Abstract
Purpose: :
To determine the frequency of optic disc hemorrhages in the Chinese population.
Methods: :
The population–based prevalence survey included 4439 subjects out of 5324 subjects invited to participate (response rate 83.4%) with an age of 40+ years. It was divided into a rural part (1973 (44.4%) subjects) and an urban part (2466 (55.6%) subjects). Mean age was 56.2 ± 10.6 years (range, 40 – 101 years). Color optic disc photographs (45°) were morphometrically examined. Optic disc hemorrhages were defined as bleedings inside of the optic disc or touching the disc border, without a detected retinal cause for the bleeding. .
Results: :
Optic disc photographs were available for 8655 eyes of 4378 subjects (98.6%) subjects. Prevalence of optic disc hemorrhages was 1.21 ± 10.94% (95% confidence interval (CI): 0.89%, 1.53%) per eye. In binary logistic regression analysis, occurrence of optic disc hemorrhage remained to be significantly associated with glaucomatous optic nerve damage (p<0.001) and age (p=0.017). It was not significantly associated with rural versus urban region (p=0.12), intraocular pressure (p=0.69), refractive error (p=0.12), and score of visual field defects (p=0.19). Defining glaucoma as glaucomatous appearance of the optic disc, 20 (18.7%) of the disc hemorrhage were found in glaucomatous eyes. Out of 226 glaucomatous eyes, 20 (8.8%) showed a disc hemorrhage.
Conclusions: :
Major associated factors for optic disc hemorrhages are glaucomatous optic neuropathy and age. Optic disc hemorrhages occur in a frequency of about 1.2% in eyes of adult Chinese. If present, they may point with a probability of about 20% towards glaucomatous optic nerve damage. About 9% of glaucomatous eyes show a disc hemorrhage at the time of examination.
Keywords: optic disc • clinical (human) or epidemiologic studies: biostatistics/epidemiology methodology • nerve fiber layer