Primary Outcome Measures:
- Proportion of subjects with improvement of 15 or more letters of best corrected visual acuity from baseline to 3 months on an Early Treatment Diabetic
Retinopathy visual acuity chart measured at 4 meters [ Time Frame: 3 months ] [ Designated as safety issue: No ]
Secondary Outcome Measures:
- Retinal changes on ophthalmoscopy [ Time Frame: 3 months ] [ Designated as safety issue: No ]
- Retinal thickness measured by Optical Coherence Topography (OCT) [ Time Frame: 3 months ] [ Designated as safety issue: No ]
- Fluorescein leakage on fluorescein angiography [ Time Frame: 3 months ] [ Designated as safety issue: No ]
- Complications related to drug or its administration [ Time Frame: 12 months after last injection ] [ Designated as safety issue: Yes ]
This study is a randomized, interventional case series. A total of 10 patients, seen in the Retina Division of the Wilmer Eye Institute, will be enrolled. Subjects will be randomized to either 0.3 mg or 0.5 mg intravitreal injections of ranibizumab. Patients with IPT with macular edema documented on optical coherence tomography (OCT) but no choroidal neovascularization will be eligible for this study. Exclusion criteria will include other forms of retinopathy, active intraocular inflammation, history of poor vision due to conditions other than IPT in either eye, and known hypersensitivity to humanized monoclonal antibodies. After obtaining informed consent, the patient will undergo baseline assessment including best-corrected ETDRS visual acuity, ocular examination, color fundus photography, fluorescein angiography, and OCT. If both eyes are eligible, the study participant and investigator will choose which eye to be considered the study eye. The study eye will be assigned at random to receive an IVT dose of ranibizumab (0.3 mg/0.05 ml or 0.5 mg/0.05 ml) at the baseline, 1 month, and 2 month visits. Further monthly injections are at the discretion of the examiner, and may be withheld if there is lack of continued improvement (defined as lack of improvement of at least 5 letters on an eye chart compared with 2 previous consecutive visits or lack of decrease of the retinal center point thickness of at least 50 microns compared with 2 previous consecutive visits) or complete success (defined as visual acuity of 20/20 or better or retinal center point thickness <225 microns).