Epidemiologic study of rhegmatogenous retinal detachment in Japan from the Diagnosis Procedure Combination database over a 2-year period (2014-2015)

Purpose To determine the incidence of rhegmatogenous retinal detachments (RRDs) and proliferative vitreoretinopathies (PVRs) and their distribution by age and sex in hospitalized patients in Japan. Study design Retrospective nationwide observational study. Methods Information on the number of inpatients primarily diagnosed with RRD or PVR and their age and sex were collected from the Diagnosis Procedure Combination (DPC) database for 2014 and 2015. The incidence was determined using the Japanese population report published by the Public Management Ministry's Statistics Bureau. Results The incidence of RRD in these hospitalized patients was 10.9/100,000, with 15.0/100,000 in men and 7.1/100,000 in women, and that of PVR was 2.1/100,000, with 2.9/100,000 in men and 1.3/100,000 in women. The incidence in men was twice that in women for both RRD and PVR. The distribution of RRD by age was monophasic, with a peak at 50 years for both sexes, and that of PVR was at peak in the 60 s for men and in the 70 s for women. PVR was more common than RRD in children aged younger than 10 years, but the incidence of RRD was higher in the other age groups. Conclusion A study of the DPC database can provide useful information on the incidences of RRD and PVR in hospitalized patients in Japan.