Influential Studies Flashcards
Conversion of OHTN to POAG over 5 years for IOP 21-25
3%
Conversion of OHTN to POAG over 5 years for IOP 26 to 30
12-26%
Conversion of OHTN to POAG over 5 years for IOP >30
42%
What is the purpose of collaborative NTG study?
if you have GLC ONH changes but normal IOP, can lowering the IOP reduce progression
What were the arms of the CNTGS?
no tx or aggressive tx to reduce IOP 30% using pilo or CAIs
What were the CNTGS results?
30% IOP reduction achieved with gtts and ALT ~50% leading to VF progression decrease from 35% to 12% HOWEVER some untreated disease did not progress
What risk factors were identified with the CNTGS?
migraines, female, disk hemes (indicator of profression)
What were non factors in the CNTGS?
age, entering IOP, HTN, DM, Strok
What is the conclusion of the CNTGS?
decreasing IOP reduces GLC progression even if NTG but 20% of untreated did not progress
What is the purpose of the OHTS?
will decreasing IOP reduce risk of progression to POAG in ocular hypertensives
What were the OHTS treatment arms?
monitor and tx to IOP of 24 and at least 20% IOP reduction with topical meds
What were the OHTS results?
average IOP reduction 22% in treated group, probability of progressing to POAG decreased from 10% to 5% with treatment, most converted on ONH appearance not VF
What are risk factors for conversion from the OHTS?
larger C/D, increased age, higher pattern SD, thinner central cornea, AA
What fraction of AAs converted from OHTN to POAG?
1/3 converted in OHTS 2
What central corneal thickness has a greater risk of GLC?
<555 microns had 3x conversion risk vs 588
T/F it is harder to push inwards on a thicker cornea
true, results in higher measured IOP
What does collagen structure have to do with this?
collagen structure that makes a cornea thicker could relate to collagen structure at lamina cribrosa; however the ebryological tissues are different
What is true of AA corneas?
they are thinner by about 25 microns
What two characteristics give the highest risk of glaucoma?
high IOP and thin cornea
What was the average central corneal thickness from the OHTS?
545 microns
What is the purpose of the AGIS?
evaluate ALT vs trabeculectomy/otomy
What were the treatment arms of AGIS?
ALT, trabeculectomy, trabeculectomy vs trabeculectomy, ALT, trabeculectomy
What was the goal IOP for AGIS treatment?
IOP less than 18 mmHg
What is the ALT?
argon laser trabeculoplasty, thermal laser to meshwork
What is the trab?
trabeculectomy, port in AC drains to subconj bleb
What were the AGIS results?
race mattered with treatment efficacy, 78% increase risk of cataracts with trab, notched ONH had less progression
According to AGIS how should treatment go for AAs?
ALT first (trab greater failure rate in AA)
According to AGIS how should treatment go for whites?
trab first
Remember a notched nerve is likely problematic
study had no standard photos for ONH eval
What are risk factors for ALT failure according to AGIS?
younger, higher IOP
What are risk factors for trabeculectomy according to AGIS?
young age, higher IOP (esp increase of 10 mmHg), DM, post-op complications
What did AGIS show in terms of VF changes?
significantly worse VF change in 17.5 IOP than <14 IOP and significantly less VF change with greater % of visits under 18 mmHg
What did AGIS find happens if all visits are under 18 and low initial IOP?
minimal (almost no) VF progression
What are AGIS take homes?
decreasing IOP with ALT or trab reduces progression, AA respond better to ALT 1st, having trab does not keep patients from having positive effect from ALT (or SLT) and vice versa
What was the purpose of the CIGTS?
collaborative initial glaucoma treatment study, efficacy of trabeculectomy vs topical meds in initial glaucoma
What outcomes were measured in CIGTS?
QOL and objective measures
What were the CIGTS treatment arms?
medical and surgical arms with target IOP specific to patient, POAG, pigmentary and PXE
T/F patients had individualized VF scores and individual specific target IOPs in the CIGTS
true
What were the CIGTS med therapies?
meds, ALT once max meds attempted, trab, meds, trab w/ antimetabolite, meds
What were the CIGTS surgical therapies?
trab 5FU optional, ALT, Meds, trab w/ antimetabolite, meds
What was the CIGTS QOL survey named?
symptom impact glaucoma score
What was the average entering IOP of the CIGTS?
27 mmHg
What was different about the patients in the CIGTS?
40% AA and they tended to average 5 years younger
What were the CIGTS results?
both protocols effective on IOP, HVF loss initially greater in Sx arm but equal at 5 years, acuity loss greater in surgical tx, cataract development greater in surgical tx
What were the QOL results in CIGTS?
comfort and visual scores worse in the surgery arm with systemic symptoms worse in med arm
What is the CIGTS takehome?
medical therapy is equivalent to surgical therapy in GLC HVF changes, must consider S/E and complications
What is the purpose of the EMGT?
evaluate effect of immediate glaucoma surgical therapy vs monitoring on glaucomatous progression in newly diagnosed and previously untx
Where did the EMGT take place?
sweden, nearly 100% caucasian
What was the EMGT protocol?
POAG/NTG/PXE, reproducible HVF defects in at least one eye, acuity better than 20/50, IOP under 30, only mild cataracts
What were the study arms in the EMGT?
monitor and treatment with 360 ALT and betaxolol BID , follow yo in 3 months
What did the EMGT do if IOP was above 35 in controls or 25 in treated?
add latanoprost qhs
What were the EMGT IOP results in treated group?
mean reduced from 20 to 15 (25%), greater % reduction in IOP over 21 than below
What were the EMGT IOP results in the control group?
20 mmHg maintained well
What was the EMGT progression overall?
62% untreated and 45% treated
What was the median time to progression in the EMGT?
48 months in controls and 66 months in treated
What complaints were more common in the treated group in EMGT?
cataract and minor ocular comfort complaints
T/F progression is the rule
true, our goal is to slow progression and improve QOL
What are two important EMGT stats?
treatment reduced risk of progression 50% AND each 1 mmHg reduction leads to a 10% decrease in risk
What factors for progression were found in EMGT?
higher IOP, increased age, worse MD on HVF, exfoliation, bilateral disease, disc hemes
What is the EMGT take home?
treatment of GLC by reducing IOP reduces glaucomatous progression from 62% to 45%
How are age and VF related?
VF progression increased with age; AGIS 30% increase in 1 dB progression every 5 years; CIGTS 35% increase in 3.0 dB progression in 10 years; EMGT 51% increase in VF progress above 68 years old
