Evaluation of Visual Acuity Measurements in Eyes with Diabetic Macular Edema

Protocol Status: Currently Enrolling Patients

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A. Study Objective

The primary objectives of the study are as follows:

• Compare visual acuity results obtained using corrective lenses based  on the results of an autorefraction  with the results of acuity testing using corrective lenses based on the DRCR.net manual refraction protocol
• Determine the reproducibility of E-ETDRS visual acuity measurements in subjects with center involved diabetic macular edema at multiple centers
  

B. Major Eligibility Criteria

• Age >=18 years
• Diagnosis of diabetes mellitus (type 1 or type 2)
• At least one eye has each of the following:
  • OCT central subfield thickness >=250 microns (OCT must have been performed within 21 days of enrollment)
  • Visual acuity better than 20/400 (letter score >=19)
  • If decreased vision is present, it must be primarily due to DME in the investigator's opinion

•  Able and willing to provide informed consent

C. Summary of Study Protocol

 The study will include approximately 300 subjects with center involved diabetic macular edema (DME) (central subfield >=250 microns) in at least one eye. Recruitment will continue until there are at least 100 eyes with center involved DME in each of three visual acuity stratum: >=20/32 (letter score >=74), 20/40-20/80 (letter score 73-54), and 20/100-20/400 (letter score 53-19) that have been successfully autorefracted. Two E-ETDRS acuity tests will be completed using a DRCR.net protocol refraction and one E-ETDRS acuity test will be completed using a refraction from a commercially available autorefractor. The order of the refractions and testing will depend on whether the subject is participating in another DRCR.net protocol. Whenever possible, the visual acuity technician will be masked to the source of the refractions. All E-ETDRS acuity tests will be measured first in the right eye followed subsequently by the left eye. There will be a 5 minute break between tests.