Diabetic Retinopathy, Macular Degeneration, Vision, Subnormal
Conditions
Keywords
Diabetic Macular Edema, Diabetic Retinopathy, Macular Edema, Photocoagulation, Psychophysical Testing, Stiles-Crawford Effect
Brief summary
The purpose of this study is to evaluate possible mechanisms of central visual loss in patients with diabetes mellitus. The visual loss of interest to be investigated is that associated with macular edema (prior to and following laser photocoagulation treatment) and that associated with panretinal photocoagulation. The evaluation will be performed with psychophysical testing, i.e., static perimetry and contrast sensitivity function. Of particular interest, the mechanisms of visual loss associated with macular edema (prior to and following laser photocoagulation) will be further investigated. Photoreceptor-mediated visual loss will be assessed by measurements of the Stiles-Crawford effect. Visual loss mediated by post-receptoral retinal changes will be assessed by measuring the Westheimer spatial desensitization/sensitization effect.
Detailed description
The purpose of this study is to evaluate possible mechanisms of central visual loss in patients with diabetes mellitus. The visual loss of interest to be investigated is that associated with macular edema (prior to and following laser photocoagulation treatment) and that associated with panretinal photocoagulation. The evaluation will be performed with psychophysical testing, i.e., static perimetry and contrast sensitivity function. Of particular interest, the mechanisms of visual loss associated with macular edema (prior to and following laser photocoagulation) will be further investigated. Photoreceptor-mediated visual loss will be assessed by measurements of the Stiles-Crawford effect. Visual loss mediated by post-receptoral retinal changes will be assessed by measuring the Westheimer spatial desensitization/sensitization effect.
Interventions
None listed
Sponsors
National Eye Institute (NEI)
Eligibility
Sex/Gender
ALL
Healthy volunteers
No
Inclusion criteria
Patients with diabetic retinopathy that has not been previously treated are eligible for the study. Patients who have had laser photocoagulation (either focal or scatter) are not eligible.
Countries
United States
Outcome results
None listed