National Hospital for Neurology and Neurosurgery, London, United Kingdom.
J Neuroophthalmol. 2013 Sep;33(3):256-9. doi: 10.1097/WNO.0b013e31829b4240.
Previous reports of epidemics of optic neuropathy in Africa have mainly focused on eastern and central areas. Our study aimed to measure the prevalence of optic neuropathy in The Gambia, a West African country, and compare this prevalence with a simultaneously occurring epidemic of optic neuropathy, now considered endemic, in Tanzania.
The sample population, derived from the Gambian National Blindness Survey (1996), was selected using simple random sampling. Thirty-three cases of low vision/blindness were identified where optic neuropathy was the sole cause of visual loss. Within a month, 31 cases were located and these patients underwent ophthalmic and peripheral nerve assessment and completed lifestyle questionnaires.
Five of the 31 individuals were found to have bilateral symmetrical optic neuropathy. Although it was not possible to fully ascertain etiology, the phenotype is compatible with epidemic, presumed nutritional, optic neuropathy described in Tanzania. Comparative prevalence data suggest a prevalence of 0.07% in The Gambia based on a total sample size of 6873 vs 2.4% in Tanzania.
Our data indicate that bilateral optic neuropathy is nonepidemic in The Gambia. Rare vitamin B12 and folate deficiencies reported in rural Gambians may explain the low prevalence because previous epidemics were due to nutrient deficiency. Our study is the only available estimate of epidemic optic neuropathy in The Gambia and, as such, provides an important contribution to our knowledge in identifying characteristics that may cause specific populations to be more susceptible to this public health burden.
以前关于非洲视神经病变流行的报告主要集中在东部和中部地区。我们的研究旨在测量冈比亚（一个西非国家）视神经病变的流行率，并将其与坦桑尼亚目前被认为是地方性的同时发生的视神经病变流行进行比较。
采用简单随机抽样法从冈比亚全国盲症调查（1996 年）中抽取样本人群。确定了 33 例低视力/失明病例，其中视神经病变是视力丧失的唯一原因。在一个月内，找到了 31 例患者，对这些患者进行了眼科和周围神经评估，并完成了生活方式问卷。
在 31 名个体中，有 5 名患有双侧对称性视神经病变。尽管无法完全确定病因，但表型与在坦桑尼亚描述的流行、推测的营养性视神经病变相符。比较患病率数据表明，根据 6873 人的总样本量，冈比亚的患病率为 0.07%，而坦桑尼亚的患病率为 2.4%。
我们的数据表明，双侧视神经病变在冈比亚并非流行。在农村冈比亚人中报告的罕见维生素 B12 和叶酸缺乏可能解释了低患病率，因为以前的流行是由于营养缺乏引起的。我们的研究是冈比亚唯一可用的流行视神经病变估计值，因此为我们识别可能使特定人群更容易受到这种公共卫生负担影响的特征提供了重要贡献。
