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An Observational Study of the
Development of Diabetic Macular Edema
Following Scatter Laser Photocoagulation
Protocol
Status: Completed
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here to view protocol"
A.
Study Design
- Prospective,
multi-center nonrandomized treatment study
B.
Objectives
- To
determine the incidence and extent of macular edema following scatter laser
photocoagulation surgery using optical coherence tomography (OCT) in
eyes without macular edema prior to scatter laser photocoagulation.
- To
explore whether the incidence and extent of macular edema varies
according to the number of sittings included in the treatement regimen.
C.
Major Eligibility Criteria
- Age
>=18 years.
- Study
eye with (1) OCT central subfield thickness <= 299 microns and (2)
early proliferative or severe nonproliferative diabetic retinopathy for
which investigator intends to perform full scatter photocoagulation in
either 1 sitting or 4 sittings.
D.
Treatment
Study eyes will receive scatter photocoagulation given by one of the
following two regimens to be selected by the investigator at his/her
discretion:
- 1
sitting with a minimum of 1200 to a maximum of 1600 burns, with one burn
width separation of burns and scatter extending from the peripheral
arcades to beyond the equator.
- 4
sittings, each separated by four weeks (+4 days), with
approximately 300 burns in each of the first two sittings and
investigator judgment for number of burns for the third and fourth
sittings as long as the total for the four sittings is between 1200 and
1600 burns
E.
Duration of follow-up: 34 weeks
F.
Main Outcomes
Primary
- Retinal
thickening (measured with OCT).
Secondary
- Visual
acuity (measured with E-ETDRS).
G.
Sample Size: 150 eyes
H.
Schedule of Study Visits and Examination Procedures
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Study Visits
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0
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2-4 days
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4 wks
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8 wks*
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12 wks*
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17 wks
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34 wks
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E-ETDRS visual acuity
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Xa
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X
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X
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Xa
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Xa
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Fundus photos b
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7F
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3F
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OCT
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X
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X
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X
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X
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X
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Dilated Fundus Exam
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X
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PRP Treatment
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X
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X*
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X*
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X*
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HbA1c c
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X
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Blood pressure
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X
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*For patients in the 4-sitting group only (exam data not
collected at 8 or 12 weeks from the first sitting)
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a =
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includes protocol refraction.
E-ETDRS refers to electronic ETDRS testing using the Electronic Visual
Acuity Tester that has been validated against 4-meter chart ETDRS testing.
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b =
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post-treatment posterior pole (ETDRS field 2) and one
peripheral field photos will be taken on the day of the first PRP sitting.
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c =
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does not need to be repeated if HbA1c and lab normal
values are available from within the prior 3 months (at baseline, can be
performed within 3 weeks after enrollment).
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