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