Lecture 1: Intro to Ophthalmology Flashcards
What are the 3 layers of the eye?
Fibrous: Sclera and Cornea
Vascular: Iris, pupil, ciliary body, choroid
Neural: Retina, photoreceptors, optic nerve
What kind of humor fills the anterior and posterior sections of the eye?
Anterior: Aqueous humor
Posterior: Vitreous humor
What are the macula and fovea?
Macula: pigmented center of the retina.
Fovea: Center of the macula itself. Highest area of visual acuity.
When I look at something close by, what happens to my lens?
It gets thicker.
What are the focal point and refraction?
Focal point: where light focuses on the retina. Good vision requires a focal point precisely on the retina.
Refraction: Bending light to produce a focused image on the retina.
What is myopia and how is it corrected?
Myopia is nearsightedness, so you require a concave lens to diverge the light. It will make objects smaller than they appear.
What is the mnemonic for myopia vs hyperopia?
Need Medical Doctors for Healthy Children.
Near Myopia diverging
Far Hyperopia converging
What is hyperopia and how is it corrected?
Farsightedness, aka nearby objects look blurry.
The lens is focusing light past the retina.
Corrected via a convex lens to magnify objects.
What kind of lens is a magnifying glass?
Convex. Focuses light to a closer point.
What is the mnemonic to remember a concave lens’ refraction?
Cave diver.
Concave divergent.
What is astigmatism?
Light reflecting to multiple focal points.
It is caused by irregular cornea/lens shape.
What is presbyopia?
Age related farsightedness.
Loss of mobility and focusing power of lens.
Requires reading glasses to correct.
What is keratoconus?
Thinning of cornea, resulting in blurred vision, photosensitivity, and glare. Unknown etiology, but often pts have hx of corneal transplants or vision correction.
What are the two photoreceptors of the retina? Which one does what?
Cones = color (RGB)
Rods = black and white
What two parts of the eye lack blood vessels?
Cornea and Lens
They get their nutrients from aqueous humor.
What is the main purpose of aqueous humor? What makes it?
Maintaining intraocular pressure.
Made by the ciliary body.
What is the main purpose of vitreous humor?
Maintaining eyeball shape and holding lens in place.
More jelly-like.
What is glaucoma characterized by exam wise?
Cupping of the optic desk on ophthalmic exam.
What is the leading cause of blindness? Second?
Leading: CATARACTS
second: glaucoma
What part of the nervous system controls pupillary dilation and constriction?
Dilation = Sympathetic
Constriction = Parasympathetic
What is anisocoria?
One pupil larger than the other.
What is a marcus gunn pupil/relative afferent pupillary defect? (RAPD)
Normal consensual response.
NO DIRECT response.
What is Horner’s triad?
PAM Horner
Ptosis
Anhidrosis
Miosis (excessive pupillary constriction)
Miosis is most apparent in dim light.
What physical feature would make us suspect Horner’s syndrome?
Associated heterochromia (diff eye colors)
What is adie’s pupil/tonic pupil?
Slow or lack of pupillary reaction to light.
Often associated with diminished DTRs. (Holmes-Adie syndrome)
Common in women 30-40.
What is argyll-robertson pupil?
Pupils restricting only to accommodation but not light.
Hallmark of tertiary syphilis!!!!
Usually bilateral.
ARP
(Accomodation reflex present.
Pupillary reflex absent!)
What is the most common exam finding for cataracts?
No red reflex.
What non-eye chronic conditions can prompt a fundoscopic exam?
HTN
Diabetes
What are cotton wool spots and what causes them?
Soft exduates, like clouds on the retina.
MC: Diabetic retinopathy and HTN retinopathy.
What is retinal detachment often described as and what is the MC?
Like a curtain coming down on the eye.
MC: Diabetic neuropathy.
How does papilledema present?
- Ill-defined margins
- Disc elevation
- Venous distension and tortuosity
- Obscured disk
- Lack of venous pulsations
How does retinal vein occlusion often present?
Widespread hemorrhaging, creating a blood and thunder fundus.
What exam finding is highly suggestive of a central retinal artery occlusion?
Red cherry spot on the fovea.
Also boxcar segmentation
What is A-V nicking? MC?
Artery crossing vein.
Compresses small vein.
MC: HTN retinopathy.
What condition is the MC for copper and silver wiring?
HTN retinopathy
What is copper and silver wiring?
Atherosclerotic vessel wall thickening and chronic HTN.
Copper is the early stages.
Silver is late stages.
What are hard exudates? MC?
Small, white/yellow blotches with distinct borders.
Diabetic retinopathy.
What are flame hemorrhages? MC?
Necrotic vessels bleeding into the nerve fiber layer.
Diabetic/HTN retinopathy
What are dot-blot aneurysms?
Microaneurysms erupting in deep retina.
What is neovascularization? MC?
Ischemia/damage causing VEGF release. Many new vessels forming.
Diabetic retinopathy and macular degeneration
What is retinal drusen? MC?
Yellow deposits under the retina, mainly in the macular region.
Age-related macular degeneration (AMD)
What differentiates hard exudates from retinal drusen?
Retinal drusen is macula centered.
Hard exudates are typically spread out everywhere.
What is a slit lamp usually used to examine?
Anterior chamber of the eye.
What is a fluorescein stain usually used to check for?
Corneal abrasions, ulcers, and foreign bodies.
What are the steps to check for a corneal abrasion?
- Instill tetracaine to numb eye
- Apply fluoroscein stain to eye 60s later, ask pt to blink a few times.
- Use a wood’s lamp or cobalt blue filter.
- Uptake indicates corneal abrasion
