Abstract
Abstract: :
Purposes: Corneal foreign body (FB) has been studied in the aspects of health for workers. Many researchers have reported that FBs were localized in the lower half of cornea, and it has been considered that the localization may be caused by the existence of eyelids partially covering the upper half and that corneal trauma caused by FBs are to be generated in working. However, there exist quite a few FBs relating to non-working. In previous studies, only the number of FBs in the upper half was compared with that in the lower half, and their characteristics, such as entering routes, outbreaks, and so on, have been never scrutinized. In this study, characteristics of FBs were examined, and theoretical relationships between entering routes of FBs and the distribution were compared with real relationships, for purpose of clarifying characteristics of corneal trauma generated in non-working. Methods: Eyes used in this study was 78 and classified into two groups relative to working (WG) or non-working (NWG). The WG consisted of eyes with FBs entered from the front and NWG in uncertain directions. Figures with distribution of FBs on the whole and in each of WG and WGI using photographs of cornea and those with relationships between entering routes of FBs and the distribution using theory of probability were obtained and compared with each other. Results: Species of the FBs were mainly iron. The 80% of all the eyes belonged to WG and 20% to NWG. The lower half of cornea had more FBs than the upper half did on the whole and in each of WG and NWG. In NWG, all the FBs existed only in the lower half. There was a significant difference (Χ2 authorization p=.04) in distribution between WG and NWG. To remove iron rust brought with FBs, a drill was used as 2.5 times often as in WG than in NWG, and the degree of corneal trauma in WG was much severer than that in NWG. Conclusions: While localization of FBs in the lower half of cornea was observed as reported previously, characteristics of corneal trauma generated in non-working were clarified in this study. And no existence of FBs in the upper half of cornea and the light degree of corneal trauma were theoretically explained well. Further study needs for medical practices.
Keywords: 350 clinical (human) or epidemiologic studies: biostatistics/epidemiology methodology • 369 cornea: clinical science • 608 trauma