Flashcards in Ophthamology: Acute Visual Loss Deck (24):
What is Iris Synechia?
Condition where the iris attaches either to the lens (posterior) or the cornea (anterior). Both can lead to glaucoma.
There are few emergent situation in ophthalmology. What is one caused by corneal edema and how is it treated?
Acute Angle Closure Glaucoma: fixed pupil, red eyes, INTENSE PAIN often leading to nausea, very high Intra Ocular Pressure (IOP).
Treat with laser iridotomy
-punch a whole in the iris with a laser to allow drainage of aqueous humor thru iris.
What is a hyphema?
Blood in the anterior chamber.
Most are caused by trauma, however, some can be caused by the presence of abnormal blood vessels in the iris. These vessels can be a result of diabetes, tumors, or surgery.
What is Rubeosis?
Spontaneous neovascularization of the iris. Can often lead to hyphema.
What is hypopion?
Pus in the anterior chamber usually resulting from infection.
How can blood sugar spikes or diabetes cause cataracts?
Continuous high blood sugar causes accumulation of glucose in the blood which makes its way to the lens in the eye. Enzymes convert the glucose to sorbitol which can accumulate in the lens and increase osmolarity which attracts water.
Once the lens absorbs enough water, the sugar will crystallize in the lens and make it more opaque.
Common complaint with retinal detachment.
Flashers and floaters (this condition is often painless)
What type of test may show up positive during an eye exam in a patient with a detached retina.
-afferent pupillary defect or Marcus Gunn test.
Most common cause of blindness in developed countries and the mechanism.
Wet Macular Degeneration
-caused by neovasularization and leaky vessels in the macula
What is metamorphosia?
A Combination Of Squeezing And Spreading of the cones cause an overall distortion of the image (visual field). Occurs in macular degernation and some retinal pathology.
What is amaurosis fugax?
Transient vision loss that is restored shortly. Usually occurs due to a retinal vascular occlusion like a carotid embolus.
Manifestation of a Central Retinal Artery Occlusion (CRAO) that can be observed in ophthalmoscopy.
Cherry Red Macula
-macula has a superficial vascular supply that can be observed if blood pressure increases.
(also seen in Tay Sachs)
What is important to remember when dealing with any type of retinal artery occlusion?
There is usually an underlying condition that caused the occlusion and should be identified and treated. Retinal artery occlusion have a poor 5 year prognosis (50%).
What creates a "blood and thunder fundus" when viewing the retina?
Retinal Vein Occlusion
-these look really bad but usually have a great prognosis with full visual recovery.
What can be found on physical exam in patients with optic neuritis?
*Pain with eye movement
Monocular enlarged CN II
(however, if it is retrobulbar it will not be visible)
If the Optic Neuritis is caused by MS, what is the treatment?
1. IV prednisolone for 45 minutes
2. Oral steroids
Main difference between papillitis and papilledema.
Papilledema is always bilateral and caused by increased intracranial pressure. Papillitis is usually unilateral.
What are the two main types of Ischemic Optic Neuropathy?
1. Ateritic: Giant Cell (Temporal) Arteritis
What are the two main symptoms indicative of Giant Cell Arteritis?
1. Scalp Tenderness
2. Jaw claudication
What two objective tests can be used to confirm Giant Cell Arteritis?
1. Westergren Sedimentation Rate
2. CRP (c-reactive protein)
What is the treatment for Giant Cell Arteritis if the sed. rate is over 60?
High dose corticosteroids with H2 blockers to protect the stomach.
What usually causes a unilateral homonymous hemanopia?
Optic tract lesion
What normally causes tunnel vision (bilateral temporal hemanopia)?