Sumaroka Alexander, Matsui Rodrigo, Cideciyan Artur V, McGuigan David B, Sheplock Rebecca, Schwartz Sharon B, Jacobson Samuel G
Invest Ophthalmol Vis Sci. 2016 Jul 1;57(9):OCT253-61. doi: 10.1167/iovs.15-18860.
To study transition zones from normal to abnormal retina in Usher syndrome IB (USH1B) caused by myosin 7A (MYO7A) mutations.
Optical coherence tomography (OCT) scattering layers in outer retina were segmented in patients (n = 16, ages 2-42; eight patients had serial data, average interval 4.5 years) to quantify outer nuclear layer (ONL) and outer segments (OS) as well as the locus of EZ (ellipsoid zone) edge and its extent from the fovea. Static perimetry was measured under dark-adapted (DA) and light-adapted (LA) conditions.
Ellipsoid zone edge in USH1B-MYO7A could be located up to 23° from the fovea. Ellipsoid zone extent constricted at a rate of 0.51°/year with slower rates at smaller eccentricities. A well-defined EZ line could be associated with normal or abnormal ONL and/or OS thickness; detectable ONL extended well beyond EZ edge. At the EZ edge, the local slope of LA sensitivity loss was 2.6 (±1.7) dB/deg for central transition zones. At greater eccentricities, the local slope of cone sensitivity loss was shallower (1.1 ± 0.4 dB/deg for LA) than that of rod sensitivity loss (2.8 ± 1.2 dB/deg for DA).
In USH1B-MYO7A, constriction rate of EZ extent depends on the initial eccentricity of the transition. Ellipsoid zone edges in the macula correspond to large local changes in cone vision, but extramacular EZ edges show more pronounced losses on rod-based vision tests. It is advisable to use not only the EZ line but also other structural and functional parameters for estimating natural history of disease and possible therapeutic effects in future clinical trials of USH1B-MYO7A.
研究由肌球蛋白7A（MYO7A）突变引起的Usher综合征IB型（USH1B）中从正常视网膜到异常视网膜的过渡区域。
对患者（n = 16，年龄2 - 42岁；8例患者有连续数据，平均间隔4.5年）的视网膜外层光学相干断层扫描（OCT）散射层进行分割，以量化外核层（ONL）和外节（OS），以及椭圆体带（EZ）边缘的位置及其距中央凹的范围。在暗适应（DA）和明适应（LA）条件下进行静态视野检查。
USH1B - MYO7A中的椭圆体带边缘可位于距中央凹达23°处。椭圆体带范围以每年0.51°的速度收缩，在较小偏心度时收缩速度较慢。明确的EZ线可能与正常或异常的ONL和/或OS厚度相关；可检测到的ONL延伸到EZ边缘之外。在EZ边缘，中央过渡区域明适应敏感度损失的局部斜率为2.6（±1.7）dB/度。在更大偏心度时，视锥细胞敏感度损失的局部斜率（明适应时为1.1±0.4 dB/度）比视杆细胞敏感度损失的局部斜率（暗适应时为2.8±1.2 dB/度）更平缓。
在USH1B - MYO7A中，EZ范围的收缩率取决于过渡的初始偏心度。黄斑区的椭圆体带边缘对应视锥细胞视觉的大幅局部变化，但黄斑外的EZ边缘在基于视杆细胞的视觉测试中显示出更明显的损失。在未来USH1B - MYO7A的临床试验中，不仅使用EZ线，还使用其他结构和功能参数来估计疾病的自然史和可能的治疗效果是可取的。
