Abstract
Purpose: :
To correlate results of visual function (VA, central fields, mf ERGs) and retinal structure (with SD OCT) in patients with a wide spectrum of disorders of the outer retina.
Methods: :
100 randomly selected eyes of 100 patients with retinal disorders affecting the outer retina were clinically evaluated. SD OCTs were obtained in all cases with either the Topcon 3-D OCT, Zeiss Cirrus HD OCT or the Heidelberg Spectralis. Disorders include: rare congenital ones such as Lebers congenital amaurosis, complete and incomplete achromatopsia, rubella retinopathy; inherited disorders such as retinitis pigmentosa and cone dystrophy; rare acquired disorders such as acute zonal occult outer retinopathy (AZOOR), acute multi-focal placoid pigment epitheliopathy (AMPPE), plaquenil toxicity; common disorders such as drusen, geographic atrophy of the RPE, CNVM, central serous choroidopathy, macular holes and myopic degeneration.The IS/OS junction was classified as either normal, thin, discontinuous with gaps, disorganized or absent.
Results: :
In every eye with reduced VA, the IS/OS junction was abnormal under the foveal pit. In patients with RP but 20/20 VA, the IS/OS junction was present in the central 5 degrees from where it continuously tapered and then disappeared towards the periphery. In cone dystrophy, the IS/OS junction is missing in the central 5 degees but present in all other scan locations. Mf ERGs correlated well with the status of the IS/OS junction with two exceptions: In one case of early symptomatic AZOOR, the IS/OS junction was abnormal prior to mf ERG loss and in one case of early plaquenil toxicity, the mf ERG was abnormal prior to loss of the IS/OS junction.
Conclusions: :
In a previous study, the IS/OS junction or Photoreceptor Integity Line (PIL) has been reported to be normal in 500 consecutive eyes. In all cases studied here, the junction abnormality correlated well with tests of retinal function. Hence, the junction can be considered as a biomarker for photoreceptor integrity.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • imaging/image analysis: clinical • photoreceptors