Unilateral pigmentary retinopathy in an Asian population

To report a series of Asian patients with unilateral pigmentary retinopathy.

Retrospective case series. Clinical features, fundus photography, fundus autofluorescence imaging (FAF), visual fields, optical coherence tomography (OCT) and electrophysiology were reviewed in 6 patients referred to two Singaporean inherited retinal disease clinics with suspected "unilateral retinitis pigmentosa".

Four patients presented with unilateral blurring of vision; 2 were asymptomatic. All index eyes and one fellow eye had FAF abnormalities consistent with visible fundus abnormalities. Visual fields were abnormal in all index and 2 fellow eyes. Macular OCT showed disruption of outer retinal layers in all index eyes and 1 fellow eye. Five index eyes had abnormal rod and cone full field electroretinogram (ERG) amplitudes, while one index eye had localized rod ERG amplitude abnormality. Two index eyes had 30 Hz flicker peak time delay. Three index eyes displayed cone greater than rod system involvement. Pattern electroretinography (PERG) demonstrated macular dysfunction in 5 index eyes and 2 fellow eyes. One case was diagnosed with possible RP. Alternative diagnoses (trauma and autoimmune retinopathy) were ascertained in 4 cases.

Electrophysiology was more sensitive than clinical examination and imaging in detecting retinopathy or maculopathy. In only 1 of 6 patients referred for possible unilateral RP was that diagnosis sustainable; four could be attributed to an identified acquired etiology. Although the diagnosis was unclear in the remaining case, the clinical findings and investigations were not compatible with an inherited disorder.