Evaluation of Doxycycline Verses Placebo for the Treatment of Severe Nonproliferative or Mild or Moderate Proliferative Diabetic Retinopathy
Condition: Diabetic Retinopathy
MeSH terms: Retinal Diseases; Diabetic Retinopathy
Intervention: doxycycline monohydrate; placebo
Intervention description: 50mg once daily for 24 months; placebo taken once daily for 24 months
Intervention MeSH terms: Doxycycline
Phase: Phase 2
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Enrollment: 30.0
Sex: All
Minimum age: 18 Years
Healthy volunteers: No
Keywords: diabetic retinopathy; diabetes; diabetic eye studies; neovascularization

Summary:

      This 24 month randomized research study will evaluate whether doxycycline can 1) slow the
      deterioration or improve retinal function and/or 2) induce regression, or slow progression,
      of diabetic retinopathy in participants over 18 years of age with type 1 or type 2 diabetes
      with severe non-proliferative or early proliferative diabetic retinopathy.
    

Eligibility criteria:

        Inclusion Criteria:

          -  age ≥ 18 years old

          -  diagnosis of type 1 or type 2 diabetes mellitus

          -  have a hemoglobin A1c less than 11% at pre-qualification visit

          -  able and willing to give informed consent

          -  best-corrected ETDRS visual acuity in study eye ≥ 49 letters (20/100)

          -  severe non-proliferative diabetic retinopathy (ETDRS level 53E) or retinal and/or
             optic disk neovascularization less than the "high-risk" characteristics defined by the
             Diabetic Retinopathy Study (ETDRS level61- 65), and in whom panretinal
             photocoagulation is not imminently required in the ophthalmologist's judgment

          -  able to perform reliable visual field and dark adaptation testing

          -  central subfield thickness on OCT of ≤ 275microns

          -  foveal fixation present in each eye (assessed by fundus photography using an internal
             fixation pointer or assessed by the investigator)

          -  media clarity and pupil dilation sufficient for high-quality fundus photographs and
             fluorescein angiograms

        Exclusion Criteria:

          -  high-risk neovascularization in study eye

          -  prior panretinal photocoagulation in the study eye

          -  focal/grid laser photocoagulation in the macula within the past 15 weeks in the study
             eye

          -  intraocular pressure > 22mmHg by Goldmann Tonometry in the study eye

          -  history of pars plana vitrectomy in the study eye

          -  vitreous or pre-retinal hemorrhage in the study eye

          -  systemic or intravitreal anti-VEGF agent to the study eye or the fellow eye within the
             past 3 months

          -  peribulbar steroid injection to the study eye or the fellow eye within the past 6
             months

          -  intravitreal triamcinolone acetonide to the study eye within the past 4 months

          -  expectation by the investigator that retinal photocoagulation or other treatment for
             diabetic retinopathy (e.g. focal/grid laser to study eye, intravitreal triamcinolone
             acetonide to study eye, intravitreal anti-VEGF agent to study or fellow eye,
             ruboxistaurin or systemic anti-VEGF agent for diabetic macular edema) will be
             administered in the subsequent 24 months

          -  an ocular condition (other than diabetes) is present in the study eye that, in the
             opinion of the investigator, might alter visual acuity during the course of the study
             (e.g. retinal vein occlusion, uveitis or other ocular inflammatory disease,
             neovascular glaucoma, Irvine-Gass Syndrome, etc)

          -  anticipated need for cataract surgery in the study eye in the subsequent 24 months in
             the opinion of the investigator

          -  history of major ocular surgery (including cataract surgery, scleral buckle, any
             intraocular surgery, etc) in the study eye within prior 6 months or anticipated within
             the subsequent 24 months following randomization

          -  aphakia in the study eye

          -  history of YAG capsulotomy performed in the study eye within 2 months prior to
             randomization