Visual Acuity Changes in Patients With Leber Congenital Amaurosis and Mutations in CEP290
ABSTRACT OBJECTIVE To evaluate changes in visual acuity (VA) over time in patients with Leber congenital amaurosis (LCA) and mutations in the CEP290 gene. METHODS Visual acuity was determined at the initial and most recent visits of 43 patients with LCA and CEP290 mutations. The main outcome measures included the best-corrected VA at the initial and most recent visits, as well as the correlation between age and VA. RESULTS At the initial visit, 14 patients had measurable chart VA in the better-seeing eye, 25 patients had nonmeasurable chart VA, and 4 young patients did not have VA assessed. At the most recent visit, 15 patients had measurable chart VA and 28 had nonmeasurable chart VA. The average interval between the 2 visits was 10.4 years (range, 2-47 years). For patients with measurable chart VA, the median logMAR value at the initial visit (0.75; range, 0.10-2.30) and at the most recent visit (0.70; range, 0.10-2.00) did not differ significantly (P > .05). There was no significant relationship between VA and age. CONCLUSIONS Patients with LCA and CEP290 mutations had a wide spectrum of VA that was not related to age or length of follow-up. Severe VA loss was observed in most, but not all, patients in the first decade. These data will help clinicians provide counseling on VA changes in patients with CEP290 mutations and could be of value for future treatment trials.
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ABSTRACT: Mutations in the CEP290 (cilia-centrosomal protein 290 kDa) gene in Leber congenital amaurosis (LCA) cause early onset visual loss but retained cone photoreceptors in the fovea, which is the potential therapeutic target. A cone-only mouse model carrying a Cep290 gene mutation, rd16;Nrl-/-, was engineered to mimic the human disease. In the current study, we determined the natural history of retinal structure and function in this murine model to permit design of pre-clinical proof-of-concept studies and allow progress to be made toward human therapy. Analyses of retinal structure and visual function in CEP290-LCA patients were also performed for comparison with the results in the model. Rd16;Nrl-/- mice were studied in the first 90 days of life with optical coherence tomography (OCT), electroretinography (ERG), retinal histopathology and immunocytochemistry. Structure and function data from a cohort of patients with CEP290-LCA (n = 15; ages 7-48) were compared with those of the model. CEP290-LCA patients retain a central island of photoreceptors with normal thickness at the fovea (despite severe visual loss); the extent of this island declined slowly with age. The rd16;Nrl-/- model also showed a relatively slow photoreceptor layer decline in thickness with ∼80% remaining at 3 months. The number of pseudorosettes also became reduced. By comparison to single mutant Nrl-/- mice, UV- and M-cone ERGs of rd16;Nrl-/- were at least 1 log unit reduced at 1 month of age and declined further over the 3 months of monitoring. Expression of GNAT2 and S-opsin also decreased with age. The natural history of early loss of photoreceptor function with retained cone cell nuclei is common to both CEP290-LCA patients and the rd16;Nrl-/- murine model. Pre-clinical proof-of-concept studies for uniocular therapies would seem most appropriate to begin with intervention at P35-40 and re-study after one month by assaying interocular difference in the UV-cone ERG.PLoS ONE 03/2014; 9(3):e92928. DOI:10.1371/journal.pone.0092928 · 3.53 Impact Factor