Photoreceptor structure and function in patients with congenital achromatopsia.

Alfredo Dubra // Publications // Sep 21 2011

PubMed ID: 21778272

Author(s): Genead MA, Fishman GA, Rha J, Dubis AM, Bonci DM, Dubra A, Stone EM, Neitz M, Carroll J. Photoreceptor structure and function in patients with congenital achromatopsia. Invest Ophthalmol Vis Sci. 2011 Sep 21;52(10):7298-308. doi: 10.1167/iovs.11-7762. PMID 21778272

Journal: Investigative Ophthalmology & Visual Science, Volume 52, Issue 10, Sep 2011

PURPOSE To assess photoreceptor structure and function in patients with congenital achromatopsia.

METHODS Twelve patients were enrolled. All patients underwent a complete ocular examination, spectral-domain optical coherence tomography (SD-OCT), full-field electroretinographic (ERG), and color vision testing. Macular microperimetry (MP; in four patients) and adaptive optics (AO) imaging (in nine patients) were also performed. Blood was drawn for screening of disease-causing genetic mutations.

RESULTS Mean (± SD) age was 30.8 (± 16.6) years. Mean best-corrected visual acuity was 0.85 (± 0.14) logarithm of the minimal angle of resolution (logMAR) units. Seven patients (58.3%) showed either an absent foveal reflex or nonspecific retinal pigment epithelium mottling to mild hypopigmentary changes on fundus examination. Two patients showed an atrophic-appearing macular lesion. On anomaloscopy, only 5 patients matched over the entire range from 0 to 73. SD-OCT examination showed a disruption or loss of the macular inner/outer segments (IS/OS) junction of the photoreceptors in 10 patients (83.3%). Seven of these patients showed an optically empty space at the level of the photoreceptors in the fovea. AO images of the photoreceptor mosaic were highly variable but significantly disrupted from normal. On ERG testing, 10 patients (83.3%) showed evidence of residual cone responses to a single-flash stimulus response. The macular MP testing showed that the overall mean retinal sensitivity was significantly lower than normal (12.0 vs. 16.9 dB, P < 0.0001).

CONCLUSIONS The current approach of using high-resolution techniques to assess photoreceptor structure and function in patients with achromatopsia should be useful in guiding selection of patients for future therapeutic trials as well as monitoring therapeutic response in these trials.