Global Perspectives on
African Glaucoma
African Glaucoma Summit
Accra, 6 August 2010
Donald L. Budenz, MD, MPH
Professor of Ophthalmology,
Epidemiology, and Public Health
Bascom Palmer Eye Institute
University of Miami School of
Medicine
Overview
What is glaucoma?
What is the global burden of glaucoma?
What is the burden of glaucoma in
Africa?
What are the challenges to addressing
glaucoma in Africa?
What is Glaucoma?
A group of diseases characterized by
accelerated loss of optic nerve axons
Angle may be open or closed
IOP may be high or normal
Accompanied by clinical sign of cupping
of optic nerve and loss of peripheral,
then central, vision
Glaucoma: Global Burden
Most frequent cause of irreversible
blindness worldwide1
Second most frequent cause of
blindness worldwide after cataract1
Second highest DALY score for sense
organs behind cataract2
1. Resnikoff S, Pascolini D, Etya’ale D et al. Global data on visual impairment
in the year 2002. Bulletin World Health Org 2004; 82: 844-51.
2. WHO. World Health Report 2000. Annex Table 4. Accessed at
http://www.who.int/whr2001/2001/archives/2000/en/pdf/StatisticalAnnex.pdf .
Glaucoma: Global Burden
Resnikoff S, Pascolini D, Etya’ale D et al. Global data on visual impairment
in the year 2002. Bulletin World Health Org 2004; 82: 844-51.
Glaucoma: Global Burden
Estimates
POAG + ACG
POAG Bilaterally
Blind
ACG Bilaterally
Blind
Total Bilaterally
Blind
2010
60.5 million
4.5 million
2020
79.6 million
5.9 million
3.9 million
5.3 million
8.4 million
11.1 million
Quigley and Broman, The number of people with glaucoma worldwide in 2010
and 2020Br J Ophthalmol 2006;90:262–7.
Burden of Glaucoma in Africa
WHO: Africa is disproportionately
affected by blindness1
OAG is the leading cause of irreversible
blindness in Africa1
In a clinic-based survey in Accra, 70%
of glaucoma was open angle2
1. Resnikoff S, Pascolini D, Etya’ale D et al. Global data on visual impairment
in the year 2002. Bulletin World Health Org 2004; 82: 844-51.
2. Herndon, L.W., et al., Survey of glaucoma in an eye clinic in Ghana, West Africa.
J Glaucoma, 2002. 11(5): p. 421-5.
OAG Prevalence by Age and
Region
Quigley and Broman, The number of people with glaucoma worldwide in 2010
and 2020. Br J Ophthalmol 2006;90:262–7.
Why so much Glaucoma?
People of African descent have at least
4X risk of POAG than non-Africans
Probably inherited/genetic
Prevalence of POAG:
Baltimore Eye Survey
1.29% in whites
4.74% in blacks (over 40 years of age)
4x likelihood of blindness in Blacks vs.
Whites
IOP, Race, and Glaucoma
35
Black subjects
(n=4674)
30
White subjects
(n=5770)
25
20
Prevalence
15
%
10
10
55
0
10
14
18
22
26
IOP (mm Hg)
Sommer A, et al. Arch Ophthalmol. 1991;109:1990-95.
30
34
Tema Eye Survey
Investigators
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Keith Barton
Don Budenz
Peter Egbert
Graham Hay-Smith
Leon Herndon
Winnie Nolan
Julia Whiteside
Staff
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Jagadeesh Bandi
Michaela Clemens
William Feuer
Hanna Kim
Faye Kragt
Pak Sang Lee
Sarah Mechta
Joyce Schiffman
Ghanaian Staff
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Shine Amaglo
Maureen Armarh
Steven Boakye
Frank Boateng
Patience Dadzie
Paulina Darkenu
George Wood
Consultants
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Stephen Akafo
Paul Foster
Joanne Katz
Harry Quigley
Alan Robin
James Tielsch
Reasons for Tema Eye Survey
Few comprehensive eye disease
surveys in Africa
Most are in rural populations focusing
on trachoma and onchocerciasis
Trend toward urbanization of population
in West Africa
May be highest prevalence of glaucoma
in the world
Tema
Major industrial center
Wide range of
ethnicities and income
levels (“Melting pot” of
Ghana)
Ease of transportation
Tema clinic
experienced in visual
field and photography
Tema Eye Survey: Purpose
To determine the prevalence of
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Blindness
Visual disability
Specific eye diseases such as glaucoma
in an urban, West African, adult (≥ 40)
population
To identify the gene for Primary Open
Angle Glaucoma in West African blacks
Study Population
5,500 Ghanaians age 40 or over
Life Expectancy
at birth 2010 = 61 yrs
Life Expectancy
at birth 2050 = 75 yrs
Methods: Sampling
Random sampling of clusters containing
400 – 600 voting aged people
38% of voting age people over age 39
(190 eligible subjects per cluster)
Require 30 – 40 clusters
MUNICIPALITY
TOTAL
MALE
FEMALE
Demographics & Estimate of Economic composition
ASHIAMAN
183,381
91,723
91,658
Densely populated/”shanty town”/low income
TEMA NEWTOWN
71,719
35,251
36,468
Densely populated/low income
TEMA COMM. ONE
38,352
18,671
19,681
Commercial (TCEC) mostly mid income w/ some low/few
high
ADENTA EAST
37,905
19,154
18,751
Residential-- predominately middle income
LASHIBI
36,836
18,767
18,069
Newer community/high income (parliamentarians)
TEMA COMM. TWO
31,866
15,476
16,390
Some commercial/Middle income residential
SAKUMONO
24,610
11,897
12,713
Some commercial/higher middle income
TEMA COMM. FIVE
17,452
8,427
9,025
Residential/middle and upper income
TEMA COMM. FOUR
16,544
8,167
8,377
Residential/middle class
TEMA COMM.
SEVEN
15,079
6,994
8,085
Residential/middle class
ASHALEY BOTWE
14,608
7,365
7,243
Developing area/densely populated/low-middle income
KPONE
13,701
6,815
6,886
Residential/low income
TEMA COMM.
EIGHT
12,792
5,916
6,876
Residential/upper middle class
TEMA COMM. NINE
10,520
5,053
5,467
Residential/upper middle class
KAKASUNANKA II
7,523
3,845
3,678
Population less dense/all economic levels/Volta/Ga/Ashanti
TEMA COMM.
THREE
6,730
3,187
3,543
Residential/upper class
OGBOJO
6,271
3,288
2,983
(near Accra)
TEMA COMM. SIX
5,863
2,919
2,944
“High-high” class
TEMA COMM.
ELEVEN
5,677
2,702
2,975
Upper middle class
BETHLEHEM
4,862
2,392
2,470
Low income
TOTAL
562,291
Comm 1
Informed Consent
Presenting Visual Acuity
Autorefraction (all subjects < 20/40)
Blood Pressure
FDT 5% screening exam
Flashlight Exam
Tonopen IOP X 2 and Pachmate CCT
Field Survey
Field Exam
Refer if
not 20/40 or
better after
manifest
refraction
Refer if fails
test either eye
twice – 2 or
more abnormal
spots
Refer if
IOP
>/= 21
Dilate both pupils with Mydriacyl 1%/Neosynephrine
2.5% (all subjects with deep angles)
Personal Interview
Optic Disc and Macula Photos
Notify of need
for exam if read
abnormal by
reading center
or unable to get
good pictures
Refer if
narrow
angle
Field Exam
Field Exam
Field Exam
ETDRS Visual Acuity
Clinic Survey
Area 1
Manifest Refraction by OD
(if VA < 20/40)
Blood Pressure
Area 2
Humphrey Visual Field
SITA 24-2
Comprehensive Eye Examination
Area 3
Gonioscopy
Area 4
Area 5
Dilate both pupils with Mydriacyl 1%/Neosynephrine
2.5% (all subjects with deep angles)
Digital Optic Disc and Macula Photos – Nidek 3Dx
STOP and
refer for PI if
closed or
occudable
angle
Clinic Exams
Clinic Exams
Nidek 3Dx Stereo Disc and
Fundus Photos
Results
Census 6,806
Field Exams 5,607
Response Rate 82.2%
Positive on field exam 1869
Clinic Exams 1538
Response Rate 82.2%
TES: Population
Region of Birth
Ashanti
Greater Accra
Eastern
North
Western
Brong Ahafo
Volta
Central
Upper East
Upper West
Ghana 2000
Census
20.3%
17.1%
10%
9.5%
10.4%
9.5%
8.1%
8.1%
4.5%
2.7%
TES
4.80%
29.30%
15.20%
4.40%
3.90%
0.60%
18.50%
14.70%
0.30%
0.20%
Prevalence of Glaucomatous VF
Defects (Irrespective Of Disc Readings)
Approx
VF
Defect
Total
Age
40-49
50-59
60-69
70-79
80-89
>=90
Total
260
2606
269
1589
241
864
158
397
49
120
7
31
984
5607
%
SE
upper CI
10.0%
0.6%
11.2%
16.9%
0.9%
18.8%
27.9%
1.5%
30.9%
39.8%
2.5%
44.7%
40.8%
4.5%
49.8%
22.6%
7.5%
37.6%
17.5%
0.5%
18.6%
Prevalence of Glaucomatous VF
Defects (Irrespective Of Disc Readings)
45,0%
40,0%
35,0%
30,0%
25,0%
20,0%
15,0%
10,0%
5,0%
0,0%
40-49
50-59
60-69
70-79
80-89
>=90
Prevalence of Glaucomatous Optic
Disc (Irrespective of VF Readings)
ABNL
Optic
Disc
Age
Total
Approx
%
SE
upper CI
10.1%
0.6%
11.3%
40-49
264
Total
2606
50-59
213
1589
13.4%
0.9%
15.1%
60-69
168
864
19.4%
1.3%
22.1%
70-79
92
397
23.2%
2.1%
27.4%
80-89
21
120
17.5%
3.5%
24.4%
>=90
5
31
16.1%
6.6%
29.3%
763
5607
13.6%
0.5%
14.5%
Prevalence of Glaucomatous
Optic Disc (Irrespective of VF
Readings)
30,0%
25,0%
20,0%
15,0%
10,0%
5,0%
0,0%
40-49
50-59
60-69
70-79
80-89
>=90
Age Specific Prevalence of
Glaucoma with Field and Disc
Changes
Age
Total
40-49
VF +
disc
defect
81
Total
2606
50-59
91
60-69
%
SE
Approx
upper
CI
3.1%
0.3%
3.8%
1589
5.7%
0.6%
6.9%
87
864
10.1%
1.0%
12.1%
70-79
50
397
12.6%
1.7%
15.9%
80-89
14
120
11.7%
2.9%
17.5%
>=90
2
31
6.5%
4.4%
15.3%
325
5607
5.8%
0.3%
6.4%
Prevalence of Glaucoma with
Disc and Field Changes
20,0%
18,0%
16,0%
14,0%
12,0%
10,0%
8,0%
6,0%
4,0%
2,0%
0,0%
40-49 50-59 60-69 70-79 80-89 >=90
Comparison with Other Studies
of People of African Descent
Survey (N of African Descent)
Prevalence*
Tema (5607)
5.8%
Kongwa (3268)
4.16%
South Africa (987)
3.8%
Baltimore (2395)
4.7%
Barbados (4709)
7.0%
St. Lucia (1679)
8.8%
*Not adjusted for age or glaucoma definition
What are the challenges to
addressing glaucoma in Africa?
Many people with glaucoma due to high
prevalence in Africans
Too few resources to care for them
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Too few ophthalmologists
Too little money for eye care (drops, visits,
surgery)
Other health problems causing more
morbidity and mortality demanding
resources first (Malaria, HIV, cataract)
What are the challenges to
addressing glaucoma in Africa?
Disorganized health care delivery
systems
Medications impractical and not
sustainable
African people have large optic nerves
with large physiologic cups making
diagnosis difficult
Glaucoma surgery has poor success
rates in people of African descent
Challenge
Despite seemingly overwhelming
challenges, we need to do our part to
save vision!