Table 1 Clinical characteristics of two affected sibs in the family

Onset (years)

Night blindness

5

9

Visual field defect

16

24

Decreased visual acuity

20

31

Ophthalmological examination

Visual acuity

RE CF/10

RE 20/60

LE CF/20

LE 20/80

Slit lamp

Mild cataract

Normal

Visual field

RE/LE: not detectable

RE/LE: nasal and temporal defects

Fundus

RE/LE: paravascular bone spicule pigmentation, RPE atrophy, pale disc, arteriolar constriction

RE/LE: paravascular bone spicule pigmentation, RPE atrophy, pale disc, arteriolar constriction

Optical coherence tomography

RE/LE: extensive ellipsoid band loss, RPE thinning

RE/LE: peripheral ellipsoid band loss, peripheral RPE thinning

Fundus autofluorescence

RE/LE: extensive hypo-fluorescence in the posterior pole

RE/LE: hyper-fluorescent ring in the macula

Electroretinogram

RE/LE: extinguished

RE/LE: extinguished