Alvarez E, Wakakura M, Khan Z, Dutton G N
Tennent Institute of Ophthalmology, University of Glasgow, Scotland.
J Pediatr Ophthalmol Strabismus. 1988 May-Jun;25(3):151-4. doi: 10.3928/0191-3913-19880501-11.
The disc-macula: disc diameter (DM:DD) ratio is the ratio of the horizontal distance between the center of the optic disc and the macula to the mean diameter of the optic disc, as evaluated from fundus photographs. The diagnosis of optic nerve hypoplasia may be difficult in cases in which the optic discs are slightly reduced in size, or when the double ring sign is absent and the condition is bilateral. The DM:DD ratio was calculated for six eyes of five children with ophthalmoscopically obvious optic nerve hypoplasia, 12 eyes of six children in whom the diagnosis of optic nerve hypoplasia was equivocal (but established by visual field examination and retinal red free photography), 13 eyes of eight children with optic atrophy, and 25 eyes of 17 children with normal optic discs. The DM:DD ratio was found to be significantly higher for both groups with optic nerve hypoplasia than for those with optic atrophy and the normal controls. For practical purposes, when the DM:DD ratio is greater than 3.0, the diagnosis of optic nerve hypoplasia should be seriously considered.
视盘-黄斑：视盘直径（DM:DD）比值是指从眼底照片评估得出的视盘中心与黄斑之间的水平距离与视盘平均直径的比值。在视盘大小稍有减小的情况下，或者当双环征缺失且病情为双侧性时，视神经发育不全的诊断可能会很困难。计算了5名眼底镜检查显示明显视神经发育不全的儿童的6只眼、6名视神经发育不全诊断不明确（但通过视野检查和视网膜无赤光摄影确诊）的儿童的12只眼、8名视神经萎缩儿童的13只眼以及17名视盘正常儿童的25只眼的DM:DD比值。结果发现，两组视神经发育不全患者的DM:DD比值均显著高于视神经萎缩患者和正常对照组。实际应用中，当DM:DD比值大于3.0时，应认真考虑视神经发育不全的诊断。
