Effect of iop is ultimately manifested in
Optic disk
Disturbance to floe of protoplasm contributes to glaucoma
True
2 sources of symptoms of glaucoma
Increased iop
Disturbance of optic nerve func
Acute or chronic glaucoma:
Severe ocular pain, sudden diminution if vision, seeing haloes around light, ciliary injection, Lacrimation, pupillary dilation
Acute glaucoma
Acute/chronic glaucoma:
Gradual closure of angle and gradual increase in iop, symptoms may be absent
Chronic glaucoma
Iop increased because aqueous could not flow to trabecular mesh work due to apposition of iris to the anterior chamber angle
Primary angle closure glaucoma
This disease arises because if an inherited a atomic defect that causes a shallow anterior chamber
Primary angle closure glaucoma
Treatment of choice for primary angle closure glaucoma
Surgery
Principle of management of primary angle closure glaucoma
Lower iop
Analgesic
Referral to ophthalmologist
Closure of angle brought about by condi in eye that causes the iris to move towards the mesh work. (Eg exaggeration of pupillary block such as uveitis, lens dislocation, bulging hyaloid face)
Secondary angle closure glaucoma
The treatment of Secondary angle closure glaucoma is directed to ocular condition that gives rise to it
Principle of therapy is the same as primary angle closure type
Aqueous has access to the anterior chamber angle all the time because there is no ore existing ocular or systemic disease that can be tagged as causative agent. It is symptom-free chronic, slowly progressive condi.
Primary open angle glaucoma
Treatment of primary open angle glaucoma
Medical
Drugs used in primary open angle glaucoma
- Miotics - increase outflow
- Carbonic anhydrase inhibitors - decrease aqueous production
- Epinephrine - enhance exit of aqueous
Treatment of infantile glaucoma
Surgical (goniotomy)
S&s of infantile glaucoma
Lacrimation Blepharospasm Photophobia Corneal enlargement Glaucomatous cuppping
Glaucoma asso with hereditary or familial disease are not always present at birth
True
Glaucoma asso with hereditary disease, a syndrome of arachnodectyly, cardiac anomalies, lens subluxation
Marfan’s syndrome
Glaucoma asso with hereditary disease, a syndrome of corneal Arcus (post embryotoxon), ectopia, polycoria, hypoplasia of anterior iris.
Axenfeld syndrome