Abstract
Purpose:
Occult macular dystrophy (OMD) is an inherited macular dystrophy with a progressive decrease of visual acuity but with essentially normal fundus. There are several reports of the cone photoreceptors in eyes with OMD obtained by adaptive optics (AO) imaging, but no specific feature has been reported. The purpose of this study was to determine whether common morphologic abnormalities can be detected by AO fundus camera in OMD patients
Methods:
Twenty-two eyes of 11 OMD patients were studied. All patients were diagnosed OMD by the BCVA, fundus examinations, full-field electroretinograms (ERGs), focal macular ERGs, multifocal ERGs, fluoresein angiography, fundus autofluorescence imaging, and spectral domain optical coherence tomography (SD-OCT). Their ages ranged from 20 to 69 years (mean 47±15 years) and consisted of 7 men and 5 women. Their decimal BCVA were ranged from 0.1 to 0.6. A mutation of RP1-L1 gene (R45W), one of the causative genes of OMD, was confirmed in 2 patients by genetic screening, and the others did not have this mutation. We obtained images of the central retina with the AO fundus camera (rtx1™, Imagine eyes, France) and compared them to those obtained from 30 healthy control eyes.
Results:
In the control eyes, a well-defined cone photoreceptor mosaic pattern was detected over most of the central retina. But in OMD patients, this pattern was not detected and numerous bright particles were detected randomly spread throughout the central retina on a blurred background instead. The size of particles was comparable to that of cone photoreceptors.
Conclusions:
The AO fundus images showed an absence of a normal cone photoreceptor mosaic pattern in the central retina of OMD patients. This supports the focal macular ERG and the SD-OCT findings of cone photoreceptor damage in the macular area. The numerous bright particles seen in all of the OMD patients appear to be one of characteristic features in the AO fundus images of OMD retina.
Keywords: 696 retinal degenerations: hereditary •
550 imaging/image analysis: clinical •
494 degenerations/dystrophies