Work

Quantitative Autofluorescence as a Clinical Tool for Expedited Differential Diagnosis of Retinal Degeneration

Year: 2014

Type: article

Abstract: Homozygous and compound heterozygous mutations in ABCA4 are associated with multiple phenotypes, including bull’s-eye maculopathy (BEM).1 The BEM fundus patterning can also be conferred by other genes such as the retinitis pigmentosa guanosine triphosphatase regulator gene (RPGR), a gene that encodes a protein involved in trafficking to the outer segment.2 The carrier frequency of disease-causing mutations in ABCA4 is 1 in 20. Even after complete sequencing of the ABCA4 exons and adjacent intronic sequences in patients with a clinical diagnosis of Stargardt disease 1 (STGD1), 15% to 20% of cases still have only 1 identified disease-causing mutation and no mutations are found in 10% to 15% of individuals.3 Thus, the phenotypic and allelic variability of ABCA4-related disease remains a challenge. Due to reduced protein function, ABCA4 mutations trigger elevated accumulation of bisretinoid lipofuscin in retinal pigment epithelial cells. This increase is revealed in most but not all cases as augmented fundus autofluorescence (AF), the inherent AF of the retina that is emitted with 488-nm excitation.4 Using a standardized method for quantification of fluorescence intensities in fundus AF images (quantitative fundus AF[ qAF]), increased qAF levels have been observed in patients with STGD14 even at young ages and in fundus areas that qualitatively appear to be unaffected. Herein, we show that qAF is a clinical tool that may help in the management of inherited retinal diseases.

Source: JAMA Ophthalmology

DOI: 10.1001/jamaophthalmol.2014.4507