Abstract
Purpose: :
To explore the macular cone photoreceptor structure and correlate with the photoreceptor layer in Optical Coherence Tomography (OCT) and a relative conservation of VA in patients with stargard desease
Methods: :
Higth resolution images of the macula were obtained with Adaptive Optics in patients with stargard desease between 12 and 40 years old ,they underwent completed ophthalmic examination including best corrected visual acuity on ETDRS, chart slit lamp ,autofluorecence ,fluorecein angiography (HRA2 Heidelberg ,Germany) ,Spectral Domain Optical Coherence (SD-OCT)and electroretinogram The AO device corrects ocular wavefront aberrations (OWAs)in closed-loop operation at 10Hz,based on a 52-actuator electromagnetic deformable mirror and a 1024 lenslet Shack -Hartmann sensor(Imagine Eyes,France).Each acquisition provides a 20 consecutives images. Ten of them were averaged and digitized to produce an enhanced final image. AO images werethen analysed and compared with visual fonction , autofluorescence images and spectral optical coherence tomography scans.
Results: :
Most of AO images revealeted increased cone spacing with irregular packing centrally in macular area and preserved in periphery and near the optic nerve. we distinguished 2 differents aspects .Aspect 1 showed central atrophy area in autofluorecence and this was also associated with disruption or loss of the reflective band at the photoreceptor inner segment and outer segment junction in SD-OCT, correlated with the de loss VA(1/10) and the absence of the overlying typical cone mosaic in AO. Therefore the second aspect showed central atrophy in autofluorecence in young patient with 12 years old, inner retina layer had disappereared on SD-OCT when VA was still fair ( 8/10) and cones mosaic in this area were visualized but abnormally large and spaced from each other
Conclusions: :
As a new technology,AO allows more precision of structural alterations of the retina, here AO has demonstrated that despite loss of RPE, some cones could survive and the interruption of the photoreceptor layer does not correspond to probably to the total loss of photoreceptors. Clinical used of AO will provided more information between ,the presence of photoreceptors in macular desease and to a possible correlation with age and genetics
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • photoreceptors • genetics