Eye Stuff (B&B Exam 2) Flashcards
What is Astigmatism?
What is affected in Astigmatism?
Astigmatism is an eye disorder in which the CORNEA is irregularly shaped. This is a common cause of refractive error, or poor light focusing capacity of the eye.
What are 2 lens disorders?
Cataracts and Presbyopia.
What is Presbyopia?
What part of the eye does it affect?
Presbyopia is a loss of accommodation. This is a major change in the lens itself. The elasticity of the lens decreases with age and leads to a hardening of the lens.
What is a Cataract?
What part of the eye does it affect?
With decreasing age, the LENS becomes yellow and cloudy and results in decreased vision. This results in blurry vision, glare, decreased contract sensitivity and decreased color.
What is the treatment for cataracts?
There is no way to prevent/treat cataracts with medicine.
These are common in Diabetics.
Surgery is indicated if there is significant visual impairment for daily activities (driving, reading TV, cooking, sewing).
What is Glaucoma?
What part of the eye does it affect?
Glaucoma affects the optic nerve!
It is associated with visual field defects and may be associated with high Intraocular Pressure (IOP). It is the 2nd most common cause of visual loss in the elderly.
What groups are at risk for Glaucoma?
Elderly, African Americans, Individuals with high IOP, Diabetes, High myopia, 1st degree relatives with glaucoma
How do you determine if someone has Glaucoma?
- Check the eye pressure: acclimation tonometry
- Visual field test: automatic machine
- Check the optic nerve cupping ratio (0.4 or less is normal)
What are the 2 types of Glaucoma?
Which one is a medical emergency?
Open angle glaucoma and closed angle glaucoma.
Closed angle glaucoma is a medical emergency!
In which population is Open Angle Glaucoma most common?
The elderly.
This is treated with medications (drops or pills).
What is the purpose of Primary Open Angle Glaucoma treatment?
- To halt further visual loss
- To halt further optic nerve damage
- To decrease intraocular pressure (IOP)
Who is at risk for Closed Angle Glaucoma?
Asians, females, hyperopia (far sighted) people
What is the treatment for Closed Angle Glaucoma?
An iridotomy - you create a hole in the iris to allow the aqueous humor fluid to drain through.
What are the symptoms of Closed Angle Glaucoma?
Severe ocular pain, redness, the pupil is mid-dilated, headache, nausea, vomiting, the eye itself is rock hard!
What is Age-Related Macular Degeneration (ARMD)?
It is the #1 leading cause of visual loss in the elderly. It leads to CENTRAL vision loss.
What are the risk factors for ARMD?
Advanced age (>70), Fair skin, family history of ARMD, smoking and heart disease.
What are the 2 types of ARMD?
Dry and Wet ARMD
What happens in Dry ARMD?
There are many Drusen deposits (extracellular deposits) that accumulate under the Retina!
Symptoms: Usually asymptomatic, difficulty reading and driving, straight lines look crooked
What happens in Wet ARMD?
- Sudden, severe visual loss
- Bleeding under the retina: leads to central vision loss
How can you prevent Wet ARMD if you have Dry ARMD?
Eat a diet high in fruit and vegetables (antioxidants)
Dietary supplements: Vitamins C, E, beta carotene, zinc oxide, cupric oxide
What is the treatment for Wet ARMD?
- Laser photocoagulation
- Photodynamic therapy with verteporfin
- Intraocular injection therapy with anti-vascular endothelial growth factor (VEGF) drugs
What is Diabetic Retinopathy?
It is the 4th leading cause of visual loss in the elderly.
It is the leading cause of blindness in working age Americans (20-74).
How does Diabetic Retinopathy occur?
Increased blood GLUCOSE levels damages retinal capillaries, leads to the loss of capillary pericytes (which maintain the integrity of the endothelial cells) and leads to breakdown of the blood-retinal barrier.
Increased glucose –> VEGF –> capillary permeability/vasoproliferation
What are the symptoms of Diabetic Retinopathy?
Microaneurysms, venous bleeding, hard exudates, intraretinal hemorrhages, cotton wool spots (retinal ischemia)
What is Diabetic Macular Edema?
Clinically significant Macular Edema (CSME)
This is the most frequent cause of visual loss in Diabetics because of the fluid associated with it.
What happens in Proliferative Diabetic Retinopathy?
Neovascularization: growth of blood vessels; bleed easily
Vitreous Hemorrhage and Traction: “floaters”, severe visual loss
What is traction?
Where does it occur?
Traction: When a fibrovascular scar tissue forms; it can lead to retinal detachment
Proliferative Diabetic Retinopathy
What is the treatment for Diabetic Retinopathy?
Standard of care: Laser photocoagulation surgery
Also: intraocular Anti-VEGF agents, intraocular steroid injections, vitrectomy
What is Retinitis Pigmentosa?
A disorder of the RODS.
Symptoms: Progressive retinal degeneration, pigmentary deposits, optic nerve atrophy, night/low vision blindness, tunnel vision
What is Optic Neuritis?
An inflammatory optic neuropathy!
The pathogenesis is presumed demyelination.
What is Optic Neuritis associated with?
MS, Sarcoidosis, certain infections
Who does Optic Neuritis effect?
People less than 40 years of age
What is the clinical course of Optic Neuritis?
On examination, the optic nerve may appear swollen OR normal.
The visual loss typically reaches nadir in several days to 2 weeks after onset –> recovery over the next few weeks to months –> some visual loss may persist
What is the treatment for Optic Neuritis?
High dose IV steroids (accelerated visual recovery) within the first few weeks
What is Papilledema?
The swelling of the optic disc caused by increased ICP
What causes Papilledema?
Intracranial mass, hydrocephalus, pseudotumor cerebri, malignant hypertension
What is the prognosis for Papilledema?
As many as 40% of nerve axons may be loss before there is any detectable visual field defect. Once visual loss begins, it is usually rapidly progressive.
What does the sphincter muscle do?
The sphincter muscle’s contraction leads to miosis (pupillary constriction).
What is the Sphincter Muscle innervated by?
It is innervated by the parasympathetic system.
What does the Dilator muscle do?
The contraction of the dilator muscle leads to mydriasis (pupillary dilation).
What is the Dilator Muscle innervated by?
Sympathetics
How does the Consensual Light Reflex work?
It is based on the decussation at the chiasm and bilateral input to the Edinger-Westphal nuclei from the pre-tectal nuclei.
What is a Holmes-Adie Tonic Pupil?
This is an idiopathic condition in which 1 of the pupils is abnormally large. The abnormally large pupil constricts poorly to light and better to accommodation.
What are Argyll Robertson pupils?
These are pupils that are bilaterally miotic (small). There is an absence of the pupillary light response but accommodation (constriction to near objects) is intact.
What are some potential causes of Argyll-Robertson pupils?
Neurosyphilis, Diabetes, Sarcoidosis, Alcoholism, MS
How does a pupil involved in a CN III palsy present?
The affected pupil is mydriatic (large), looks “down and out” and does not accommodate to light or near objects.
What are some possible causes of a CN III palsy?
Aneursym of the Posterior Communicating Artery (PCom) or an Uncal Herniation!
What is a Hutchinson Pupil?
A Hutchinson pupil can be seen on a comatose patient. They present with a unilateral, dilated, poorly reacting pupil. This is due to an intracranial mass or mass effect.
How does Horner Syndrome present?
Horner syndrome presents with miosis of the affected pupil, anhidrosis of the affected side of the face and ptosis.
What are some potential causes of Horner Syndrome?
CAROTID problems, disease in the neck or chest
