Early signs of longitudinal progressive cone photoreceptor degeneration in achromatopsia
- 1Ophthalmology Group, School of Medicine, University of Leicester, Leicester, UK
- 2Molecular Genetics Laboratory, Institute for Ophthalmic Research, Department for Ophthalmology, University of Tuebingen, Tuebingen, Germany
- Correspondence to Professor Dr Irene Gottlob, Ophthalmology Group, School of Medicine, University of Leicester, RKCSB, PO Box 65, Leicester LE2 7LX, UK;
Contributors MGT and IG were involved in the design and conduct of the study. MGT, RJM and VS performed data collection. Data analysis was done by MGT, SK and IG. Data interpretation was done by MGT and IG. Preparation of the first draft of the manuscript was done by MGT, and review and approval of the manuscript were performed by RJM, VS, SK and IG.
- Accepted 13 June 2012
- Published Online First 11 July 2012
Aims To characterise longitudinal progressive retinal changes in achromatopsia.
Methods Ultrahigh-resolution spectral optical coherence tomography (Copernicus, 3 μm axial resolution) was used to obtain tomograms of the fovea from five children and three adults with achromatopsia. Each patient was scanned twice with a mean follow-up time of 16 months. Progressive changes in reflectivity at the inner segment/outer segment (IS/OS) junction, the central macular and outer nuclear layer thickness were analysed.
Results Younger patients (<10 years; patient 1–5) showed progressive morphological changes at the IS/OS junction between visits 1 and 2. However, older patients (>40 years; patients 6–8) did not have any changes in the retinal morphology between visits 1 and 2. In patients 1 and 2, IS/OS discontinuities (visit 1) developed into a hyper-reflective zone confined to the fovea (visit 2). In patient 3, the hyper-reflective zone (visit 1) progressed to form an IS/OS disruption and early formation of a small hypo-reflective zone (visit 2). Patients 4 and 5 had a hypo-reflective zone (visit 1) which subsequently increased in size (visit 2). There was a decrease in central macular and outer nuclear layer thickness between visits 1 and 2 in children.
Conclusions For the first time, we show progressive longitudinal changes in retinal morphology in achromatopsia. Early changes include subtle IS/OS reflectivity alterations. The dynamic retinal changes in younger patients provide evidence that it represents a progressive disorder, and implementation of gene therapy during the early stages of the disease may provide best prognosis.
- cone photoreceptors
- optical coherence tomography
- foveal hypoplasia
- optic nerve
- visual pathway
- visual pathway
- anterior chamber
- diagnostic tests/investigation
- field of vision
Funding The study was supported by the National Eye Research Centre (Grant No: RM61G0124 and RM61G0216), Ulverscroft foundation and the Deutsche Forschungsgemeinschaft (Grant No: DFG KO 2176/1-2).
Competing interests None.
Ethics approval Ethics approval was provided by University Hospitals of Leicester.
Provenance and peer review Not commissioned; externally peer reviewed.