Ueno Shinji, Nakanishi Ayami, Sayo Akira, Kominami Taro, Ito Yasuki, Hayashi Takaaki, Tsunoda Kazushige, Iwata Takeshi, Terasaki Hiroko
Department of Ophthalmology, Graduate School of Medicine, Nagoya University, 65 Tsuruma-cho, Showa-ku, Nagoya, 466-8550, Japan.
Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan.
Doc Ophthalmol. 2017 Apr;134(2):141-147. doi: 10.1007/s10633-017-9577-y. Epub 2017 Feb 14.
Patients with complete achromatopsia (ACHM) lack cone function, and patients with incomplete ACHM have relatively good visual acuity with residual color vision. The pathological mechanism(s) underlying incomplete ACHM has not been determined. The purpose of this study was to determine the pathophysiology of ACHM in two siblings: one with complete ACHM and the other with incomplete ACHM.
The medical charts of the two siblings were reviewed.
The sibling with incomplete ACHM had decimal visual acuities that ranged from 0.4 to 0.6 and had moderate color blindness in both eyes. Her younger brother was diagnosed with complete ACHM and was not able to hold fixation, had severe pendular nystagmus, visual acuity that ranged from 0.08 to 0.1, and severe color vision abnormalities in both eyes. Optical coherence tomography (OCT) showed that the ellipsoid zone (EZ) was disruptive in the macular region in both patients. However, careful examination of the OCT images in the incomplete ACHM patient showed a high-density EZ in the central fovea. Adaptive optics (AO) fundus imaging of the sibling with incomplete ACHM revealed sparse cone mosaics remaining within 1° of the foveal center with no mosaics visible outside the central fovea. AO fundus imaging could not be performed in Case 2 because of the severe nystagmus.
Our results showed that cone mosaics were present in the central fovea in the sibling with incomplete ACHM patient. This may explain the better visual acuity and color vision in this sibling.
完全性全色盲（ACHM）患者缺乏视锥细胞功能，而不完全性ACHM患者具有相对较好的视力及残余色觉。不完全性ACHM的病理机制尚未明确。本研究旨在确定两名同胞中ACHM的病理生理学特征，其中一名为完全性ACHM，另一名为不完全性ACHM。
回顾了这两名同胞的病历。
不完全性ACHM的同胞小数视力范围为0.4至0.6，双眼患有中度色盲。她的弟弟被诊断为完全性ACHM，无法固视，有严重的钟摆型眼球震颤，视力范围为0.08至0.1，双眼有严重的色觉异常。光学相干断层扫描（OCT）显示，两名患者黄斑区的椭圆体带（EZ）均遭到破坏。然而，仔细检查不完全性ACHM患者的OCT图像发现，中央凹有高密度的EZ。对不完全性ACHM的同胞进行自适应光学（AO）眼底成像显示，在中央凹中心1°范围内仍有稀疏的视锥细胞镶嵌，在中央凹以外未见镶嵌。由于严重的眼球震颤，无法对病例2进行AO眼底成像。
我们的结果显示，不完全性ACHM患者的同胞中央凹存在视锥细胞镶嵌。这可能解释了该同胞较好的视力和色觉。
