Ocular Disorders: Posterior Flashcards
Most common cause of reversible blindness worldwide
Cataracts
Cataracts
Opacification of the intraocular lens resulting in vision changes
Most common cause of cataracts
age-related changes in crystalline lens
Other causes of cataracts
- diabetes mellitus
- galactosemia
- hypocalcemia
- Radiation
- Trauma
What is attenuation?
(↓ force/effect) of light
Cataracts pathophysiology
- Loss of optical clarity
- Morphological changes
- Building up a diffusion barrier to
nucleus coloration/clouding of lens - Biochemistry
- ↓ glutathione (antioxidant) levels
- Formation of advanced glycolated
end products - Loss of alpha-crystallin chaperone
Cataracts clinical presentation
- Often detected during routine eye
exam in asymptomatic patients - May report gradual painless loss
of vision at distance - Typically bilateral, but can be
asymmetrical
Diagnosis of cataracts
- Most diagnosed during rouXne ophthalmoscopic exam in asymptomaXc paXents
- Suspect in older paXents with progressive ↓ vision or other S/S
- Diagnosis confirmed by comprehensive eye exam (Ophthalmology)
Cataracts management
- Management of symptomatic cataract is primarily surgical
- Nonsurgical management
- Prescribe eyeglasses (if appropriate)
- Counsel patients about cataract-related visual symptoms
- Provide reassurance about cause of visual impairment
Age-related Macular Degeneration (AMD)
Progressive chronic retinal disease of aging eye(s), characterized by:
- Drusen (focal yellowish deposits of acellular, polymorphous debris)
- Geographic atrophy of retinal pigment epithelium
- Neovascularization leading to visual impairmen
Age-related Macular Degenera4on (AMD) Pathogenesis
- Cause unknown
- Drusen forms below retinal pigment
epithelium & Bruch’s membrane - Geographic atrophy begins to
manifest as retinal pigment
epithelium changes
AMD Clinical presentation
Incidental finding <——-> Sudden central visual distortion
* May report ↓ vision, flashes of light (photopsia), or difficulties with light
adaptation
AMD diagnosis
- Comprehensive exam, including visual acuity & Amsler grid
- Dilated fundoscopic exam with stereoscopic biomicroscopic exam of the macula
- presence of few medium (63-124 micrometers) Drusen (early AMD)
- retinal hyperpigmentation or hypopigmentation
- retinal atrophy
- Optical coherence tomography
___ is #1 severe, irreversible vision impairment in developed countries
AMD
AMD Management
- Smoking cessation (if applicable)
- Early AMD → obervation
- Intermidiate/Advanced AMD → antioxidant vitamin (carotenoids, vitamins C & E) & mineral supplements (selenium & zinc)
1st Line treatment for AMD
Neovascular AMD → Intravitreal injection of antivascular endotheial growth factor antibodies
Complications & Referral Considerations for AMD
- Blindness
- ↑ risk for depression, hip fracture, & nursing home placement
- Charles Bonnet syndrome
- ↑ mortality in patients aged 49-75 years
Glaucoma: Two types
Acute angle closure: Primary glaucoma in which contact of the iris with the peripheral cornea excludes aqueous humor from the
trabecular drainage meshwork.
Chronic open angle: Primary glaucoma in which the aqueous humor has free access to the trabecular meshwork.
Glaucoma – Angle Closure clinical presentation
- Asymptomatic early
- Symptomatic: >90% of attacks are unilateral
- Severe ocular pain
- Sudden vision loss
- Blurred vision
- Halos around lights
- Headache
- Eye redness
- Nausea & vomiting (if IOP high)
Glaucoma – Angle Closure physical exam
- Structural assessment of optic cup
- Visual field loss in severe cases
- More diffuse with angle-closure glaucoma
- Slit-lamp biomicroscopy
*** Tonometry
Diagnostic Criteria for Glaucoma – Angle Closure
≥ 2 symptoms
1. ocular or periocular pain
2. nausea &/or vomiting
3. Hx of intermittent blurring of
vision w/ haloes
Glaucoma – Open Angle clinical presentation
- Asymptomatic early
- Symptomatic
- Ocular burning/smarting/stinging/soreness
- ocular tiredness
- blurry/dim vision
- Eye foreign body sensation
- visual difficulty in daylight &/or darkness
- halos around lights
- Ask about use of steroids
Left untreated open angle
glaucoma will lead to
_____
permanent blindness
Glaucoma results in ____ as the central cup becomes enlarged
“cupping”
Glaucoma – Angle Closure Management
Laser trabeculoplasty is the ini7al therapy in selected patients or alternative for patients who can/will not use medications reliably
Glaucoma – Open Angle Management
- Long-term medications (↓ IOP) delay
visual progression in pts with primary
open-angle glaucoma or ocular
hypertension - Topical medications
- Beta-blockers
- Prostaglandin analogs
- Parasympathomimetic agents
- Alpha-adrenergic agonists
- Systemic carbonic anhydrase
inhibitors
1 cause of preventable
blindness in US adults 20-74 yo
Diabetic Retinopathy
Diabetic Retinopathy Clinical persentation
- Often Asymptomatic!
- Blurred or double vision
- ↓ field of vision
- Seeing dark spots
- Pressure or pain in eyes
- ↓ vision in dim light
- Sudden blindness (rarre)
Advanced Hypertensive Retinopathy findings on exam
- Flame hemorrhages
- Arteriovenous nicking [a small artery
(arteriole) is seen crossing a small vein
(venule), which results in the
compression of the vein with bulging on
either side of the crossing] - Cotton-wool spots
Diagnosis of Diabetic Retinopathy
- Funduscopic Exam Findings (direct ophthalmoscopy)
- Ideally done during routine, annual, asymptomatic screening
_____ are generally the 1st clinical sign in the early-stages of Diabetic Retinopathy
Microaneurysms
Central Retinal Artery Occlusion
blockage of the arterial supply to the retina
leading to retinal ischemia or infarction & transient or permanent vision loss.
Central Retinal Artery Occlusion most common cause
Embolism
Central Retinal Artery Occlusion common clinical presentation
- Sudden painless, monocular vision
loss or degradation
“a veil/curtain/shade suddenly
coming down over my eye”
Retinal opacity, or whitening, with cherry red spot is earliest sign for ____
Central Retinal Artery Occlusion
Central Retinal Artery Occlusion Management
- The prognosis for visual recovery is related directly to the promptness in
treatment; thus… - Rapid transport to the ED is essential!
____ constitute the
second most common retinal
vascular disorder.
CRVO & Branch Retinal Vein
Occlusion (BRVO)
Central Retinal Vein Occlusion
Backup of the blood in the re?nal venous system &
increased resistance to venous blood flow 2° thromboembolism
Leading cause of visual loss in both
ischemic & nonischemic CRVO
- Ischemic damage to the retina may
stimulate ↑ production of vascular
endothelial growth factor (VEGF) in the
vitreous cavity → neovascularization of
the posterior & anterior segment - VEGF causes capillary leakage → macular
edema
Central Retinal Vein Occlusion Diagnosis
Visual acuity: Variable → one of the
important indicators of prognosis
- Retinal hemorrhages may present in all 4 quadrants.
- can be superficial, dot & blot, &/or deep.
- may be seen in the peripheral fundus only.
- mild to severe, covering the whole fundus
- “Blood & Thunder” appearance
Re&nal Detachment
Separation of neurosensory retina from underlying retinal pigment epithelium
Re&nal Detachment most common cause
Rhegmatogenous detachment → entry
of liquid vitreous into subretinal space
through a retinal break
Retinal Detachment - Exudative detachment
subretinal fluid accumulates & causes detachment without any corresponding break in the retina
* Tumor growth or inflammation
Retinal Detachment - Traditional attachment
centripetal mechanical forces on retina, usually mediated by fibrotic tissue & scarring from previous disease
* Diabetic retinopathy
* sickle cell disease
* penetrating trauma
Retinal Detachment exam findings
- Marcus-Gunn pupil
- Intraocular pressure measurement in both eyes
- Relative hypotony of >4-5 mm Hg less tobacco dust
(Shafer sign) than the fellow eye is common] - Described as a dim “shadow” or “curtain”
Retinal Detachment is a ______
Surgical Emergency
Optic Neuritis
occurs when inflamma?on damages the optic nerve
Periocular pain can occur in >90% of patients who have ____
Optic Neuritis
Optic Neuritis Clinical Presentation
- May present with visual deteriora?on during exercise or elevated temperature
- Uhthoff phenomena
Anterior Ischemic Optic Neuropathy
Sudden loss of vision due to a decreased or interrupted blood flow to the eye’s op?c nerve
Most common cause of acute op?c neuropathy in older age groups
Anterior Ischemic Op*c Neuropathy
Amaurosis Fugax
Amaurosis “dark” & Fugax “flee?ng” – Transient loss of vision
