Glaucoma Theories and ONH Risk Factors (M) Flashcards
What is the correction factor while calculating the diameter of a cup while performing fundoscopy with a 78D lens?
1.1
What is the pigmentation that is directly adjacent to the ONH that occurs when the retina and choroid are pulled away?
scleral crescent
What are the glaucomatous optic nerve appearances?
- inc cup size/thinning of rim over time
- C/D ratio asymmetry
- vertical elongation
- inc cup depth (laminar dot sign)
- focal thinning of rim tissue (notching)
- bayoneting of vascular tree
- disc heme
- saucerization
- beta zone peripapillary atrophy
What is the pigmentation that is directly adjacent to the ONH that occurs when the entire retina is present but it is atrophied?
PPA (peripapillary atrophy)
What is the appearance of vessels that come out of the cup that disappear because they are going under the rim tissue?
bayoneting of vessels
What other optic neuropathies must be ruled out that a re differential diagnoses of glaucoma?
- AION
- optic neuritis
- compressive optic neuropathy
What is the pigmentation that is directly adjacent to the ONH that is the examiner looking directly at the choroid (retina pulled away)?
choroidal crescent
Do larger discs have relatively larger or smaller cups?
larger
Where into the ONH do the most peripheral portions of the retina come enter/align?
peripheral
What defines ocular hypertension?
pressure 2 standard deviations above the norm
What is the correction factor while calculating the diameter of a cup while performing fundoscopy with a 90D lens?
1.3
What are the diagnostic pearls of glaucomatous damage versus neurological damage?
- area of ONH subject to cupping greater than are subject to pallor for glaucoma (blood vessels bending)
- inc in cupping precedes inc in pallor for glaucoma
- VF loss from non-glaucomatous much worse than expected from the appearance of the nerve
What is based on the radial width of the neuroretinal rim measured at its thinnest point and is an assessment tool?
Disk damage likelihood scale (DDLS)
What are the 5 R’s of ONH analysis?
- scleral ring
- neuroretinal ring
- retinal nerve fiber layer
- region of PPA
- retinal hemes
What is the best way to detect change in PPA over time?
fundus photos
What is a group of ocular diseases with various causes that ultimately are associated with a progressive optic neuropathy leading to loss of visual function?
galucoma
What is the most important ocular risk factor for a possible glaucoma patient?
optic nerve head assessment
Where are the larger holes in the ONH lamina cribosa?
superior and inferior
What percentage of glaucoma remains undiagnosed?
50%
What is the most important aspect of the ONH assessment?
neuroretinal rim thickness
What is a splinter shaped heme on the rim of the optic nerve that is assumed to be due to glaucoma? 1. What else can cause these? 2
- drance hemorrhage
2. CRAO, acute PVD, HTN retinopathy
What is the theory of glaucomatous damage that states that once damage to ONH occurs, there is a release of biochemical substances that can continue the progression of damage to neighboring cells even with a low IOP?
biochemical theory of glaucomatous damage
What is the best interpretation of the ISNT rule?
superior and inferior rims should never be the thinnest
What is the vertical optic nerve disc diameter that is considered to be small? 1. Average? 2. Large? 3
- less than 1.5mm
- around 1.8mm
- greater than 2.2mm
What is an appearance of the ONH that is extremely hard to judge the C/D because it is so large and shallow (hiding pallor)?
saucerization
About what percentage of your NFL must you lose for a visual field defect to show up?
30 to 40%
How long is the patient usually treated for glaucoma once they are diagnosed?
lifetime
