Purpose

To determine the utility of ophthalmology evaluation, dark-adapted threshold, and full-field electroretinogram for early detection of Usher syndrome in young patients with bilateral sensorineural hearing loss.

Methods

We identified 39 patients with secure genetic diagnoses of Usher Syndrome. Visual acuity, spherical equivalent, fundus appearance, dark-adapted threshold, and full-field electroretinogram results were summarized and compared to those in a group of healthy controls with normal hearing. In those Usher patients with repeated measures, regression analysis was done to evaluate for change in visual acuity and dark-adapted threshold with age. Spherical equivalent and full-field electroretinogram responses from dark- and light-adapted eyes were evaluated as a function of age.

Results

The majority of initial visual acuity and spherical equivalent results were within normal limits for age. Visual acuity and dark-adapted threshold worsened significantly with age in Usher type 1 but not in Usher type 2. At initial test, full-field electroretinogram responses from dark- and light-adapted eyes were abnormal in 53% of patients. Remarkably, nearly half of our patients (17% of Usher type 1 and 30% of Usher type 2) would have been missed by tests of retinal function alone if evaluated before age 10.

Conclusions

Although there is an association of abnormal dark-adapted threshold and full-field electroretinogram at young ages in Usher patients, it appears that a small but important proportion of patients would not be detected by tests of retinal function alone. Thus, genetic testing is needed to secure a diagnosis of Usher syndrome.

中文翻译：

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暗适应阈值和视网膜电图诊断 Usher 综合征

目的

确定眼科评估、暗适应阈值和全视野视网膜电图在双侧感音神经性听力损失年轻患者早期检测 Usher 综合征中的效用。

方法

我们确定了 39 名安全基因诊断为 Usher 综合征的患者。总结视力、等效球镜、眼底外观、暗适应阈值和全视野视网膜电图结果，并与一组听力正常的健康对照组进行比较。在那些反复测量的 Usher 患者中，进行回归分析以评估视力和暗适应阈值随年龄的变化。对适应暗和适应光的眼睛的球面等效和全视野视网膜电图响应作为年龄的函数进行了评估。

结果

大多数初始视力和等效球面结果都在年龄的正常范围内。在 Usher 1 型中，视力和暗适应阈值随着年龄的增长而显着恶化，但在 Usher 2 型中则没有。在初始测试中，53% 的患者的暗适应和光适应眼睛的全视野视网膜电图反应异常。值得注意的是，如果在 10 岁之前进行评估，我们将近一半的患者（17% 的 Usher 1 型和 30% 的 Usher 2 型）仅通过视网膜功能测试就会被遗漏。

结论

尽管 Usher 患者在年轻时暗适应阈值异常和全视野视网膜电图存在关联，但仅通过视网膜功能测试似乎无法检测到一小部分但重要的患者。因此，需要基因检测来确保对 Usher 综合征的诊断。