LECTURE 16...did not feel like studying pharm

1. Given the clinical presentation of any patient with acute visual loss, be able to recognize the following diagnoses:

a. Migraine-induced visual loss
Disturbance in vision in both eyes
Develop into scotomata
Edges of flashing or zigzag lines
Tunnel vision common
Sympt last 15-20mins and followed by headache, photophobia, nausea.
Vision is recovered.

b. Retinal detachment
Heralded by flashing lights and floaters (black spots that drift about)
Then there is a curtain or shade of darkness over vision in one eye
Visual loss begins in periphery and moves centrally.
If severeàafferent papillary defect develops in involved eye.
SURGERY TO RETACH retina.

c. Amaurosis fugax
painless
transient
monocular vison loss
pts over 50.
“Curtain coming down over vision” which may affect whole visual field, or only the superior or inferior ones.
Attack completes 30secs and may resolve within 10 mins
Increase risk of stroke.

d. Optic neuritis
infl of optic nerve due to MS, infection, vasculitis.
Young patients 20-45
Sudden loss of vision, unilateral
Pain on eye movement
Vision loss becomes maximal over 3-7 days and then stabilizes
May see afferent papillary defect
Can be retrobulbar
Lesion is further posterior to the nerve head.
Vision improves 6-8 wks
Optic nerve becomes ple wks to months after attackàoptic atrophy
MRI if MS for Rx.

e. Arteritic and non-arteritic ischemic optic neuropathy

Non-arteritic: 50 to 70 years.
painless sudden loss of vision in one eye.
entire VF or just the upper or lower half of the VF (hemi- altitudinal defect).
Vision loss is variable and may be minimal (20/30 to 20/40) or severe (counting fingers).
Visual loss remains stable with no recovery.
Initially, the optic disc is pale and swollen with occasional small flame hemorrhages
Optic disc swelling resolves in 4-8 weeks, and optic atrophy becomes evident.

Arteritic:
70 to 90 years of age.
Visual loss is often severe, even to no light perception.
Fever, weight loss, general malaise, myalgias, temporal headache, jaw claudication, and tenderness over the temporal arteries.
High erythrocyte sedimentation rate (ESR)
Generally over 60 mm/hr and usually 90 to 110 mm/hr.
This is a true emergency requiring prompt diagnosis and treatment.

f. Papilledema
swelling of the optic discs due to increased intracranial pressure.
bilateral and usually asymmetric.
must be considered urgent, and the patient should be assumed to have an intracranial mass lesion until proven otherwise. Neuroimaging is mandatory.
If CT or MRI is negative, then further work up including lumbar puncture is necessary to rule out idiopathic intracranial hypertension (pseudotumor cerebri), CSF inflammation, infection, or neoplasm.
in its early stages is frequently asymptomatic. P
atients may complain of transient loss of vision lasting seconds ("transient obscurations of vision").
Initially VF exam reveals only a large blind spot
Treatment of papilledema depends on the cause.

2. Given the clinical presentation of any patient with chronic visual loss, be able to recognize:
a. Refractive errors
presbyopia occurs in later middle age as the eye loses its ability to accommodate.
Both eyes are affected, usually symmetrically.
The patient has trouble focusing at near and tends to hold targets further away
This is easily corrected with reading glasses or bifocals.
b. Cataracts
Opacity of the lens, usually associated with aging
The pupil may appear cloudy, white, or yellowish.
Patient complains of slowly progressive visual loss, glare, or washed-out colors.
Surgical extraction is considered when the patient's daily activities are affected by the cataractous visual loss.
A decreased red reflex may be appreciated when viewed through the direct ophthalmoscope held at a distance.

c. Glaucoma
damage to the optic nerve and visual field by elevated intraocular pressure
Open-angle glaucoma is more common in the elderly and results in painless progressive loss and contraction of peripheral visual field, sparing the central field until late in the disease.
Intraocular pressure increases because of decreased outflow of aqueous through the trabecular meshwork of the eye,
Increased pressure damages the retinal axons as they exit the eye at the optic disc
the optic disc may show cupping (an increased cup:disc ratio) or notching of the neural rim of the disc.
A cup larger than one half the size of the disc (cup:disc ratio >0.5) or asymmetry of the cup:disc ratios between the eyes should raise the suspicion of glaucomatous damage.
Treatment by an ophthalmologist may include medical, laser, or surgical intervention.

3. Given the clinical presentation of any patient with visual loss, be able to recognize when referral to an ophthalmologist is necessary for diagnosis.

TO BE ANNOUNCED

4. Given a patient with the chiasmal syndrome, be able to list the most common causes and the appropriate evaluation
caused by compression of the chiasm by a tumor, aneurysm, or other mass lesion.
One or both optic nerves or tracts are often involved.
This presents as slowly progressive visual loss in any age group.
Symptoms may range from none, to mild blurring in one or both eyes, to severe loss of vision.
The visual acuity may be normal or abnormal. T
VFs often demonstrate bitemporal VF loss respecting the vertical meridian (bitemporal hemianopia),
The optic discs may be normal or show optic atrophy.
MRI, are mandatory.