Fundus Albipunctatus

This article describes this condition and demonstrates the use of electrophysiology including prolonged dark adaptation in its diagnosis

 

Definition: A member of Congenital Stationary Night Blindness Group

Inheritance: Autosomal Recessive

Clinical: Reduced night vision; Often Asymptomatic; Can adapt with prolonged time in reduced light. Often minmal symptoms. Non progressive; Normal Visual acuity and fields.

Signs: Numerous discrete white-yellow lesions. Evolve from flecks in childhood to discrete punctate permanent white retinal dots. Diagnosis confirmed by visual electrophysiology see  below

Differential Diagnosis: Includes retinitis punctata albescens; No evidence of inflammation as in other white dot conditions.

Genetic: Mutation RDH5 gene (Chromosome 12q13-14); note a rarely reported association with late onset Cone dysfunction at>40years.

fundus albipunctatus

 

Electrophysiology: ERGTo ISCEV standards- Rod Scotopic may be abolished; To Bright flash Reduced amplitudes of A and B may be Negative waveform. With prolonged dark adaptation (60-150minutes) normal scotopic response is obtained; Photopic ERG, pattern ERG and Multifocal ERG are normal expected to be normal but later in life may show an abnormality. EOG similarly improves with prolonged dark adaptation.The following slides demonstrate an initial negative ERG.

Subsequent slides show improving Rod ERG and Scotopic ERG with prolonged dark adaptation (80minutes). B/A wave ratio is also shown to improve.

Typical Visual Electrophysiology results: (Click arrows to view slides)

 

Treatment:None required.