Epidemiologic characteristics of rhegmatogenous retinal detachment in Kumamoto, Japan

• Background: The epidemiology of rhegmatogenous retinal detachment in Asians is not well known. We studied the epidemiologic characteristics of rhegmatogenous retinal detachment in Kumamoto, Japan. • Methods: The study was based on a retrospective chart review of hospital patients who were treated for primary rhegmatogenous retinal detachment in 1990. The data were collected from seven hospitals in the Kumamoto area. • Results: From a population of 1 840000, 192 residents developed retinal detachment. The annual incidence was therefore 10.4 per 100000 population (9.6 for males, 11.2 for females). The incidences of three types of detachment — nontraumatic phakic, aphakic, and blunt trauma — were 9.8, 0.5, and 0.2 per 100000 population, respectively. In 109 of 180 patients (60.6%) with nontraumatic phakic detachment, retinal breaks were associated with lattice degeneration. In females, 14 of 106 nontraumatic phakic cases (13.2%) were secondary to macular holes. • Conclusion: Compared with previously published studies from other countries, the incidence of detachments associated with lattice degeneration and macular hole was higher, while the incidences of aphakic detachment and detachment due to blunt trauma were lower in Japan. Racial factors and living habits may affect the development of retinal detachment.