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- What is the process that measures the anterior projection of the corneal relative to the lateral orbital rim?
- Exophthalmometry
- What are a ton of causes of exophthalmos?
-
1- graves disease (unilateral)
2- orbital tumor
3- idiopathic intracranial HTN
4- brain abscess
5- cavernous sinus thrombosis - What are 3 causes of enophthalmos?
-
1- blown out fracture
2- age-related orbital fat
3- congenital (bilateral) - What might you see with exopthalmus? What is this a sign of?
-
pulsatile proptosis
a sign of arteriovenus aneurysm of the orbit - What 2 things might trick you into thinking EXO?
- lid retraction and ptosis
- What are 2 pieces of equip. that can measure EXO/ENDO?
-
1- Hertel (gold standard)
2- Leudde (what we bought) - What measurment must you keep the same everytime you use the HERTEL?
- The Base measurement
- How many times should ou perform the Leudde?
- 3 times, record the average
- To what standard are the eye measurements for exopthalmometry compared?
- each eye to each other, and against the norms
- What are the avgerages for EXO?
-
Caucasians: 12-20
AA: 12-24
Kids: a little smaller - What is the inner eye comparison?
- 2-3mm b/t the eyes
- A change in more than ___ is signifcant. (in exopthalmometry)
- 2mm
- What are 4 tests that test the Potential VA?
-
1- standard pinhole (Best correct < 20/40)
2- Super pinhole
3- PAM (potential acuity meter)
4- Laser Interferometer - T or F: The potential VA tests reveal the visual capabilities of the retina.
- True
- If VA get better with standard pinhole, you can conclude that loss of VA is _______ in nature.
- Refractive
- What can super pinhole be used to detect?
- the post-op VA following cataract surgery
- If a patient has a poor response with standard PH and a better response with super PH--what can you deduce?
- maybe the patient has mild/moderate maculopathy
- How does the Super PH act optically?
- It contracts the image cone and enhances the depth of focus
- What is special about the eye chart in super PH?
- It is transilluminated 1000 times brighter than the snellen chart
- How big is the pin hole in super PH?
- 1.5mm
- Is the patient fully dilated during super PH?
- YES (bummer)
- Does the patient wear correction during PH?
- NO!!!!!!!
- What is a VERY specific feature of the super PH test?
- You must hold the chart 5 feet from the patient.
- How do you record for super PH?
- SPH: 5/10 OD, 5/20 OS
- What special test uses an intense light to project a tiny snellen eye chart directly into the eye?
- PAM
- What are 2 "catches" when doing the PAM test?
-
1-You must compensate for refractive error or the patient!
2- you must shine the chart through a window in the opacity - Is the patient dilated during PAM?
- Yes!!
- T or F: the instrument for PAM is attached to the slit lamp.
- True
- Post-op acuity is usually ____ or ____ than PAM acuity.
- good or better
- What are some problems that might give you a low potential VA, when you really should have a higher VA?
-
1- poor dilation
2- dense cataract
3- poor fixation
4- illiteracy
5- poor comprehension - What is the potential acuity test that uses 2 coherent beams to create a 3-d image on the retina?
- Laser Interferometry (LI)
- Is LI independent of the eye optics?
- yes
- What does LI actually test?
- the macular and cortical function of the visual system.
- Is the patient fully dilated for LI?
- yes (just as in SPH and PAM)
- What is the end result of LI?
- The finest grating that the patient can observe 50% of the time.
- What can you perform to test Glare?
- BAT Brightness Acuity Test
- Define Glare/
- A visual perception created when external light becomes scattered within the eye---produces haze over retina
- Does glare make vision even worse if you already have a cataract too?
- yep
- What is the exact definition of the BAT?
- an objective measurement of disability secondary to opacity
- What test would you do if the patient have 20/20 vision but complains of terrible vision at night?
- BAT
- What are some patients affected by glare?
-
1- cataract (PSC)
2-post cortical spoking
3- aphakic and pseudophakic
4- PCO (post capsular opacification)--Elschnigs pearls - What are Elschnigs pearls?
- capsular fibrosis
- Is the patient fully dilated for BAT?
- NO NO NO!!!!
- When you do begin testing best VA during the BAT?
- after the patient has dark adapted for 20/30 seconds
- Do you wear correction during BAT?
- yes......you gotta see that eye chart 20 feet away
- What are 3 tests for macular Integrity?
-
1- Amsler Grid
2- MAcular photostress recovery
3- Watzke-Allen - What are 2 clinical findings that might suggest early Macular disease?
-
1- mildly decreased VA
2- opthalmic findings - What is the purpose of the Amsler grid?
- to detect and monitor defects in the central visual field
- Who are 5 patients that might need the amsler grid?
-
1- unexplained decrease in vision
2- macular disruption
3- any visual disturbances
4- diabetic patient
5- taking Plaquenil or Chloroquine - On the Amsler grid each square is _____ when held at _____.
- 1 degree at 30 cm
- What is the field size for the amsler grid?
- 10 degrees on either side of fixation (20 degress total)
- Is the patient fully dilated for the amsler grid? Do they wear correction?
- no, yes--wear NEAR correction
- If the patient reports wavy lines--what is this called?
- metamorphopsia
- If a part of the grid is missing--this is a _____.
- scotoma
- If part of the grid is simply blurry or hazy--this is a _________.
- relative scotoma
- What are some common reasons to see wavy lines on the amsler grid?
-
1- coalesced drusen
2- ERM
3- macular edema
4- CNVM
5- macular detachment - If that patient reports a monocular central scotoma with no opthalmic findings, look for ______?
- mass lesion in anterior visual pathway (before chiasm)
- Quandrantic hemianopic defects are located _____.
- post- chiasm