We report 4 cases of unilateral retinitis pigmentosa (URP) with a literature review.

A retrospective, observational case series of 4 URP patients with no signs of bilateral involvement during the follow-up period of up to 5 years.

The subjects were 4 female patients with an average age of 37 years. The mean follow-up period was 7 years. The subjects' blood analysis excluded any infective diseases. History of trauma or any family history of ocular diseases including retinitis pigmentosa was absent. The full-field electroretinograms (ERGs) were normal in the unaffected eyes and the affected eyes showed markedly low or undetectable responses. Computerized visual field examinations were normal in the unaffected eyes, while 3 of the affected eyes had total visual field loss and 1 had concentric narrowing within 20 degrees.

A long term follow-up of at least 5 years is required for diagnosis of URP to exclude a delayed onset in the unaffected eye. ERG is a reliable test to monitor the course of the disease and to confirm the diagnosis when uncertain. The etiology of URP is unknown although several studies regarding genetic causes that resulted in URP have been reported in recent years.