Macular dystrophy with protan genotype and phenotype studied with cone type specific ERGs.
Curr Eye Res
; 22(3): 221-8, 2001 Mar.
Article
en En
| MEDLINE
| ID: mdl-11462159
ABSTRACT
PURPOSE:
To determine the L- and M-cone driven ERG responses in a male patient with macular dystrophy and a protan phenotype.METHODS:
We measured large field ERG thresholds to stimuli which modulated exclusively the L- or the M-cones or the two in various combinations (both in-phase and in counterphase). In none of the stimuli, the S-cones were modulated. Additionally, standard and multifocal ERGs were measured. Analysis of the L- and M-cone pigment genes was performed by means of PCR, RFLP analysis and DNA sequencing techniques.RESULTS:
Macular dystrophy was revealed by the markedly abnormal multifocal ERGs in presence of near normal standard ERGs. The large field ERG responses were exclusively driven by the M-cones with enlarged thresholds when compared with otherwise normal protanopes. In addition, the M-cone driven ERG response phases were abnormal. Pigment gene analysis confirmed a protan genotype with the presence of a single 5'red/3'green hybrid pigment gene.CONCLUSIONS:
Our novel stimulus technique allows a reliable analysis of the separate cone pathways even in cases with macular dysfunction. The increased thresholds and the abnormal phase behavior of the M-cone driven ERGs reflect altered mechanisms of the retinal physiology in this patient. The data strongly suggest that the macular dystrophy and the protanopia have independent origins.
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Bases de datos:
MEDLINE
Asunto principal:
Pigmentos Retinianos
/
Defectos de la Visión Cromática
/
Células Fotorreceptoras Retinianas Conos
/
Electrorretinografía
/
Degeneración Macular
Límite:
Adult
/
Humans
/
Male
Idioma:
En
Revista:
Curr Eye Res
Año:
2001
Tipo del documento:
Article
País de afiliación:
Alemania