Ophthalmology Flashcards
(235 cards)
What should you ask on history for acute vision loss?
- HPI - onset, duration, progression, and location (whether it is monocular or binocular and whether it involves the entire visual field or a specific part and which part)
- The patient should be asked about eye pain and whether it is constant or occurs only with eye movement.
- ROS: Jaw or tongue claudication, temporal headache, proximal muscle pain, and stiffness (giant cell arteritis); and headaches (ocular migraine).
- PMx: Risk factors for eye disorders (eg, contact lens use, severe myopia, recent eye surgery or injury), risk factors for vascular disease (eg, diabetes, hypertension)
What should be performed on the eye examination for acute vision loss?
- Visual acuity
- Peripheral visual fields (confrontation)
- Central visual fields are assessed by Amsler grid.
- Direct and consensual pupillary light reflexes are examined using the swinging flashlight test.
- Ocular motility is assessed.
- Color vision is tested with color plates.
- The eyelids, sclera, and conjunctiva are examined using a slit lamp if possible.
- The cornea is examined with fluorescein staining.
- The anterior chamber is examined for cells and flare in patients who have eye pain or conjunctival injection.
- The lens is checked for cataracts using a direct ophthalmoscope, slit lamp, or both.
- Intraocular pressure is measured.
- Ophthalmoscopy after dilating the pupil with a drop of a sympathomimetic; dilation is nearly full after about 20 minutes. The entire fundus, including the retina, macula, fovea, vessels, and optic disk and its margins, is examined.
What is the Ddx for acute vision loss?
Cornea/Anterior Segment:
- Corneal edema
- Hyphema (blood in anterior chamber)
- Acute angle-closure glaucoma
- Trauma/foreign
Vitreous/Retina/Optic Nerve
- Vitreous hemorrhage (caused by diabetic retinopathy or trauma)
- RD
- Retinal artery/vein occlusion
- Acute macular lesion
- Optic neuritis
- Temporal arteritis
- Anterior ischemic optic neuropathy (AION)
Cortical/Other
- Occipital infarction/ hemorrhage
- Cortical blindness
- Functional (non-organic, diagnosis of exclusion)
Cornea is relatively dry and clear normally and that clarity is maintained by passive resistance of water by _____ and ____
Epithelium
Endothelial pump function
How does corneal edema occur?
Edema thus results when the pump is not working (trauma, uveitis, infection) or if too much fluid is getting into stroma (epithelial defect or high IOP – acute rise – angle closure glaucoma).
Causes of corneal edema?
Causes: angle closure glaucoma, post-op, abrasion, Fuchs’ Dystrophy
What causes corneal opacity?
Can be caused by a keratitis (HSV, marginal - hypersensitivity reaction to the death of bacteria or infectious – caused by contact lens use) or corneal scar from HSV treatment
What is the key to diagnosis of corneal opacity?
Key to diagnosis – decreased vision, white corneal infiltrate, epithelial defect, with anterior chamber inflamm.
Risk factors of corneal opacity?
Risk factors: diabetes, trauma, alcoholics, debilitated/elderly, CL.
Treatment of corneal opacity?
Treatment: culture scrapings, admit if >2mm, abx.
What is hyphema?
Blood in anterior chamber from blunt trauma or neovascularization
What is vitreous hemorrhage?
Blood in vitreous space
Risk factors for vitreous hemorrhage?
Risk factors (eg, diabetes, retinal tear, sickle cell anemia, trauma)
Clinical features of retinal detachment (RD)?
Recent increase in floaters, photopsias (flashing lights), or both
Visual field defect – loss of peripheral vision, retinal folds
What is retinal detachment (RD)?
OCULAR EMERGENCY caused by fluid accumulation UNDER retina.
Etiology of retinal detachment (RD)?
Exudative (leaks under it)
Rhegmatogenous (enters through a hole, MUCH MORE COMMON).
• These holes happen because of intrinsic weakness causing thinning of retina or traction (vitrous pulls on weak spots and rips retina, usually peripherally cause the retina is attached at optic nerve and peripheral retina).
• Thus most tears occur due to a change in vitreous dynamics. Usually from a posterior vitreous detachment (PVD).
Treatment of retinal detachment (RD)?
Treatment: Should be referred ASAP if macula on and 1-2d if macula off
Risk factors of retinal detachment (RD)?
Risk factors (eg, trauma, eye surgery, severe myopia; in men, advanced age)
Key to diagnosis of posterior vitreous detachment?
Keys to diagnosis: new floater, Decreased vision if tear of retina, photopsia – because of mechanical stimulation of photoreceptors)
Pathogenesis of posterior vitreous detachment?
The 360-deg attached vitreous becomes liquefied (syneretic) with age causing intra-vitreous tractional forces that pull at its attachment. Eventually this traction overcomes optic nerve attachment having a plunger effect leading to a PVD. Because the vitreous is more free once the PVD is released, the traction is now exerted more strongly at the ora (on the retina)
PVD vs RD
- A PVD presents with a new floater, flashing lights, and maybe decreased vision. Only 10% have a tear.
- A RD presents with decreased vision, photopsia, a recent floater, and a field defect
How soon should you treat PVD?
For PVD, treat within 1-2d so it does not become an RD!
Leading cause of permanent vision loss in elderly
Age-Related Macular Degeneration
What are the 2 types of Age-Related Macular Degeneration?
- Non-Exudative/”Dry” (Non-Neovascular) AMD
- Exudative/”Wet” (Neovascular) AMD