This study evaluates micro-vascular changes in patients with diabetes. Results of diseased retinas will be compared to healthy controls.

The prevalence of diabetes mellitus (DM) is increasing worldwide. Diabetic retinopathy is the most prevalent complication of DM and a leading cause of visual impairment due to closure of capillaries. High-resolution imaging techniques of the retina and its supplying vascular networks can allow novel insight to subtle changes that cannot be appreciated in standard fundus examination. In this study capillary changes of patients with different severity levels of diabetic retinopathy will be investigated with non-invasive imaging technology to better understand the process of disease progression.

Imaging will be done with Optical Coherence tomography (OCT) angiography as well as spectral domain OCT and ultra wide-field imaging.

Inclusion Criteria:

• Age ≥18 Participants can have 1 or 2 study eyes

Patient Group:

• Diabetes mellitus type 1 or 2
• Study eye with any DR severity level: no DR, mild NPDR, mod NPDR, sev NPDR, PDR

Exclusion Criteria:

• Substantial media opacities that would preclude successful imaging

  • Active intraocular inflammation (grade trace or above) in either eye like infectious conjunctivitis, keratitis, scleritis, endophthalmitis as well as idiopathic or autoimmune-associated uveitis in either eye
  • Structural damage to the center of macula in the study eye
  • History of prior panretinal photocoagulation
  • History of treatment with intravitreal agents over the prior 6 months
  • Macular edema involving the central subfield
  • Prior history of vitrectomy
  • Atrophy of retinal pigment epithelium, subretinal fibrosis, laser scar within foveal avascular zone (FAZ) or organized hard exudate plaques
  • Substantial non-diabetic intraocular pathology in the study eye including retinal vascular occlusion, retinal detachment, macular hole, choroidal neovascularization, macula dystrophies
  • Intraocular surgery (including cataract surgery, YAG laser capsulotomy) in the study eye within 3 months preceding Day 0, or history of corneal transplantation in the study eye
  • Uncontrolled glaucoma in the study eye (defined as intraocular pressure ≥ 25 mmHg despite treatment with anti-glaucoma medication)or history of glaucoma filtration surgery
  • Inability to obtain fundus images of sufficient quality to be analyzed and graded