The Advanced Glaucoma Intervention Study was a multicenter randomized clinical trial that compared two surgical treatment sequences for advanced glaucoma that had failed medical management. It involved 789 eyes of 591 patients followed over 13 years. The study found that an initial trabeculectomy resulted in greater IOP reduction than initial ALT. Maintaining an IOP of less than 18 mm Hg significantly reduced visual field progression compared to higher IOP levels. The risk of failure after the first intervention was higher for blacks compared to whites in the trabeculectomy-then-ALT sequence but lower in the ALT-then-trabeculectomy sequence.

1. ADVANCED GLAUCOMA
INTERVENTION STUDY
SIVATEJA CHALLA

2. 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

3. • 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

4. AGIS 1

5. 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?

6. 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

7. • Visual acuity, gonioscopy, and fundoscopy were
each assessed 1X
• visual field testing was 2X, and
• IOP was assessed 3X at baseline.

9. • 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.

13. AGIS 2

14. SCORING 1 - 20

15. 1.SCORE 1
if 4 or >4 points depressed >12 db add +1

16. 2.each hemifield (23 points)
SCORE Cluster with
depressed test
sites
1 3-5
2 6-12
3 12-20
4 >20

17. 3.THRESHOLD
SCORE CRITERIA
5 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

18. 4
So can consider 2 points
One should be <12 db
ADD +1

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

20. Reliability rating

22. AGIS 3

23. • 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

25. But... DISC HGE

26. AGIS 4

27. • 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

28.  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

29. A-T-T T-A-T

30. AGIS 5

31. FAILED ALT + TRAB (vs) TRAB
(119 EYES) (379 EYES)
Data on bleb encapsualtion collecetd at dx,3m and 6m later

33. Stastistically not significant

34. BUT….
Encapsulation of bleb Males >> Females

35. AGIS 6

36. TYPE Type 1
cataract
Type 2 cataract
BCVA better than 6/15 Worse than 6/15

38. AGIS 7

39. • 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

40. • 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.

41. MOST IMPORTANT…
IOP LESS FIELD PROGRESSION LESS

42. AGIS 8

43. ???

46.  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 %

47. So………

48. AGIS 9

49. A-T-T vs T-A-T

50. 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

51. • 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.

52. AGIS 10

59. AGIS 11

60. 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 complications
1. Elevated IOP
2. marked inflammation

61. AGIS 12

62. 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??

63. AGIS 13

64. A-T-T T-A-T

65. AGIS 14

66. • 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%

69. 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.

70. THANK YOU