Session Title: Imaging I
Session Date/Time: Friday 12/09/2014 | 11:00-13:00
Paper Time: 12:04
Venue: Boulevard D
First Author: : T.Duncker USA
Co Author(s): : S. Tsang W. Lee J. Zernant R. Allikmets F. Delori J. Sparrow
Quantitative fundus autofluorescence (qAF) and spectral domain optical coherence tomography (SD-OCT) were performed in patients with Bull’s-Eye maculopathy (BEM) to identify phenotypic markers that can aid in the differentiation of ABCA4- and non-ABCA4-related disease.
Prospective study in an academic referral center.
37 BEM patients (age range: 8-60 years) were studied. All patients exhibited a localized macular lesion and qualitatively normal appearing surrounding retina without flecks. AF images (30°, 488 nm excitation) were acquired with a confocal scanning laser ophthalmoscope equipped with an internal fluorescent reference to account for variable laser power and detector sensitivity. The grey levels (GLs) from 8 circularly arranged segments positioned at an eccentricity of ~7°- 9° in each image were calibrated to the reference, zero GL, magnification, and normative optical media density, to yield qAF. In addition, horizontal SD-OCT images through the fovea were obtained. All patients were screened for ABCA4 mutations with the ABCR700 microarray and/or by next generation sequencing.
ABCA4 mutations were identified in 22 patients, who tended to be younger (mean age: 21.9 ±8.3 years) than patients without ABCA4 mutations (mean age: 42.1 ±14.9 years). Whereas phenotypic differences were not obvious on the basis of qualitative fundus AF and SD-OCT imaging, with qAF the 2 groups of patients were distinguishable. Thus 20/22 ABCA4-positive patients had qAF levels above the 95% confidence interval of healthy controls whereas 13/15 ABCA4-negative patients had qAF levels within the 95% confidence interval of healthy controls.
The qAF method can differentiate between ABCA4- and non-ABCA4 related BEM and may guide genetic testing in a clinical setting.