Sir,

Atrophy involving the choroid and retina is a consequence of infective, inflammatory, or degenerative processes and classified according to observed patterns and geographic location.1 Formulating a congenital, hereditary, or acquired pathological cause and diagnosis can be challenging in patients with a late presentation. We report a distinctive case of symmetrical, chorioretinal atrophy not previously described.

Case report

A 67-year-old woman presented with a 14-year history of abnormal colour vision and decreased vision over the last 5 years in bright sunlight and dim light. There was no significant past medical history other than hypertension, which was well controlled with oral ramipril. Family history included paternal blindness of unknown cause at the same age and a 35-year-old daughter who had noticed mild nyctalopia over the past 3 years.

On examination, the visual acuity was 6/6 OD 6/9 OS. Colour vision was absent in each eye. No abnormality was noted in the anterior segments and bilateral, mild nucleosclerotic cataracts were present. The vitreous was clear bilaterally with no evidence of previous inflammation. The striking abnormality was widespread mid peripheral areas of RPE atrophy in a scalloped, lobular pattern (Figure 1). Temporally there were areas of bone spicule-like pigmentation. Centrally there was a preserved area of RPE at each fovea. Both optic nerves appeared unremarkable with healthy neuroretinal rims. Goldmann visual fields showed relatively well preserved visual fields with paracentral ring scotomas and also a temporal scotoma in the right eye (Figure 2). Electrophysiology was unrecordable. Serum ornithine levels were within normal range. The fundal appearances and visual fields have remained unchanged since the patient was first seen in 2003 (Figure 3).

Figure 1
figure 1

Fundoscopic photographs of right and left eyes.

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Figure 2
figure 2

Right Goldmann Visual Field.

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Figure 3
figure 3

Left Goldmann Visual Field.

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Comment

This unusual retinal dystrophy could represent a rare, autosomal dominant phenotype. The positive, but uninvestigated, family history and the observed phenotype makes the differential diagnoses of congenital abnormality related to choroidal inflammation, retinotoxic medication uses, infective, inflammatory, systemic metabolic or choroidal vasculopathy highly improbable.

Other causes of well-defined atrophy such as this occurs in choroideremia, gyrate atrophy, and bifocal choroidal atrophy. However, none of these are consistent with this case. In summary, we present a novel lobular chorioretinal dystrophy for discussion.