Song Hongxin, Rossi Ethan A, Williams David R
Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
BMJ Open Ophthalmol. 2021 Jan 8;6(1):e000603. doi: 10.1136/bmjophth-2020-000603. eCollection 2021.
Idiopathic macular telangiectasia (MacTel) is considered primarily a vascular disease affecting juxtafoveal retinal capillaries. However, recent evidence suggests that neuronal changes may occur early in disease development. We used high-resolution adaptive optics retinal imaging to elucidate the foveal cone photoreceptor changes at a cellular level in patients with MacTel.
We used adaptive optics scanning light ophthalmoscopy (AOSLO) to evaluate the foveal cone photoreceptors in the less-affected eye of patients with asymmetric MacTel. AOSLO images of cone photoreceptors were obtained in a 4°×4° area centred on the foveola. Individual cone positions were identified within a 2°×2° area centred on the fovea, using semiautomatic cone marking software with manual correction, permitting calculation of a map of cone density.
In all participants, one eye was affected with MacTel, the fellow eye was clinically normal or near normal, with visual acuity of 20/25 or better and subtle angiographic leakage. The foveal cone mosaics were continuous with tight packing and cones exhibited normal reflectivity. However, cone density was significantly lower for all participants (mean=80 733 cones/mm) within 0.5° than the cone density previously reported for normal eyes.
Foveal cone density is lower than normal in the clinically less-affected eyes of patients with asymmetric MacTel. This suggests that cone photoreceptor loss may precede classic obvious vascular changes in idiopathic MacTel.
特发性黄斑毛细血管扩张症（MacTel）主要被认为是一种影响黄斑旁视网膜毛细血管的血管疾病。然而，最近的证据表明，神经元变化可能在疾病发展早期就会出现。我们使用高分辨率自适应光学视网膜成像技术，在细胞水平上阐明MacTel患者的中央凹视锥光感受器变化。
我们使用自适应光学扫描激光检眼镜（AOSLO）评估不对称性MacTel患者患侧症状较轻眼睛的中央凹视锥光感受器。在以中央凹为中心的4°×4°区域内获取视锥光感受器的AOSLO图像。使用半自动视锥标记软件并进行手动校正，在以中央凹为中心的2°×2°区域内确定单个视锥的位置，从而计算视锥密度图。
所有参与者中，一只眼睛患有MacTel，另一只眼睛临床正常或接近正常，视力为20/25或更好，且血管造影有轻微渗漏。中央凹视锥镶嵌结构连续，排列紧密，视锥表现出正常的反射率。然而，所有参与者在0.5°范围内的视锥密度（平均=80733个视锥/mm）显著低于先前报道的正常眼睛的视锥密度。
在不对称性MacTel患者临床症状较轻的眼睛中，中央凹视锥密度低于正常水平。这表明在特发性MacTel中，视锥光感受器的丧失可能先于典型的明显血管变化。
