Lee N B
St George's Hospital, Tooting, London.
Br J Ophthalmol. 1990 May;74(5):294-6. doi: 10.1136/bjo.74.5.294.
This article describes the design of a +150 dioptre compound lens for biomicroscopic examination of the fundus. To compare the lens with other fundal examination techniques a method is described for measuring the magnification and vertical angle of view of the various examination lenses. By this method the +150 dioptre lens is shown to have an angle of view of 60 degrees. This is similar to that of the indirect ophthalmoscope when used with a 20 dioptre lens which has an angle of view of 57 degrees. However, the magnification of the +150 dioptre lens is greater at X5.2 compared with X3.0 for the indirect ophthalmoscope. The practical applications of the lens are discussed. In comparison the field of view of the +78 and +90 dioptre lenses are 37 degrees and 29 degrees respectively. The +150 dioptre lens has proved a useful adjunct enabling a rapid global screening of the ocular fundus on the slit-lamp before examining any particular area of interest in more detail.
本文介绍了一种用于眼底生物显微镜检查的+150屈光度复合透镜的设计。为了将该透镜与其他眼底检查技术进行比较，描述了一种测量各种检查透镜放大倍数和垂直视角的方法。通过这种方法，+150屈光度透镜的视角为60度。这与使用20屈光度透镜的间接检眼镜的视角（57度）相似。然而，+150屈光度透镜的放大倍数为X5.2，大于间接检眼镜的X3.0。文中讨论了该透镜的实际应用。相比之下，+78和+90屈光度透镜的视野分别为37度和29度。+150屈光度透镜已被证明是一种有用的辅助工具，能够在裂隙灯上对眼底进行快速全面筛查，然后再更详细地检查任何特定感兴趣区域。
