Non-familial occult macular dystrophy.
To present a series of patients who have poor central vision with normal funduscopic examination, fluorescein angiograms, and full field electroretinograms but significantly reduced multifocal electroretinographic responses most of whom are unaware of a family member similarly affected. Patients were evaluated clinically and with the use of visual field testing, fluorescein angiography, full field electroretinography, VERIS Multifocal Electroretinographic testing (MFERG), which along with focal electroretinography is currently the only objective method of detecting these localized retinal dysfunctions, and Optical Coherence Tomography (OCT) where possible. Nine patients (18 eyes) referred for evaluation of undiagnosed poor central vision were found to have abnormal multifocal ERG findings affecting all or part of the central portion of the test field. Funduscopic examination, fluorescein angiography, and full field electroretinography were all normal. These patients each reported a long history of poor vision with little if any clinical progression. There were no family members reported to have the same condition although a few were reported to have poor vision and only one of the patients had a sibling with decreased vision. At the time of their first examination patients ages ranged from 13 to 53. Although there is little evidence that the condition observed in these patients is inherited, all reported early onset often in childhood. Previous reports by Miyake and co-workers have described Occult Macular Dystrophy condition as an inherited macular dystrophy characterized by progressive macular dysfunction. In the present series there is little historical evidence of progression or of inheritance. Based on this data, Occult Macular Dystrophy may in fact represent more than one condition with multiple etiologies. Several etiologies are considered.