Ocular Disease 3.1-3.4 Flashcards
(278 cards)
What is sclerotic scatter and what is it used for?
a. Too look for corneal clarity
b. Illumination and ocular about 60 degrees apart. Focus light on temporal limbus (should create halo around iris) – creating total internal reflection. Look outside of oculars
What is a optic section used for?
a. Depth
b. Van herick angles
What is a conical beam used for?
a. Look for cells and flare (should be dark adapted)
What is specular reflection and what is it used for?
a. Idea of equal angles – incident and reflective angle. Focus light on purkinje image – endothelium and epithelium light up
b. Can also be used to look at posterior and anterior lens surface
What is indirect illumination used for?
a. Non- opaque corneal lesions – like those seen in EBMD
What are the lesions in EBMD called?
a. Map dot
b. Fingerprint
- What are you looking at when using the cobalt blue filter + NaFl?
a. Tear film and corneal integrity
b. NaFl stains defects
- What can you see with the cobalt blue filter, but no NaFl
a. Fleisher ring - will appear black
Decemets membrane
- What is the Fleisher ring?
a. Circular Iron deposit at base of cornea seen in keratoconus. In descemets
- Alkali vs acidic burn
a. Alkali – blanches = ichemia, more penetrate deeper and faster because of disruption of the fatty acids in the cell membrane due to increase in pH.
- What is the most common alkali agent causing burns?
a. CAOH
- Why does an abrasion cause a mitotic pupil?
a. An irritated cornea sends a signal to the iris via CN 5 = reflex
- How do you treat an abrasion and why?
a. Doxy – to inhibit MMP’s = enemies
- What causes a recurrent Corneal Erosion?
a. Abrasion
b. All corneal dystrophies
- You see a foreign body with a sterile infiltrate, what is the cause?
a. Vegetative or plant matter
b. NOTE: a sterile infiltrate is not always seen in plant or vegetative foreign bodies
- What does it mean if you see linear vertical corneal scratches?
a. Superior lid foreign body
- What causes a hyphema? What testing should you do?
a. Sickle cell – especially if have recurrent hyphema
b. Trauma
c. Clotting disorder – recurrent hyphemas
d. NSAIDs/ blood thinners
e. Idiopathic
i. Do sickle cell testing, CBC, PT/PTT
- What must you avoid if you have a hyphema or orbital fracture?
a. Gonio and scleral depression for 1 month minimum because it can cause rebleeds
- What is a positive seidel sign?
a. Leaky NaFL – indicates Aqueous leaking out of eye
b. Indicated an open globe wound – good to do it when see any corneal/ conj trauma
- When do you need a B scan?
a. To view post pole if unable to do BIO/78/90 – for RD
b. To differentiate between a melanoma ( optically empty) and a choroidal nevus
c. Optic nerve head drusen – lights up
- What are the different types of hyphema?
a. 8 ball hyphema – entire anterior chamber is filled with blood
b. Microhyphema – only see RBCs suspended with a slit lamp in the anterior chamber
- What is iridodialysis ?
a. The iris root is torn from the CB.
- What do you need to monitor for with a patient who has iridodialysis?
a. Angle recession glaucoma
- What is the thinnest and thickest part of the iris?
a. The iris root is the thinnest part of the iris
b. Collarette = thickest