Abstract
Purpose :
In 2005, we began the Kyoto Glaucoma Screening Cohort (KGSC), designed to collect the data of hospital-based glaucoma-free subjects for our glaucoma genetic study for over 10 years. Since this cohort uses volunteer subjects not previously diagnosed as glaucoma, we can estimate the latent glaucoma prevalence without any symptoms over time, comparing those from the former and latter periods. In this study, we investigated the latent glaucoma prevalence over time in Japanese from our KGSC data, in comparison with that from the Tajimi study.
Methods :
During the study period, more than 2246 volunteers participated in KGSC, and of those, we selected 1899 subjects over 40 years of age for this observational study (642 males and 1257 females, mean age: 62.5+-9.3 years). All volunteers provided written informed consent after an explanation of the nature and possible consequences of the study, and were then examined by slit-lamp microscopy, non-mydriasis fundus photography (TRC-NW200; Topcon), frequency-doubling perimetry (FDT matrix; Carl Zeiss Meditec), and several other instruments. If subjects showed more than one scotoma in FDT, an additional test was performed. In cases where the FDT test failed in at least one eye, Humphrey automated perimetry with program 30-2 SITA Fast (Carl Zeiss Meditec) was performed. All cases were independently diagnosed by three glaucoma specialists. If the diagnosis was different by at least 1 doctor, the final diagnosis was made via group conference using all examination data. The diagnosis of glaucoma was based on the ISGEO glaucoma classification. The age-adjusted prevalence of glaucoma was then calculated from our data not only for the whole period, but also for the former and latter half periods based on the population model of the district of Kyoto in 2005.
Results :
For the former and latter half periods, the number of subjects was 1141 and 758, respectively. During the observation period, 83 normal-tension glaucoma cases, 1 primary open-angle glaucoma case, and 1 pseudoexfoliation glaucoma case was found. After adjustment for age, the latent glaucoma prevalence was 3.4, 3.2, and 3.5% for the whole, former, and latter period, respectively, and less than that reported in the Tajimi study.
Conclusions :
This study revealed that the latent glaucoma prevalence was less than that in the Tajimi study, with no change observed over a 5-year time period.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.