ranibizumab for treatment of persistent diabetic neovascularization assessed by wide-field imaging

Conditions: Proliferative Diabetic Retinopathy

Summary: 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 diabetic neovascularization.

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.

Eligibility criteria:
inclusion criteria: * 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 or exclusion. * 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. other considerations: * 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. exclusion criteria: * 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