“funnel” strategy: screening, diagnostics
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Transcript “funnel” strategy: screening, diagnostics
Manual small incision cataract
surgery (MSICS): opening the
door to a new strategy for
addressing blindness
Glenn Strauss MD
Mercy Ships
with thanks for contributions by James MacAllister, M.D.
First high quality alternative to
phaco
An elegant sutureless ECCE procedure
It is ideal for situations where high quality,
high volume output is desirable without
high-tech instrumentation or equipment
Provides an alternative to standard ECCE
when phaco is high risk.
Opens the door to new strategies
in patient care
Ideally utilized as part of a team system to
maximize efficiency as a single procedure
approach to cataract surgery
Increasingly being utilized as an alternative tool
for high risk cataracts
Integral part of a “funnel” strategy: screening,
diagnostics, perioperative care, and surgical care
Has provided a new paradigm to address the
problem of global cataract blindness
The funnel strategy
Utilizes key skills at each level of care
Maximizes use of individual strengths
Surgical yield in areas of low access is
approximately 15% of those being screened
Criteria based: Decreased vision, nl pupils,
clear cornea
If surgical goal is 3,000 cases, 20,000 will
need to be screened, 8,000 examined.
MSICS features:
Flexible enough to be used with a variety of
cataract pathologies
Quick, efficient surgery once mastered
Rapid recovery
Minimal postoperative corneal edema
• Minimal induced astigmatism (studies show
comparable to phaco)
No sutures to be removed late
Low cost per case
A brief review of the technique as
practiced on Mercy Ships
Anesthesia
Routine peribulbar or anterior conal blocktopical possible but less desirable
Lidocaine 2% 5cc alone usually sufficient because
of short case time
Orbital compression helpful but does not require
soft eye like ECCE
Routine prep and drape
Topical 5% betadine conj. drops and skin scrub,
isolate lashes
Adequate conjunctival/tenons
dissection and wet field cautery
May use flame cautery if only option
but avoid over cauterization
Dry carefully before scleral
dissection
Scleral incision
With fine toothed forceps hold limbal tissue and
create 7.5 mm “frown’’ incision 1.5 mm from limbus
at apex of the frown. 1/2 to 2/3 depth.
Initially it may be easier to make a simple linear
incision
Sclero-corneal tunnel
dissection
Carefully follow the curve of the globe, slicing anteriorly
approx 2 mm into clear cornea centrally
Take care to “straighten” the limbal junction angle
A 3 to 3.5 mm tunnel length (half the length of the
crescent blade)
Premature entry results in
iris prolapse
Tunnel button hole is easily
fixed with new tunnel plane
Sweep to each side to create an
8 to 8.5 mm internal opening
Tunnel size can be titrated to the
anticipated size of the nucleus
Paracentesis at 9 o’clock with 15 deg
blade- no anterior chamber
maintainer necessary
Useful for reforming chamber
Keratome entry at anterior most
extent of scleral tunnel
Sweep keratome left and right “floating” in
the tunnel to fully open. If done well,
chamber is maintained.
Consider supporting AC with viscoelastic
Careful 8 to 8.5mm “can opener” capsulotomy
after filling AC with viscoelastic. CCC may be
done for softer nucleus.
A
C
B
D
With capsulotomy needle inserted into
nucleus, “rock and roll”, rotating and lifting the
nucleus from the capsular bag
A
B
C
D
With lens loop, depress posterior lip of scleral
tunnel and allow nucleus to glide out through
the incision. (must be large enough)
Tunnel acts hydro dynamically
like a funnel
Nuclear material never contacts
endothelium
Facilitates increased efficiency of
nucleus removal
Improves safety in high risk cases
(trauma, zonular instability, partially
dislocated cataracts, hypermature
cataracts, previous surgery)
Gently depress post. lip of tunnel to milk
out remaining lens material while tilting the
globe by holding the limbus at 6 o’clock
Remove remaining cortex using suck and
wash approach (dragging cortex to center of
pupil and releasing).
Standard Simcoe is not ideal instrumentdesigned for limbal incision. Chamber
maintenance is dependant on making inner
opening the pivot point.
The eye is now ready for lens implantation.
Fill anterior chamber with methylcellulose or
air.
Insert IOL and remove methylcellulose. Inject
BSS to moderate pressure. AC should remain
formed. No conj closure needed.
Complete the operation with routine
antibiotics +/- steroid. Remove the
speculum by lifting out inferior blade first
Other techniques for MSICS
ACM
Fish hook
Plastic glide for nucleus
Phaco nightmare
Results
250
200
150
100
P re O p V is ion
50
P os t O p
V is ion
/3
0
/8
0
20
-2
0
/1
6
20
-2
0
0/
10
0
0
-2
0/
20
HM
CF
PL
0
Results
Number of
P atients
C hang e in vis ion
100
90
80
70
60
50
40
30
20
10
0
< -2 0+ /- 3-6 7-11 122
16
17- 22- 27+
21 27
C hang e in vis ion / L og MAR
lines
Pre and post op visual function
180
No of patients
160
140
120
100
80
60
40
20
0
Post-op
Pre-op
Average number of lines improved
Improvement of vision by age: 30 to 40
y/o success are primarily traumatic
cataracts.
25.0
20.0
15.0
10.0
5.0
0.0
0-30 30-40
50
60
Age of patient
70
80+
overall
* p<0.05
Reported success rates from developing countries
120
% of patients
100
80
60
>20/80
40
20
0
20/200-20/80
<2/200
Barriers to implementation
Cost: low cost does not mean NO cost
Local regulatory issues
Lack of clear, positive motivations for the
team and surgeon
Medical community resistance: MSICS is
gaining credibility
Ophthalmic corporate resistance: less
dependence on high tech equipment
Surgeon skills
For discussion: how to take advantage of
this approach for the benefit of South
Africa
Brief review of recent RAAB study
Eastern Cape
Rapid Assessment of
Avoidable Blindness in
Eastern Cape Province
of South Africa
S.Saravanan of
PRASHASA Consultants
On behalf of FHFSA
Summary
The all-age prevalence of blindness for
Eastern Cape Province of South Africa is
estimated to be 0.58%;
The all-age magnitude of blindness for EC
Province is estimated to be 38,354 people
out of a population of 6.57 million;
Avoidable causes of blindness accounted for
73.2% of blindness, 86.1% of severe visual
impairment and 85.7% of visual impairment.
Summary
Cataract (62.2%) and sequel related to
cataract extraction (1.2%) accounted for
63.4% of all causes of bilateral blindness;
Posterior segment disease is responsible
for 31% of bilateral blindness;
36.1% of people with bilateral cataract
VA<3/60 had surgery and 18.9% at
VA<6/18.
Results – Cataract Surgery
Coverage
Cataract surgical coverage: 36.1 % of
people with bilateral cataract blind
(VA<3/60) had surgery and 18.9 % at
VA<6/18;
Results – Cataract Surgery
Outcome
22 % of the 109 eyes that had undergone
cataract surgery had a poor outcome (i.e
VA<6/60) with best correction;
Best corrected, good visual outcome
(>6/18) was estimated as 64.2%;
109 eyes had cataract surgery with 79%
having an IOL implant.
Results – Cataract Surgery
99% of all surgeries performed were at
public health facilities;
19.3% were using spectacles after cataract
surgery.
KEY FINDINGS - Productivity
Demand and Supply mismatch. Number
of surgeries not enough to match
“incidence”.
Low surgical Productivity
CSR in Eastern Cape province = 1022
Required CSR = 4,000
“Unaware of treatment”(63.7%, SVI57.8%)