| Budget Amount *help |
¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 2003: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2002: ¥1,900,000 (Direct Cost: ¥1,900,000)
|
|---|
| Research Abstract |
The prevalence of hearing loss, progressive hearing loss, tinnitus and dizziness, and age at onset of hearing loss were evaluated by questionnaire in subjects who were registered members of the Japanese Retinitis Pigmen tosa Society (n=3200) in the year 2002. 834 questionnaires were returned (26.1% response rate), but only 828 subjects (25.9%) who had been diagnosed with Retinitis Pigmentosa (RP) by an ophthalmologist were included in the analysis. The prevalence of cochlear symptoms (hearing loss: 29.5%, tinnitus 30.4%) was 43.0% (n=356). Of 356 subjects with cochlear symptoms, progressive hearing loss and dizziness were 44.9% and 56.5%, respectively. The mean ages at onset of hearing loss and visual loss were 39.2 years old and 31.7 years old, respectively. There was no significant difference in progressive hearing loss among subjects with different ages of hearing loss on set. 63.5% of the subjects with cochlear symptoms had a history of audiometric examination, and 22.1% of the subjects with hearing loss (n=244) used a hearing aid. Overall, the rate of occurrence of cochlear symptoms was calculated to be 7.0 per 100,000 in the general population (where subjects with an age at onset of cochlear symptom of 61 or older were excluded from the calculation). There is a difference in prevalence rate of cochlear symptonis with RP according to place of residence. In Hokkaido (in the most northerly part of Japan) the rate is lowes t (4.7/100,000), whereas it is highest in Kyushu (8.5/100,000). In order to achieve accurate diagnosis of this disease, studies must be performed to correlate clinical phenotypes with genotypes for the majority of patients.
|
