- 期刊
- OpenAccess
關於角膜前面彎曲度（附中國人正常兒童之角膜前面彎曲度測定成績）
The Corneal Curvature (Anterior Surface) with Results of Measuring 918 Normal Chinese Children Eyes
並列摘要
The Corneal Curvature (Anterior Surface) with Results of Measuring 918 Normal Chinese Children Eyes The corneal curvature is an important factor in the refractive system of the eye. It was reported by many authors that the corneal curvature would be different according to race, age, sex and height etc. This paper was presented in order to determine the corneal curvature of chinese normal eyes and discuss some problems concerning the factors which would effect on the corneal curvature. Some discussion about corneal astigmatism were also made in this paper. The 1238 eyes of pupils in Tung-Meng Primary school in Taipei were examined and 918 eyes (within ±0.5 D) were selected. Except the corneal curvature, the refraction both hefore and after cycloplegica, corneal size, exophthalmos, size of lid fissure and pupillary distance were all measured. The method of measuring the corneal curvature was discussed in detail and several factors to effect on the results in the examination period were avoided as far as possible. Thus, using the Zeiss (Opton) Ophthalmometer, the corneal curvature was measured twice both vertically and horizontally. Then the average result of the vertical and horizontal corneal curvature was taken as the corneal curvature of the eye. The results obtained were as follows: 1) The corneal curvature of the chinese children eyes was 7.635 mm. in radius in average of 918 eyes. This (radius) is larger than that of the Japanese and smaller than that of the Europeans and Americans. 2) The corneal curvature of male students was larger in radius (R=7.689mm) than that of female students (R=7.583mm). This difference is statistically significant. 3) The corneal curvature inclined to increase in radius acording to age but its inclination was not so evident as reported previouslly by many authors. 4) The corneal curvature of Taiwanese students was larger in radius than that of mainland students. But this is statistically not significant. 5) A majority of isometropes had the difference of the corneal curvature between two eyes. The largest difference reached to 0.2 mm. in radius 6) 95.05% of the eyes which showed no astigmatism clinically was proved to have corneal astigmatism. The highest power of the corneal astigmatism reached to 2.5 D (0.49 mm). These corneal astigmatism might be neutralized by the lens astigmatism and other factors (which was what so called residual astigmatism.) 7) Inverse astigmatism (astigmatism against rule) was very rare in childhood. 8) The crossing angle of both axises of corneal astigmtism was not absolutely at right angle (90°) in the most cases, but within 90°±10°.