Diabetic neovascularization refers to a type of diabetic retinopathy which is worsening by
the abnormal growth of blood vessels in the back of the eye, damaging the retina. The usual
treatment is a type of laser, called panretinal photocoagulation. One drawback is that the
amount of space within the eye for use of this treatment eventually has its limit, and
should not be used too near the part of the retina used for detailed vision (the macula).
In similar eye disorders, there are certain injectable medications called anti-VEGF
treatments which can slow down or stop this abnormal blood vessel growth. This study sought
to compare use of ranibizumab versus standard panretinal photocoagulation in treatment of
The purpose is to compare the efficacy of ranibizumab versus additional panretinal
photocoagulation on diabetic neovascularization that is persistent despite previous
treatment with panretinal photocoagulation. We hypothesize that ranibizumab intravitreal
injections would induce neovascular regression in similar or better fashion than
supplemental laser photocoagulation. Consented, enrolled subjects will either receive
open-label intravitreal injections of 0.5-mg dose of ranibizumab or additional panretinal
photocoagulation (up to 500 300-500 um laser spots) in a ratio of two-to-one (2:1) at the
beginning of the study period. ETDRS best-corrected visual acuity, contrast sensitivity,
and Optos color photography will be performed at enrollment, at weeks 1, 2, 3 and 4, and at
months 2, 3, 4, 5 and 6. The subjects will undergo fluorescein angiography utilizing the
Optomap FA (fluorescein angiography) system and optical coherence tomography (OCT) at
enrollment, at weeks 2 and 4, and at months 2, 3, 4 and 6. The subjects will be followed
for a 6-month period for stabilization, regression, or recurrence of neovascularization. In
addition, patients will be evaluated for occurrence of macular edema.
- Ability to provide written informed consent and comply with study assessments for the
full duration of the study
- Age 18 years or older
Patient related considerations:
- Patients with Diabetes Mellitus (Type I or II) are eligible. HgA1c will be evaluated
at the beginning of the study, but this value will have no significance in inclusion
- Patients will not be pregnant at enrollment and must provide evidence of the use of
two types of birth control while enrolled in the study.
- Patients will have no known sensitivity to ranibizumab or other anti-VEGF injections.
Disease related considerations:
- Patients will have diabetic neovascularization as seen on fluorescein angiography
that was previously treated with full (at least 1200 laser burns) panretinal
photocoagulation and that has persisted at least three months.
- There will be no evidence of ocular inflammation at enrollment.
- There is no restriction on patient's current medications or concomitant illnesses as
long as there is no interference with patient follow-up.
- Patients may not be enrolled in another clinical study or observational trial.
- There is no limitation on patient's institutional status as long as the patient is
able to participate in follow-up.
- Pregnancy (positive pregnancy test)
- Uncontrolled glaucoma on three medicines or more to control intraocular pressure
- Prior enrollment in the study
- Any other condition that the investigator believes would pose a significant hazard to
the subject if the investigational therapy were initiated
- Participation in another simultaneous medical investigation or trial