Division of Pediatric Hematology and Oncology, Rainbow Babies and Children’s Hospital and Department of Pediatrics, Case Western Reserve University, Cleveland, OH, USA.
Neuro Oncol. 2013 Aug;15(8):1088-95. doi: 10.1093/neuonc/not068. Epub 2013 May 7.
No more than half of patients with neurofibromatosis type 1 (NF1)-associated optic pathway gliomas (OPGs) develop vision loss. Prospectively identifying those who will require therapy remains challenging, because no reliable factors have yet been identified that predict future vision loss. To determine whether brain tissue microstructure is associated with visual acuity loss, we examined diffusion tensor imaging (DTI) and ophthalmologic evaluations in children with NF1-associated OPG.
We retrospectively reviewed ophthalmology records and concurrent DTI measurements of the optic nerves, tracts, and radiations from 50 children with NF1-associated OPGs. Multivariate linear regression measured the association between fiber trajectory quantity and white matter integrity on visual acuity measured by the logarithm of the minimal angle of resolution (logMAR).
In multivariate analysis, fractional anisotropy (FA) of the optic radiations was associated with visual acuity loss (adjusted coefficient = -6.081 logMAR/FA; P = .006) after adjusting for age, extent of tumor, DTI acquisition type, prior chemotherapy, and fundus examination findings. The association remained after eliminating tumors involving the optic radiations. In an evaluation of 15 subjects with paired ophthalmologic examination and DTI a year apart, initial FA of the optic radiation was associated with a trend toward change in visual acuity a year later (coefficient = -2.652 logMAR/FA; P = .069).
A decrease in FA of the optic radiations is associated with abnormal visual acuity in NF1-associated OPGs and may be predictive of visual acuity loss during the following year.
仅有半数左右的神经纤维瘤病 1 型（NF1）相关视神经胶质瘤（OPG）患者会出现视力丧失。目前仍难以前瞻性地识别出那些需要治疗的患者，因为尚未发现可靠的因素可以预测未来的视力丧失。为了确定脑组织微观结构是否与视力丧失有关，我们检查了 NF1 相关 OPG 患儿的弥散张量成像（DTI）和眼科评估结果。
我们回顾性地研究了 50 名 NF1 相关 OPG 患儿的眼科记录和同时进行的视神经、束和放射状视神经的 DTI 测量。多元线性回归测量了纤维轨迹数量与视神经最小分辨角对数（logMAR）视力测量的白质完整性之间的关联。
在多元分析中，视神经放射状纤维的各向异性分数（FA）与视力丧失相关（调整后的系数=-6.081 logMAR/FA；P=0.006），校正了年龄、肿瘤范围、DTI 采集类型、先前的化疗和眼底检查结果。在排除了涉及视神经放射状纤维的肿瘤后，该关联仍然存在。在对 15 名患儿进行眼科检查和 DTI 检查的随访研究中，视神经放射状纤维的初始 FA 与一年后视力变化呈趋势相关（系数=-2.652 logMAR/FA；P=0.069）。
视神经放射状纤维的 FA 值降低与 NF1 相关 OPG 中的异常视力相关，并且可能预测下一年的视力丧失。
