Author: Carlos Plaza-Laguardia (Spain)
Co-authors: Amancia Mateos-Hernández, Isabel Sendino-Tenorio, Borja Errazquin-Aguirre, Esteban Pertejo-Fernández, Laura Monje-Fernández
Purpose
To describe the pathological findings of a very rare entity using the latest imaging technology available, in addition to the corresponding functional tests.
Setting/Venue
Complejo Asistencial Universitario de León.
Methods
Case report.
Results
61-year-old male who attended for a general check-up. He claimed to be asymptomatic, but was interested in knowing his functional visual status. The visual acuity of both eyes was normal (20/20), also the tonometric exploration as well as the anterior segment structures. Pupillary dilation was performed for fundus examination where an intense atrophy of the retina and choroid was found incidentally in both eyes (more intense in the right eye) clearly distributed along the venous arcades. An optical coherence tomography (OCT) was performed, and clearly the atrophy was observed, as well as an incipient internal retinoschisis in the macula of the right eye. The autofluorescence showed a paravenous hypoautofluorescence pattern, surrounded by a hyperautofluorescent line of progression that undoubtedly continued the first-order veins. The electroretinogram showed intensities and latencies within normality. The visual field showed a negative scotoma that simulates the distribution map of the venous arcades. Despite the diagnostic suspicion, and the fact that most cases are sporadic, a genetic study was requested for the only mutation discovered in this context in the CRB 1 gene, not being pathologic in this case.
Conlusions
The differential diagnosis of paravenous atrophies is extensive and complex. The overlap of the various entities that can be contemplated makes it difficult to ensure a diagnosis with total confidence. Autofluorescence, with the hyperautofluorescent progression line extending through the veins towards the nasal space, more visible in the green mode than in the blue one, and the normal electroretinogram responses were key to establishing the diagnosis of pigmented paravenous chorioretinal atrophy, ruling out other possibilities such as polar posterior annular choroidal dystrophy, acute zonal occult outer retinopathy or paravenous retinitis pigmentosa. Pigmented paravenous chorioretinal atrophy is a very rare disease with few cases described in the literature. The vast majority of patients present asymptomatic and maintain stable vision. The family history is usually irrelevant, the progression is very slow or non-existent and the involvement is asymmetric, from which it is deduced that it is a mainly acquired disease. However, McKay's group reported a variant in the CRB1 gene in a family with a history of dominant paravenous atrophy with variable expressiveness. The pathogenesis of this entity is not clear. Possibilities include a genetic and post-inflammatory origin, although degenerative, vascular and congenital etiologies have been proposed.
Financial Disclosure
I have no financial relations
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