Public Health Control
Strategies for Glaucoma:
What do we Need to Know?
Nathan Congdon, MD, MPH
Zhongshan Ophthalmic Center
Sun Yat Sen University
Guangzhou, China
ORBIS International
Financial interest
 No financial interest
An explosion of new knowledge about
glaucoma and other eye disease
Visual burden of glaucoma increasing
despite new knowledge
Number Blind and Vision Impaired in the U.S. Population Aged 40 and over
6,000,000
5,000,000
4,000,000
2000
3,000,000
2010
2020
2,000,000
1,000,000
0
Blind
Low Vision
All Vision Impaired
This talk
 Questions to ask:
– What model for glaucoma programs in areas of
limited resources?
– What do we need to know to implement these
programs well?
 Introduce ideas this session will focus on:
– ZAP and EAGLE studies, CREST program,
Aravind tube shunt
 Emphasis on Asia:
– Evidence of significant disease burden
– Availability of resources
A strategy for glaucoma in rural Asia:
Start in the clinics
 Clinic-based case-finding:
– Economic models1 suggest that population-based
approach is not cost effective
– Uncertainty about morbidity associated with largescale programs of PI for narrow angles
 Target is persons aged 40+ years presenting for
eye care, and who are at risk for BLINDNESS
from glaucoma
1 Burr JM, et al. The clinical effectiveness and cost-effectiveness of screening for open
angle glaucoma: a systematic review and economic evaluation. Health Technol
Assess 2007;11(41):iii-iv,ix-x,1-190.
A strategy for glaucoma in rural
Asia: Screening for narrow angles
 Gonioscopy, possibly
with van Herrick testing
as a “pre-screen”
 The GOOD
– Cheap (US$75 goniolenses
available in India)
– Still the gold standard, no
proof yet that other
modalities are better
 The BAD
– Highly dependent on
quality of training
– Cutoffs for intervention
are not well-defined
A strategy for glaucoma in rural
Asia: Screening for glaucoma
 Principal focus on
evaluation of the disc
– Emphasis on detecting
patients with severe
damage
– Very limited evidence for
utility of field testing in
persons without fieldtaking experience
– Post-operative evaluation
of the nerve in patients
with dense cataract
A strategy for glaucoma in rural
Asia: Treatment
 Strategy may differ
between urban and rural
settings:
– Glaucoma drops widely
available in urban China and
India for US$1 per bottle
– Barriers of opportunity cost,
transportation and
availability make long-term
medical therapy untenable in
most rural areas
– In these areas, surgical
therapy will likely
predominate
A strategy for glaucoma in Asia:
Integrate glaucoma into the eyecare system
 In areas of limited
resources, a “glaucoma
program” is not going to
make sense
 Similar equipment and
training should also
build capacity to care for
DR (for example)
 The patient may have
come 100 km, we have to
be willing to move 5 mm
from the optic nerve to
the fovea!
The knowledge gap
 What do we need to know in order to
scale up glaucoma treatment in Asia?
Treatment of narrow angles, ACG
 Any expansion of service
provision for persons with
narrow angles requires a
better understanding of the
risk-benefit ratio for available
treatments.
– What are the long-term
effectiveness of cataract
extraction versus PI for
NA/AC? (EAGLE, ZAP)
– What are
incidence/progression rates
of cataract, corneal
decompensation, visually
significant glare, RD after PI?
(ZAP)
The CREST Network:
Comprehensive Rural Eyecare Service
and Training
 A collaboration between
ORBIS International,
Zhongshan Ophthalmic
Center and ten rural, countylevel hospitals in Guangdong
Province
 Aim: To build capacity of
rural hospitals to provide
comprehensive eye care
(including both glaucoma and
DR)
 Platform for programmatic
research on management of
glaucoma and DR in rural
Asia
Current knowledge and attitudes about
glaucoma in rural China
 Focus Group studies of
doctors and patients in
rural Guangdong have
revealed widespread
mis-conceptions (Arch
Ophhalmol 2012;130:761-70 ):
– Glaucoma viewed as rare
– Highly-symptomatic
disease
 Thorough examinations
of angle and optic nerve
only done on rare
patients with obvious
symptoms
Research on physician training
 Change in practice
patterns:
– Goal is routine full exam
for ALL patients > 40
years
– Use of electronic medical
record network tying 10
rural hospitals to ZOC to
assess documentation of
key facets of glaucoma
exam:
• IOP
• Gonioscopy
• Optic nerve
– Before and after training
Research on physician training
 A study of rural physicians’ ability to detect glaucoma
damage in the optic nerve is also under way
 Testing before and after training using the GONE
Website:
– Jonathan Crowsdon, CERA, Australia
– Chinese-language version of website now exists
Research on patient education
 RCT of intervention to
increase uptake of
glaucoma examinations
in clinic:
– Videos made especially for
the project
 Key ideas:
– Glaucoma asymptomatic
– Need comprehensive exam
to detect un-suspected
disease
– Potential for severe,
irreversible vision loss if
wait for symptoms
Research on patient education
 Patients are unsatisfied
with vision after
glaucoma surgery:
“negative social
marketing”
– RCT of educational
intervention including
videos
– Explain purpose of
glaucoma surgery
– Prepare patients for
likelihood of blurred VA
– Outcome is post-op
satisfaction level,
willingness to recommend
surgery
Research on patient compliance
 Patient long-term
compliance with
recommended DR care
and post op glaucoma
visits is poor (Ophthalmology
2010;117:1755-62.)
– Funding from WDF to
create automated
cellphone SMS reminder
system
– Increases 6-month
compliance from 36% to
86% in peds cataract
(Ophthalmology in press)
– 95% of local rural
patients have access to cell
service
Future issues: Research on
glaucoma treatment
 Outcomes of
conventional surgeries
(trab, surgical PI) in this
setting
 Could inexpensive,
locally-made tube shunts,
ExPress valves etc. be
better-suited to rural
surgeons and lower
patient compliance?
 What is impact of this
limited, clinic-based
strategy on preventing
glaucoma blindness in
the population?
Conclusion
 Many knowledge gaps
still exist in our
understanding of
managing glaucoma in
areas of limited
resources
 Research can help to fill
these gaps, and in doing
so to improve the
effectiveness and
efficiency of programs