Disorders of the Retina Flashcards
The retina is a direct extension of ________
The nervous system.
the retina does what so the brain can “visualize”
Transforms the image focused by the anterior ocular structures into impulses.
Why do the vessels in the retina provide such a unique view?
- they are so small, they are representative of what is happening in other vessels in the body.
- very telling for the health of a patient
- only place where an examiner can look directly at blood vessels
- vascular diseases appear in these small vessels first
What is in the center of the macula?
Fovea centralis
True or False Veins typically appear larger and darker when viewed in the eye.
True!
Arteries are more pale and thinner appearing.
What are the 3 basic forms of diabetic retinopathy?
- Proliferative diabetic retinopathy
- diabetic macular edema
- Ishchemia of the macula
Can all 3 forms of diabetic retinopathy lead to blindness?
Yes, they all lead to blindness
Proliferative Diabetic Retinopathy results from _________?
Retinal Ischemia
What do ischemic retinal tissues release in Proliferative Diabetic Retinopathy?
Angiogenic Factors
What happens when Angiogenic fibers are released?
neovascularization
What is the big deal w these neovascularized vessels growing in the vitreous gel?
Normal movement and traction can shear these fragile new vessels–> leads to hemorrhaging and cloudy vision
What happens when contraction is placed on this fibrous clot?
Puts traction on the retina and can cause retinal detachment from choroid.
What are the symptoms of Proliferative Diabetic Retinopathy?
- may be asymptomatic
- vision may decrease slowly or suddenly
- excessive floaters occur w a hemorrhage= “showers”
- Blind spots can occur (scotomata)
What are the signs of Proliferative Diabetic Retinopathy?
- Neovasculalization* of fine lacy blood vesells seen on the optic nerve, retina, or surface of the iris.
- cotton wools spots on retina ( whitish lesions with fluffy hazy appearing borders)
- pre-retinal hemorrhages (boat shaped hemorrhages)
- vitreous hemorrhages–> cause loss of normal red reflex
So if you see boat shaped hemorrhages floating around in cotton wooly spots whats the first thought in your mind?
Proliferative Diabetic Retinopathy!!!
What labs tests should be performed for Proliferative Diabetic Retinopathy?
-lab tests to dx diabetes
fasting blood sugar, HBA1c
What is the Tx for Proliferative Diabetic Retinopathy?
- Control diabetes. Tight glycemic control decreases the profession of diabetic retinopathy, nephropathy, and neuropathy.
- Retinal Laser photocoagulation
- newly dx’d DM type II need optho consult
Diabetic Macular Edema can lead to what?
micro-aneurysms, which leak intravascular fluid into the retina.
What happens when this fluid is leaked from the micro-aneurysms?
May accumulate in the fovea–> leads to decreases central vision
What are the symptoms of Diabetic Macular Edema?
- may be asymptomatic
- vision may be diminished unilaterally or bilaterally (remember… from the leakage)
what signs will you see when a pt presents with Diabetic Macular Edema?
- slight opacification of the macula (from the edema fluid)
- micro-aneurysms (tiny blisters/pimples)
- Hard exudates (yellow lesions w/ discrete borders)
What is the tx fro Diabetic Macular Edema?
Refer to ophthalmologist
What do normal retinal vasculature blood vessel walls look like?
So thin they are invisible. really only see the blood, not the walls that hold it.
What does chronic hypertension do to the vessel walls?
Thickened vessel walls and an associated narrowing of the vessel lumen
What is the Hallmark sign of Hypertensive Retinopathy?
Diffuse arteriolar narrowing
What is the normal Artery to Vein Ratio?
What is the A:V ratio w Hypertensive Retinopathy?
- normal= 2:3
- Hypertensive Retinopathy=1:3 or even 1:4…. arteries VERY narrow.
Back in the day before brighter halogen light sources were around what color would the vessel wall appear?
Yellowish–> “copper wiring” (quote unquote)
-Silver wiring
What are the symptoms of Hypertensive Retinopathy?
- vision may be normal, or slightly blurred, or suddenly decreased (vision can be anything really…)
- scotomata (blind spot)
- double vision
An an examiner what signs will you see with Hypertensive Retinopathy?
- Arteriolar narrowing
- AV nicking
- Sclerotic Vessels
- cotton wool spots
What is AV nicking anyways?
Arterial pressure is too great, so when it crosses over a vein it obliterates the vein directly below it. Further down the vein does return to its normal caliber.
TX for Hypertensive Retinopathy?
Bad news….
- No specific ophthalmic tx.
- Treat underlying HTN
- may have to refer to ophthalmologist
What is the cause of Retinal Artery Occlusion?
embolus
What may Retinal Artery Occlusion be preceded by?
amaurosis fugax=”a curtain descending” or cloudy vision
-transient monocular blindness related to emboli
Amaurosis fugax can also be a warning sign of what?
Impending cerebral stroke
What signs will be found on the physical exam of a patient w/ Retinal Artery Occlusion?
- profound vision loss (transient).
- patient may only perceive hand motion or light
- whitening of retina on ophthalmoscopic exam
- Cherry red spot in macula
If you see a cherry red spot on the macula and believe it to be Retinal Artery Occlusion, would you refer this patient?
Yes this is an ophthalmological emergency!
What is retinal vein occlusion associated with?
Hypertension and blood dyscrasias
note: dyscrasias–> disease/disorder associated w blood
retinal vein occlusion is a result of a________?
Thrombosis is the RV
What are the physical exam findings of retinal vein occlusion?
- retinal hemorrhages
- dilated tortuous veins
T/F retinal vein occlusion is an Ophthalmological emergency.
True!
make that call if you see those cherry red spots on the macula and believe it to beretinal vein occlusion!
What is Retinitis pigmentosa?
Inherited dz=retina degenerates
What pt population is Macular Degeneration typically seen in?
Elderly patients (>60)
What other name is Macular Degeneration sometimes called?
Exudative macular degeneration
What do patients with Macular Degeneration typically complain of?
- Metamorphosia, things that should have straight lines appear wavy*
- visual loss that can occur over days or longer
On the physical exam for a pt with Macular Degeneration you will see
-retinal hemorrhage- typically in the macular region
If you suspect a pt has Macular Degeneration should you refer?
Yes immediate referral to ophthalmology
What is Ischemic Optic Neuropathy most often associated with?
- giant cell arteritis/temporal arteritis
- also hypertension and diabetes (pts>40)
What is the common age for Ischemic Optic Neuropathy ?
> 60
Describe the visual loss for Ischemic Optic Neuropathy
- sudden
- monocular on affected side
What do pts typically complain of w Ischemic Optic Neuropathy
- jaw pain
- scalp tenderness
- neck pain
- weight loss
What will your physical exam reveal of a pt w Ischemic Optic Neuropathy?
- optic nerve=swollen
- afferent pupil (marcus-Gunn pupil=+ swinging flashlight sign)
Ischemic Optic Neuropathy ________ ophthalmology referral
Immediate
Optic Neuritis is associated with______?
Multiple Sclerosis
What are the demographic features of MS? And thus Optic neuritis?
- ages 15-45
- Women>men
- Colder latitudes>tropical latitudes
Visual loss for Optic neuritis occurs over __________ days
several
for Optic neuritis occasionally there will associated complaints of
- painful eye movement
- periorbital pain but ≠ocular pain
What are the physical exam findings for Optic neuritis?
- may= afferent pupil defect
- 2/3 pts= normal optic disc on funduscopic e
- 1/3= optic disc edema (blurring of optic disc margin)
What referral should you make for Optic neuritis?
- refer to neuro of MS suspected
- ophthalmology
Tx for Optic neuritis?
IV corticosteroids
Atrophic Macular Degeneration is commonly seen in patients >______yo
60, and may be associated w family hx
Exam findings for Atrophic Macular Degeneration?
- loss of central vision
- may see Drusen(hyaline nodules) on funduscopic exam
- later in dz= retinal atrphy/retinal scar
What causes retinal detachment?
- fluid separates the retina from retinal epithelium
- retina separates from vitreous
- Tractional Detachment- scar tissue in vitreous gel contracts–>pulls retina towards vitreous (commonly from virtual hemorrhage from proliferative diabetic retinopathy)
What are the symptoms of retinal detachment?
- flashes (photopsia)
- floaters
- visual filed loss (wherever retina is detached)
- metamorphosia (wavy/distorted lines)
- decreased vision
What are the signs of Retinal detachment?
-marcus gunn pupil
unilateral visual field loss (when one eye is closed, double vision remains when the bad eye is opened)
-Retinal ruggae (ripples in pond)
Work up for Retinal Detachment?
- difficult to dx on physical exam
- hx is the real guide
- look at red reflex on both eyes several ft away (note differences)
Tx for retinal Detachment?
- immediate ophthalmological consultation
- surgical intervention
What happens if retinal detachment is not corrected immediately?
will result in permanent visual loss in the affected eye
choroditis (etiology/pathology)
- inflam of choroid layer
- acute onset
- infx
choroiditis (presentation)
- blurry, impaired vision in 1 eye
- photophobia
- red eye
- decreased VA
- injection of eye
choroiditis (tx)
- tx underlying cause
- steroids in non-infectious
T/F: Newly diagnosed DM type II need optho consult.
- true, for proliferative diabetic retinopathy
