Abstract
Purpose: :
To describe the neuroretinal changes in 6 patients (2 families) with autosomal cone-(rod)-dystrophy ADCRD segregating with p.R838C in GUCY2D.
Methods: :
In addition to a standard clinical examination the following inverstigations were performed: fundus autofluorescence imaging (FAF), optical coherence tomography (OCT), Ganzfeld ERG (ERG) and multifocal ERG (mfERG). GUCY2D was screened for mutations using direct sequencing.
Results: :
In both families, we identified a heterozygous p.R838C (c.2512C>T) mutation in GUCY2D. The age of the patients' ranged from 8 to 55 years. In young patients, fundus was unremarkable and visual acuity only slightly reduced. Ganzfeld ERG showed reduced b/a ratio in all. Cone ERG was clearly reduced at young age and non measurable in elder patients. MfERGs showed progressive deterioriation with age. FAF showed paracentral annular increased density early on, later progressive loss of the shadowing of the FAF by macular pigment, and finally absence of FAF in the macula. Loss of FAF shadowing was associated with increasing loss of photoreceptor nuclei (and fibers of Henle) in the center as visualized by Spectralis OCT. Outer retinal changes included progressive reduction of inner and outer segments.
Keywords: retinal degenerations: hereditary • retina: distal (photoreceptors, horizontal cells, bipolar cells) • genetics