midterm new Flashcards
Categories of Pupil Abnormalities
❖ ABNORMAL PUPIL SIZE
❖ ABNORMAL PUPIL REACTIONS
❖ ABNORMAL PUPIL SIZE
- Adie’s Tonic Pupil
- Horner’s Syndrome
Parasympathetic block
Adie’s Tonic Pupil
Sympathetic block
Horner’s Syndrome
❖ ABNORMAL PUPIL REACTIONS
- Marcus Gunn Pupil
- Parinaud’s Syndrome
- Argyll Robertson Pupil
- Afferent Defect
Marcus Gunn Pupil
- Central Defect
- Lesion is in interneurons
- Affector->Physiological Connectors->Interneuron->PC->Effector
Parinaud’s Syndrome
also a Central Defect othe than parinuad’s syndrome
Argyll Robertson Pupil
Any lesion located from the retina to the pretectal nucleus is considered a _______________
relative afferent pupillary defect
Any lesion located from preganglionic to postganglionic fiber is considered a _________
relative efferent pupillary defect
➔ Also known as Relative Afferent Pupillary Defect (RAPD) / (APD) or pupillary escape
MARCUS GUNN PUPIL
➔ This indicates damage at or anterior to the LGN (afferent pathway) specifically to the retinal ganglion cells to optic chiasm of one eye
MARCUS GUNN PUPIL
➔ It is caused by a damage that is unilateral or asymmetric (never bilateral) as seen in several retinal diseases (severe), optic nerve disease, lesion behind the eye etc.
MARCUS GUNN PUPIL
◆ Lesions behind the eye such as tumors developed at the optic nerve
◆ Retinal diseases such as DR
◆ Glaucoma (especially unilateral)
◆ Tumors such as pituitary adenoma (usually develops at optic chiasm)
MARCUS GUNN PUPIL
➔ Always unilateral
➔ Defects are always on the retina itself or optic nerve all the way to optic chiasm (so, problems are also always in afferent)
MARCUS GUNN PUPIL
➔ Location: anterior to the LGN
MARCUS GUNN PUPIL
diseases that cause marcus gunn (6)
- CRAO
- CRVO
- BRVO
- Optic Atrophy
- Marked Retinal Detachment
- Asymmetric POAG
Loss of vision due to: (5)
will not produce the Marcus Gunn response
- corneal
- lenticular
- vitreous
- refractive
- emotional causes
An _________ is anything that moves through the blood vessels until it reaches a vessel that is too small to let it pass.
When this happens, the blood flow is stopped by the embolus. An embolus is often a small piece of a blood clot that breaks off (thromboembolus).
embolus
An _____ is often a small piece of a blood clot that breaks off (thromboembolus).
embolus
tell me what you see in a fundus
- In the fundus, a small circle can be found which is the optic disc (always located nasally).
- In the optic disc, the optic nerve is also present. Together with the optic nerve, there are blood vessels that can be seen. And from there, you can observe the thickest blood vessels. And usually, the optic nerve can also be seen together with the CRA and the CRV.
The function of the Central retinal artery
supply oxygen, nutrients, etc to the retina.
if there is clotting (thrombus, embolus, etc), it blocks the flow of blood vessels to enter inside the retina.
CRAO
when CRA is blocked because of clotting, the retina will be affected and there will be a lack of _____
oxygen
CRA is the main supply of _______ to the retina. (2)
nutrients
oxygen
Expect a ________ since retina is damaged (no oxygen/nutrients supply)
Marcus Gunn pupil
In the optic disc, there are main blood vessels that branch out small blood vessels.
These branches are blocked
Branch Retinal Vein Occlusion
Very common in end stage glaucoma (naipit na ang ON so hinay2 nangamatay ang ON fibers)
Optic Atrophy
atrophy means
degenerating/dying
Color of optic disc is ____ in retinal damage
Normal is yellow.
PALE
is marcus gunn present when optic nerve is dead?
yes
it is a serious event, which may result in complete blindness.
Retina, especially 1st and 2nd layers, is like a curtain which can be easily separated if there is a problem.
Marked Retinal Detachment
Common retinal detachments can be experienced to patients with severe:
diabetic retinopathy (end stage)
- Normal color of fundus:
red-orange
- When the retina is detached, some portion of the fundus will still appear red-orange, but the portion where retina is removed appears ____.
grayish
is when you shine a light in the fundus, it reflects back, so red-orange and that is the retina (as it receives the light). So when the retina is detached, there is also no red-orange reflex that can be seen, so it would be pale/grayish.
mechanism of an ophthalmoscopy
Other eye has glaucoma, the other has none.
Asymmetric Primary Open-Angle Glaucoma
type of glaucoma which is asymptomatic or “silent killer”
Open angle
type of glaucoma which is painful, “emergency”
Angle-closure
Glaucoma = increased IOP due to: (2)
A. Increased AH production
B. Blocked drainage / trabecular meshwork
How does the AH flow inside the eye?
The AH originates at the ciliary process
The AH travels to the posterior part of the iris
then passes thru the pupil
all the way to the anterior chamber
The AH will now be drained in the trabecular meshwork.
So if there are problems in the flow, glaucoma occurs.
When there is increased AH production, drainage can’t keep up.
When there is too much AH, it pushes back the vitreous humor until the optic nerve will get stuck
This only happens gradually, not immediately
OPEN ANGLE glaucoma
-Usual sign experienced by px with this type of glaucoma: sudden blackening of vision, then back to normal, black again, then normal..
open angle glaucoma
which part of the eye produces aqueous humor?
ciliary process
division of ciliary body
ciliary process
ciliary body
muscle responsible for accommodation
ciliary muscle
category of glaucoma which is hereditary is nature
primary
category of glaucoma which is acquired
secondary
- Blocked trabecular meshwork
- Most common is due to diabetic retinopathy (especially if px has no drug maintenance, either the eyes or kidneys will be affected)
CLOSE ANGLE GLAUCOMA
Our eyes are sensitive when it comes to changes in the blood
If there is an increase in blood sugar, there will be a __________
Therefore, the retina will not get its nourishment.
decrease in oxygen in the eyes.
WHAT HAPPENS WHEN THERE’S LACK OF OXYGEN IN THE EYES
retina will produce its own blood vessels to have enough supply of blood
different stages of DR: (3)
(1) background,
(2) non-proliferative,
(3) proliferative
Proliferative means
growing
Type of DR where theres new blood vessels are developing in response to low oxygen in the eyes
Proliferative DR
new blood vessels are developing in response to low oxygen in the eyes but these new small blood vessels are very fragile. So they easily rupture. When small blood vessels rupture, it is called ___________.
microaneurysm
what is microaneurysm
when small bv rupture
initial symptom of microaneurysm
blurring of vision
Due to low oxygen of the eyes, the retina produces new blood vessels. To produce these new blood vessels, it also releases ____
therefore, producing small blood vessels, so it proliferates.
vascular endothelial growth factor (VEGF)
So if eyes continue to produce VEGF, from the posterior, it will travel to the anterior. So, as it travels to the anterior, the blood vessels of the iris will also proliferate due to VEGF.
So with an increased VEGF, blood vessels will proliferate until the trabecular meshwork is blocked hence, glaucoma occurs.
This type of angle-closure is specifically called:____
angle-closure neovascularization glaucoma
stimulates the formation of blood vessels
vascular endothelial growth factor
It is the most common type of glaucoma here in the PH
close angle glaucoma
Patient is in pain, an immediate emergency and surgery procedure is needed. But first, to relieve the pain, a mannitol is given to the px.
close angle glaucoma
close angle glaucoma symptoms (3)
dilated pupil
swollen cornea (corneal edema)
pale fundus.
patient has diabetes. Patient neglected it, px got diabetic retinopathy. His DR got worse, it became Proliferative DR, so the blood vessels inside the eyes are growing.
Due to low oxygen because of increased blood sugar, new blood vessels are needed to form in order to supply the retina. However, these new blood vessels are very small and fragile.
Therefore, it easily ruptures (microaneurysm). When the retina forms new blood vessels, it also releases a chemical called VEGF. This will then travel to the anterior chamber where the blood vessels of the iris will also proliferate causing the trabecular meshwork to be blocked. When TM is blocked, AH cannot be drained causing angle-closure neovascularization glaucoma.
Marcus Gunn Pupil – Method of Diagnosis
Method of diagnosis: Swinging Flashlight Test
In an affected eye with Marcus Gunn, the consensual response is greater than the direct response.
A. When light is directed into the right eye → (normal direct and consensual response of that eye) → both eyes are smaller
B. When light is directed into the left eye → (normal direct and consensual response of that eye) → both eyes are smaller
C. Swinging the light back to the other eye causes normal pupil constriction.
Patient with No Pupillary Defect
A. When light is directed into the normal eye → (normal direct and consensual response of that eye) → both eyes are smaller
B. When light is directed into the affected eye → both pupils are larger (slightly dilate)
C. Swinging the light back to the other eyes causes normal pupil constriction.
Patient with Marcus Gunn