Purchase this article with an account.
Wylie Tan, Yaiza Garcia-Sanchez, Laura Finkelberg, Tom Wright, Marsha Kisilak, Melanie Campbell, Carol Westall; Functional and Structural Cone Abnormalities in Adolescents with Type 1 Diabetes. Invest. Ophthalmol. Vis. Sci. 2012;53(14):371.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To identify biomarkers for Diabetic Retinopathy (DR) by examining the structure and function of the cone photoreceptor system in adolescents with Type 1 Diabetes (T1D), no DR or mild nonproliferative DR (NPDR). Aims: 1) To identify the retinal quadrants with greatest and least dysfunction using the multifocal electroretinogram (mfERG). 2) To examine cone density in areas identified in Aim 1 and other areas at similar eccentricities using Adaptive Optics Scanning Laser Ophthalmoscopy (AOSLO).
Patients with T1D, no DR or mild NPDR, and aged-matched controls were assessed for localized retinal function using the mfERG. The amplitude and implicit time (IT) of the first order responses were averaged over 4 quadrants, divided along the vertical and horizontal axes. Responses were compared between patients and controls to identify the quadrants with greatest and least dysfunction. A subset of these patients and controls underwent AOSLO imaging with a PSI multimodal AO instrument at 5° superior and 5° nasal and temporal. Images of the cone mosaic (2°x2°) were used to compare cone densities between and within groups.
Fifty-three patients (16±2 years old) and 47 controls (17±3 years old) underwent mfERG testing. Quadrant (Q) amplitudes and IT were compared between patients and control using Student’s t-tests (p=0.0125 for multiple testing). QIT in patients was delayed in the superior temporal (Q1, p=0.002), inferior temporal (Q3, p=0.005), and inferior nasal (Q4, p=0.003), but not in the superior nasal (Q2, p=0.028). There were no significant differences in Q amplitudes between patients and controls. Ten patients and 7 controls underwent AOSLO imaging. Eleven images (5 controls, 6 patients) of the superior temporal and 8 images (3 controls, 5 patients) of the superior nasal cone mosaic were taken. Qualitative assessment identified that cone densities of patients were lower than controls, with the greatest difference (significant at p=0.02) being a relative reduction in the superior nasal location.
Relative cone dysfunction was greatest in the superior temporal and least in the superior nasal quadrant in patients with diabetes compared with controls. Qualitative examination on the small number of patients and controls who underwent structural assessments showed that patients had a reduction in cone density at both the superior temporal and nasal quadrants, with a significant deficit in the nasal location.
This PDF is available to Subscribers Only