Abstract
Purpose: :
to evaluate the anatomic and functional changes in patients with oculocutaneous albinism.
Methods: :
we analyzed two siblings: a child of 6 years and a girl of 16 years with oculocutaneous albinism (OCA); both were submitted to a complete ophthalmic examination, SD-OCT and Microperimetry. SD-OCT (Heidelberg Engineering, Germany) was performed in both patients to analyse the average foveal thickness. Microperimetry with analysis of retinal sensitivities and fixation patterns were performed using a MP-1 (NIDEK Technologies) with a red cross of 2° as the fixation target, white background illumination of 4 asb, Goldman III stimuli with a projection time of 200 ms, and a customized grid of 68 stimuli around 10° centered on the fovea. Because of poor cooperation, the child was submitted just to fixation study. Fixation patterns were classified according to Fuji et al.
Results: :
In the girl BCVA was 6/20 in the right eye and 8/20 in the left eye. Microperimetry revealed an unstable and poor central fixation in both eyes due to nystagmus and an average retinal sensitivities of 19.5 dB in both eyes. In the child, BCVA was 8/20 in the right eye and 6/20 in the left eye. Microperimetry revealed a stable and central fixation in the right eye and a relatively unstable and central fixation in the left eye. In both patients SD-OCT revealed absence of foveal pit, and preservation of the inner retinal layers and thickened fovea with a central thickness of 336 µm (Right Eye) and 338 µm (Left Eye) in the girl and 319 µm in both eyes in the child.
Conclusions: :
this study confirms all the typicals alterations of OCA and the importance of imaging techniques, such as SD-OCT and microperimetry, in the morpho-functional evaluation of this disease. In both patients, SD-OCT revealed absence of the foveal pit with preservation of the inner retinal layers. Nystagmus, another typical sign of OCA, although in different degrees, was present in both patients and altered the stability of fixation. In our opinion, Microperimetry is a very useful tool to evaluate visual function in patients with OCA and could be also very valuable to perform a rehabilitation program in the future.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • retinal degenerations: hereditary • low vision