Abstract
Purpose: :
To describe fundus autofluorescence (FAF) for the first time in patients with achromatopsia and to compare these findings with infrared (IR) imaging and the structural changes seen on spectral domain optical coherence tomography (SD-OCT).
Methods: :
Retrospective observational case series of 30 eyes of 15 patients with achromatopsia (ages 10-62 years) imaged with FAF, IR, and SD-OCT.
Results: :
All patients demonstrated similar findings in both eyes on all imaging modalities. In 13 of 15 patients FAF was abnormal. 12 of these patients had a hypofluorescent foveola, and 8 of these patients demonstrated a hyperfluorescent ring around the area of hypofluorescence. 1 patient showed speckled hyperfluorescent drusen-like deposits. On SD-OCT, 13 of 15 patients showed disorganization or loss of the inner segment/outer segment (IS/OS) junction. The diameter of IS/OS junction loss corresponded well with the inner margin of the hyperfluorescent ring on FAF. 9 of 15 patients also exhibited a hyper-reflective and thickened external limiting membrane. All patients with abnormal FAF demonstrated abnormal IR imaging. 4 of 15 patients were hyper-reflective centrally, and 8 of 15 patients had both hypo- and hyper-reflective features. The dark foveal area on IR imaging corresponded well with IS/OS loss on SD-OCT, and hyper-reflective areas corresponded well with choroidal hyper-reflectivity on SD-OCT imaging. In all, 13 of 15 patients exhibited IS/OS junction breakdown or loss, and 9 of these patients also demonstrated some degree of RPE atrophy demonstrated by choroidal hyper-reflectance.
Conclusions: :
Patients with achromatopsia exhibit hyperfluorescence more characteristic of progressive retinal diseases such as Stargardt disease. Although hyperfluorescence generally correlated well with IS/OS loss on SD-OCT, it was not universally seen in patients with structural breakdown, suggesting that the integrity of photoreceptors may be affected earlier than changes in the RPE. We observed a higher incidence of RPE atrophy and IS/OS loss at younger ages than had been previously reported and, to our knowledge, present the finding of a thickened, hyper-reflective ELM for the first time. In addition to SD-OCT and fundus biomicrosopy, we recommend IR imaging for routine examination in these patients because it is easy to perform and provides additional information to aid in diagnosis.
Keywords: degenerations/dystrophies • imaging/image analysis: clinical • retinal degenerations: hereditary