advanced glaucoma intervention study

ADVANCED GLAUCOMA INTERVENTION STUDY

SIVATEJA CHALLA

INTRODUCTION• multicentric, prospective, randomized study

• on advanced primary open-angle glaucoma patients (POAG) that have failed initial medical treatment.

• 11 clinical centers in the United States

http://pub.emmes.com/study/agi/index.htm

• 789 eyes of 591 Patients

• April 1988 and November 1992

• Follow-up is projected to continue until march 2001

• Results published accordingly in 14 parts

AGIS 1

OBJECTIVES…•What is the clinical course and what are the outcomes after current therapies?•How effective in preserving vision are two sequences of surgical treatments, one starting with ALT and the other with trabeculectomy? •What are the early and late complication rates? •Can factors be identified that predict outcome with sufficient accuracy to help the ophthalmologist in planning treatment for a patient?

Inclusion and exclusion• Age 35-80 years• POAG• IOP >18 MM hg• Study eye is on MMT• Study eye is treatable with

either ALT or trabeculectomy.• able to cooperate with study

procedures and able to perform tests reliably

• signs consent form

• congenital anomaly of the AC or angle

• secondary glaucoma• kidney dialysis.• Eyes that have undergone

gonioplasty• Eyes with PDR or severe

NPDR.• field loss attributed to a

nonglaucoma condition.• pupil diameter of less than 2

mm

• Visual acuity, gonioscopy, and fundoscopy were each assessed 1X

• visual field testing was 2X, and

• IOP was assessed 3X at baseline.

• Failure was defined as an eye on MMT that met the study’s eligibility criteria for elevated IOP,Visual field defects, and optic disc rim deterioration

• IOP was measured 1 and 4 weeks after each operation, and visual acuity ,visual fields ,and IOP were assessed 3 and 6 months after enrollment and then biannually thereafter. Data collection closed March 31, 2001.

AGIS 2

SCORING 1 - 20

1.SCORE 1

if 4 or >4 points depressed >12 db add +1

2.each hemifield (23 points)SCORE Cluster with

depressed test sites

1 3-5

2 6-12

3 12-20

4 >20

3.THRESHOLD

SCORE CRITERIA5 If half or more defective locations

in a hemifield are depressed 28 dB or more

4 27-24

3 23-20

2 19-16

1 15-12

4

So can consider 2 points

One should be <12 db

ADD +1

Remember…

The maximum possible score is 20 (2 for the nasal field and 9 for each hemifield).

Reliability rating

AGIS 3

• examine the differences at baseline in demographic, medical, and ophthalmic characteristics between blacks and whites enrolled

• Age blacks younger to whites• Systemic HTN blacks > whites• VF defects severity blacks > whites• IOP similar in both groups• Blacks were more hyperopic and had relatively fewer

disk rim hemorrhages than whites.• Concluded that POAG occurs at more younger age in

blacks than whites and progression is also fast

But... DISC HGE

AGIS 4

• Average percent of eyes with decrease of visual field (APDVF)• average percent of eyes with decrease of visual acuity (APDVA), • average percent of eyes with decrease of vision (APDV)

Observed every six monthly till seven years

IOP reduction TAT >> ATT failure of the first intervention ATT>>TAT black patients VF, VA, and DV are less for the ATT

sequence than for the TAT sequence throughout the 7 years.

white patients, VF, VA, DV favors the ATT sequence but only for the first year, after which it favors the TAT sequence through the seventh year

A-T-T T-A-T

AGIS 5

FAILED ALT + TRAB (vs) TRAB (119 EYES) (379 EYES)

Data on bleb encapsualtion collecetd at dx,3m and 6m later

Stastistically not significant

BUT….Encapsulation of bleb Males >> Females

AGIS 6

TYPE Type 1 cataract

Type 2 cataract

BCVA better than 6/15 Worse than 6/15

AGIS 7

• 6m f/u for six yrs• Observations :• early average IOP > 17.5 mm Hg had significant

worsening of visual field progression compared with eyes that had an IOP < 14 mm Hg

• IOP < 18 100% TIMES – no change in VF progression• IOP <18 50% times – significant VF deterioration• Eyes with an IOP of > 17.5 mm higher prevalence of

diabetes• Black patients were more likely to have diabetes

compared with white patients.

MOST IMPORTANT…

IOP LESS FIELD PROGRESSION LESS

AGIS 8

???

After first trab whether next intervention done or not increases risk by 78%

After trab no post op complications cataract formation reduced by 47 %

After trab post op complications cataract formation increased by 104 %

So………

AGIS 9

A-T-T vs T-A-T

A-T-T

• Blacks were at lower risk than whites of failure of first intervention

T-A-T

• Blacks were at higher risk than whites of failure of the first intervention

In both treatment sequences, the average number of prescribed medications was greater for blacks than whites

• 30% of black patients eyes and 39% of white patients eyes underwent a second intervention in the ATT sequence

• 18% of black patients eyes and 13% of white patients eyes in the TAT sequence.

AGIS 10

AGIS 11

Pre intervention factors(asso c failure rate more)

ALT• younger age • higher IOP

TRAB• younger age • higher IOP • diabetes

Post intervention factors(asso c failure rate more)

• Postoperative complications1. Elevated IOP2. marked inflammation

AGIS 12

sustained decrease of visual field (SDVF)

• Better baseline visual field in both treatment sequences

• Male gender• worse baseline visual acuity

in the ATT sequence• diabetes in the TAT

sequence

sustained decrease of visual acuity (SDVA).

• Better baseline visual acuity• older age• less formal education

RISK FACTORS??

AGIS 13

A-T-T T-A-T

AGIS 14

• To determine the least worsening of a visual field (VF) and the least number of confirming tests needed to identify progression of glaucomatous VF defects.

• Patients with advanced glaucoma, a single confirmatory test 6 months after a VF worsening indicates with at least 72% probability a persistent defect

• Confirmatory tests is increased from 1 to 2, the percentage of eyes that show a persistent defect increases from 72% to 84%

TAKE HOME MESSAGE• Interaction between race and treatment

sequence• A relationship between IOP and VF stability• Visual function improved after cataract

surgery• More cataracts after trabeculectomy• Race differences in the progression of

advanced glaucoma.

THANK YOU