prp has been the mainstay for treatment...
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PRP has been the mainstay for treatment of PDR since the Diabetic Retinopathy Study Research Group reported its results in the 1970s
Those of us who have been in practice for more than two decades have had many patients with PDR who received PRP, resulting in stabilization of vision and retinopathy for years without further treatment.
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Loss of peripheral vision
Development of diabetic macular
edema
Difficulty with night vision, especially if
the patient receives the recommended
2,000–3,000 burns.
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As we have moved to treatment to
inhibit VEGF and away from focal/grid
laser for DME based on DRCR.net
Protocol I, we have noticed a reduction
in the progression of nonproliferative
diabetic retinopathy to PDR.
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Prompt PRP vs.
Ranibizumab + Deferred PRP for PDR Study
Supported through a cooperative agreement from the National Eye Institute and the National Institute of Diabetes and
Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services EY14231, EY14229, EY018817
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Participants meeting all of the following criteria:
• Age ≥18 years with Type 1 or type 2 diabetes
Study eye(s) meeting all of the following criteria (a participant can
have 2 study eyes):
• PDR
• No history of PRP
• Best corrected visual acuity letter score ≥24
(~Snellen equivalent 20/320 or better)
• Eyes with or without central-involved DME were eligible
Randomized, multi-center clinical trial (55 Sites)
Primary Objective: Compare the efficacy and safety of
PRP with that of intravitreous ranibizumab (0.5-mg in
0.05 mL) for proliferative diabetic retinopathy (PDR)
Is visual acuity using ranibizumab for PDR not
worse than treatment with PRP at 2 years?
Non-inferiority margin of 5 letters
Secondary Question Are there potential benefits of ranibizumab on:
Vision throughout follow-up (area under the curve)
Peripheral vision
Macular edema
Incidence of vitrectomy
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Baseline to
1 Year
1 Year to
2 Years
PRP group: Visits every 16 weeks*
Ranibizumab group: Visits every 4
weeks to assess for PDR treatment
Both groups simultaneously
evaluated for DME treatment
PRP group: Visits every 16 weeks*
Ranibizumab group: Visits every 4wk
to 16wk to assess for PDR treatment
Interval is extended if injections for
PDR and DME deferred (“Defer and
Extend”)
*Eyes with DME could be seen more frequently for DME treatment as needed.
6 initial injections q4 weeks
One exception: if no neovascularization (NV) at
4-month or 5-month visit, then injection withheld
Starting at 6-month visit:
Inject if NV improved compared with any previous 3
consecutive visits where injection given
Withhold injections if NV stable over previous 3
consecutive injections
After injection withheld, resume injections if NV
worsens
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Prompt PRP- Initial
1 to 3 sittings within 8 weeks of randomization
Standard laser initial full session = 1200 to 1600 burns
Automated pattern initial full session = 1800 to 2400
burns
Ranibizumab required for eyes with central
involved DME and vision loss at baseline.
If the size or amount of NV increased following
initial PRP, then additional PRP could be given.
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PRP Group
Additional PRP Overall
(N = 203)
Eyes given additional PRP
(after completing initial full PRP) 45%
Distribution of timing to additional PRP
From completion of initial full PRP:
median time to additional PRP ~7 months
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Ranibizumab Group
# of Ranibizumab Injections
Eyes With Baseline
DME
(N = 36)
Eyes Without
Baseline DME
(N = 133)
Prior to 1-year Visit (Max possible = 13)
Median 9 7
Mean 8.9 6.9
Prior to 2-year visit (Max possible= 26)
Median 14 10
Mean 13.3 10.1
Note: 97% of protocol-required injections for PDR were given
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Ranibizumab Group
Received PRP for PDR
Overall
N = 191
Received PRP* before 2 years 12 (6%)
*1 met failure criteria, 1 with Protocol Chair approval, 1
without Chair approval, 8 during vitrectomy (e.g., via
endolaser), and 1 by non-study physician
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18 Outlying values were truncated to 3 SD from the mean
-5
0
5
10
15
0 16 32 52 68 84 104
Me
an
Vis
ua
l A
cu
ity
Ch
an
ge
(Le
tte
r Sc
ore
)
Visit Week
19 Outlying values were truncated to 3 SD from the mean
-5
0
5
10
15
0 16 32 52 68 84 104
Me
an
Vis
ua
l A
cu
ity
Ch
an
ge
(Le
tte
r Sc
ore
)
Visit Week PRP Group N = 203
+ 0.2
N = 168
20 Outlying values were truncated to 3 SD from the mean
-5
0
5
10
15
0 16 32 52 68 84 104
Me
an
Vis
ua
l A
cu
ity
Ch
an
ge
(Le
tte
r Sc
ore
)
Visit Week
Ranibizumab Group PRP Group
N = 191
N = 203
+ 2.8
+ 0.2
N = 168
N = 160
2-Year Adjusted Mean Difference: +2.2 letters
95% Confidence Interval: (-0.5, +5.0)
(Meets pre-specified non-inferiority criterion: lower
bounds of the 95% CI of -0.5 letters was greater than
the non-inferiority limit of -5.0 letters)
21 Area under the curve (AUC) analysis: Pre-planned secondary outcome
-5
0
5
10
15
0 16 32 52 68 84 104
Me
an
Vis
ua
l A
cu
ity
Ch
an
ge
(Le
tte
r Sc
ore
)
Visit Week
Ranibizumab Group PRP Group
N = 191
N = 203
+ 4.5
-0.3
Adjusted Mean Difference over 2 years (AUC): +4.2
P-value<0.001
95% Confidence Interval: (+3.0, +5.4)
N = 168
N = 160
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0 16 32 52 68 84 104
Visit Week
Without “Baseline DME”
-4
-2
0
2
4
6
8
10
12
14
0 16 32 52 68 84 104 Me
an
Vis
ua
l A
cu
ity
Ch
an
ge
(Le
tte
r Sc
ore
)
Visit Week
With “Baseline DME”
Ranibizumab Group PRP Group
+2
+7.9
- 0.5
+1.8
N = 42 N = 33 N = 147
N = 46 N = 37 N = 155 N = 130
N = 126
*Outlying values were truncated to 3 SD from the mean
Mean Change in Visual Acuity
Stratified by Baseline DME
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Humphrey Visual Field
30-2 + 60-4
Ranibizumab
Group
(N = 58)
PRP
Group
(N = 57)
Cumulative Point Score Change from Baseline
Mean -23 -422
Difference (P-Value) 372 dB (P<0.001)
Mean Deviation Change from Baseline
Mean -0.08 -2.50
Difference (P-Value) 2.2 (P< 0.001)
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Ranibizumab
Group
PRP
Group
Mean Change (µm) -47 -3
Adjusted Difference (P-value) -45 µm (P < 0.001)
Eyes with “Baseline DME”
Mean Change (µm) -153 -48
Adjusted Difference (P-value) -54 µm (P = 0.006)
Eyes without “Baseline DME”
Mean Change (µm) -18 +10
Adjusted Difference (P-value) -31 µm (P < 0.001)
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2-Year Adjusted Difference: 19%
95% Confidence Interval: (10% to 28%)
P-value < 0.001
N = 155
N = 147
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Ranibizuma
b Group
(N = 191)
PRP Group
(N = 203) P-value
Any retinal
detachment 6% 10% 0.08
Neovascular
glaucoma 2% 3% 0.50
Iris neovascularization 1% 1% 0.96
Vitreous hemorrhage 27% 34% 0.09
Vitrectomy 4% 15% < 0.001
PDR = proliferative diabetic retinopathy
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Ranibizumab
Group
(N = 142)
Prompt PRP
Group
(N = 148)
P-
value
Fundus Photos Graded by Reading Center* 0.41
No PDR 35% 30% -
Regressed NV 23% 24% -
Active NV 42% 46% -
* Only includes eyes with active NV at baseline
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Diabetic Retinopathy Improvement:
Ranibizumab Group (Note: Cannot determine for PRP Group)
Ranibizumab
Group
2-Year Visit N = 142
Eyes improving 2 or more steps in DR
severity on fundus photos 47%
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Summary of Ranibizumab group results vs. PRP:
Mean change in VA from baseline to 2-years with
ranibizumab no worse than with PRP
Superior mean visual acuity over course of 2-years
(area under the curve analysis)
Superior mean visual field outcomes
Decreased occurrence of vitrectomies
Decreased development of central involved DME
PRP rarely given for failure or futility of ranibizumab
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Rates of endophthalmitis or other injection-
related serious adverse events were very
low
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Typically able to be completed in one or two visits
Often long-lasting effect requiring no additional treatment However, study suggests approximately 45% given
additional PRP after initial full PRP was completed
From completion of initial full PRP, median time to additional PRP ~7 months
May cost less than ranibizumab injections
No risk of endophthalmitis
No risk of systemic exposure to anti-VEGF
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Presence of DME may influence the relative benefit of ranibizumab over PRP
When DME is present and treatment with an anti-VEGF agent is planned, PRP may be unnecessary in most cases provided that the patient is expected to be compliant with follow-up
When DME is not present, ranibizumab is more effective than PRP in preserving central and peripheral visual function, on average, but cost, follow-up compliance, and patient preference need to be considered
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Anti-VEGF initially for three injections
followed by PRP for more long-term
stability?
This approach would require a lighter
amount of PRP, thus reducing the
adverse effects on peripheral vision and
development of DME.
Full PRP and still NVE?
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PRP effective for PDR over last 4 decades;
remains effective in 21st century
Ranibizumab for PDR is at least as good as
(non-inferior to) PRP for visual acuity at 2 years
Ranibizumab is an effective treatment alternative to
PRP for PDR
No substantial safety concerns for at least 2 years
Looking forward to the five-year results of this
important ongoing clinical trial.
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