OPHTHALMOLOGY: 476-479 Flashcards
What type of vision impairments improve with glasses?
Refractive errors
What are 4 types of refractive errors?
- Hyperopia
- Myopia
- Astigmatism
- Presbyopia
What is hyperopia?
Eye too short for refractive power of cornea and lens - light ends up being focused behind the retina
What is myopia?
Eye too long for refractive power of cornea and lens - light ends up being focused in front of the retina
In a patient with astigmatism, why is the refractive power different at different axes?
Abnormal curvature of the cornea
Why is there a decrease in focusing ability during accommodation in presbyopia?
Sclerosis and decreased elasticity
Name the 2 structures inflamed in uveitis and 2 accompanying symptoms.
2 structures: anterior uvea and iris
2 symptoms: hypopyon (sterile pus) and conjunctival redness
What does long term retinitis lead to?
Scarring (from retinal edema and necrosis)
Name 3 common causes of retinitis.
Viral - CMV, HSV, HZV
What type of patient is more likely to get retinitis?
Immunosuppressed
On physical exam, you notice that a patient has a cloudy retina with attenuated vessels and a “cherry-red” spot at the fovea. What is your diagnosis?
Central retinal artery occlusion
How does central retinal artery occlusion present?
Acute, painless monocular vision loss
What is retinal vein occlusion usually secondary to?
Blockage of the central or branch retinal vein is often secondary to compression from nearby arterial atherosclerosis
What 2 things are typically observed in retinal vein occlusion in the affected area?
Retinal hemorrhage and edema
What are the 2 types of diabetic retinopathy?
Proliferative and non-proliferative
What metabolic imbalance causes diabetic retinopathy?
Chronic hyperglycemia
Describe what happens in non-proliferative diabetic retinopathy.
Damaged capillaries leak blood –> lipids and fluid seep into retina –> hemorrhages and macular edema
What is the treatment for non-proliferative diabetic retinopathy?
Blood sugar control, macular laser
What proliferates in proliferative diabetic retinopathy and why?
New blood vessel formation due to chronic hypoxia. This leads to traction on the retina.
What is the treatment for proliferative diabetic retinopathy?
Peripheral retinal photocoagulation, anti-VEGF injections
Describe the flow of aqueous humor.
- Synthesized by the ciliary epithelium on the ciliary muscle
- Secreted into the posterior chamber
- Flows between the front of the lens and the back of the iris into the anterior chamber
- Drains out of the eye via trabecular meshwork into the Canal of Schlemm