Lec.6: POAG Flashcards
what are common signs and symptoms of POAG?
chronic, bilateral, often asymmetric, acquired optic nerve fiber loss, acquired VF loss, open chamber angle, IOP often over 21 mmHg
what process does glaucoma accelerate?
apoptosis of retinal ganglion cells
name common glaucoma risk factors.
IOP, age, race, genetics, thin cornea, vascular disease, myopia
is it easier to lower IOP from 15 mmHg to 12 mmHg or is it easier to lower IOP from 30 mmHg to 18 mmHg?
easier to drop from 30 mmHg to 18 mmHg, because 15 mmHg is already in the normal range for IOP
what percentage of patients with elevated IOP have VF loss?
1/10th of patients (Sommer 1991)
what percentage of patients with disc and VF damage have an IOP less than 21 mmHg?
1/6th
what percentage of patient with OHT develop glaucoma in 10 years?
15%-40%
how much more prevalent is blindness in african americans than in caucasians?
8x
IOP is a poor screening tool due to a low sensitivity, what is the sensitivity of IOP measurements?
47.1%
by how much does OCT tend to underestimate corneal thickness, when compared to ultrasound techniques?
15-20 microns
what procedures should be performed twice a year on glaucoma patients?
VF, OCT, Fundus
how many times should IOP be measured in a year for glaucoma patients?
4 times a year
what is the conventional IOP target pressure for patients with glaucoma?
20-30% decrease in IOP
what should be target IOP for a patient with SEVERE glaucoma?
40% decrease in IOP
what is the equation for target pressure?
Target Pressure= (Max IOP)- (Max IOP%)- (Z score)
how many times a year should you perform gonio on a glaucoma patient?
1 time a year
how many times should you perform pachymetry for a glaucoma patient?
once in a lifetime
in POAG what is the incidence of blindness (unilateral vs. bilateral) 20 years after initial diagnosis?
27% vs. 9%
what are the chances of glaucoma progression in patients being treated for glaucoma vs. a control group?
12% treated group 35% control group
what are the chances of developing catarct in patients being treated for glaucoma vs. a control group?
38% treated group 14% control group
what does argon laser trabecularplasty (ALT) do?
causes shrinking of TM
can SWAP and FDT aid in early diagnosis of POAG?
no, but it was once believed they did
what is the definition of regression to the mean?
on average, individuals tend to have some variance in physiological norms but they often vary around a mean (think weight loss and weight gain)
what are the chances of progression in OHT in treated vs untreated groups?
4.4% treated group 9.5% untreated group
in OHT what are the baseline factors that predict onset and progression of POAG?
older age, larger vertical or horizontal CD ratio, greater PSD, higher IOP
in OHT what is the strongest association of progression of POAG?
lower corneal thickness
what is the primary glaucoma indicator?
optic disc changes
what percentage of glaucoma patients would be detected by optic disc changes?
2/3rds
what percentage of glaucoma patients would be detected by VF changes?
1/3 or (35%)
describe the average corneal thickness of a patient with OHT?
they tend to have thicker corneas
what would be the chances of glaucoma damage in patients with a 40 micron decrease in corneal thickness?
70%
(T/F) in the long run drugs are cheaper than laser treatment?
false
according to Moorfields primary treatment trials, what procedure is greater at lowering IOP than trabeculoplasty and medicine combined?
trabeculectomy
what is the goal IOP for patients with advanced glaucoma?
12 mmHg and lower
which ethnicity has lesser VF loss with trabeculectomy?
caucasians (african americans tend to scar more and patch the passage created when compared to caucasians)
which ethnicity had less progression of glaucoma with laser trabeculoplasty?
African Americans
what does a trabeculectomy do?
creates a cut to allow for aqueous humor exchange
is it true that 20% IOP reduction in OHT patients may not prevent progression?
yes
describe the following:
notching at 6 oclock
describe the following:
endstage glaucoma
