Safety and Efficacy of Ranibizumab for Diabetic Macular Edema

The primary objective of the study is to assess the ocular and systemic adverse events of ranibizumab (Lucentis)for DME (diabetic macular edema) following previous treatment with intravitreal bevacizumab (Avastin).

This is an open-label, Phase I/II study of intravitreally administered 0.3mg ranibizumab (Lucentis) in subjects with DME (diabetic macular edema) previously treated with intravitreal bevacizumab (Avastin) with a randomized comparative dosing strategy, monthly vs "treat-and-extend." Thirty patients total will be enrolled in the study, 15 in each group. This study will have a 1-year treatment period. The recruitment period will occur over 1 year with total potential study duration of 2 years.

Eligibility Criteria:
Inclusion Criteria:

* Subjects will be eligible if the following criteria are met:

  * Ability to provide written informed consent and comply with study assessments for the full duration of the study
  * Age \> 18 years
  * ETDRS best-corrected visual acuity of 20/25 to 20/320 in the study eye
  * Willing, committed, and able to return for ALL clinic visits and complete all study related procedures
  * At least 6 previous bevacizumab injections for diabetic macular edema in the last 12 months in the study eye.
  * At least 2 bevacizumab injections within 10 weeks and the most recent bevacizumab injection within 6 weeks of baseline study visits in the study eye.
  * Persistent foveal-involving diabetic macular edema based on presence of intraretinal and/or subretinal fluid by SDOCT in the foveal center at study entry in the study eye.

Exclusion Criteria:

Subjects who meet any of the following criteria will be excluded from this study:

* Pregnancy (positive pregnancy test) or lactation
* Premenopausal women not using adequate contraception. The following are considered effective means of contraception: surgical sterilization or use of oral contraceptives, barrier contraception with either a condom or diaphragm in conjunction with spermicidal gel, an IUD (intrauterine device), or contraceptive hormone implant or patch.
* Intravitreal steroid or periocular steroid treatment within 3 months of study entry in the study eye.
* Focal/grid laser photocoagulation treatment within 3 months of study entry in the study eye.
* Panretinal photocoagulation treatment within 3 months of study entry in the study eye.
* Prior vitrectomy in the study eye
* History of retinal detachment in the study eye
* Prior trabeculectomy or other filtration surgery in the study eye
* Active intraocular inflammation in either eye
* Active ocular or periocular infection in either eye
* Active scleritis or episcleritis in either eye
* History of any other retinal vascular disease (e.g., retinal vein occlusion, retinal artery occlusion) in the study eye.
* Coexistent retinal disease other than diabetic retinopathy (e.g., AMD (age related macular degeneration), inherited retinal disease) in the study eye.
* Intraocular surgery within 3 months of study entry in the study eye.
* History of corneal transplant or corneal dystrophy in the study eye.
* Significant media opacities in study eye which may interfere with visual acuity in the study eye.
* Participation as a subject in any clinical study within 3 months of study entry.
* History of allergy to topical iodine
* 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