Departments of *Biomedical Engineering †Electrical & Computer Engineering, The University of Texas at Austin, Austin, TX ‡Imaging Physics, MD Anderson Cancer Center, The University of Texas, Houston, TX §Departments of Ophthalmology and Neurobiology, Duke University Medical Center, Durham, NC.
J Glaucoma. 2014 Jan;23(1):e45-52. doi: 10.1097/IJG.0b013e31829ea2a7.
Compare performance of normalized reflectance index (NRI) and retinal nerve fiber layer thickness (RNFLT) parameters determined from optical coherence tomography (OCT) images for glaucoma and glaucoma suspect diagnosis.
Seventy-five eyes from 71 human subjects were studied: 33 controls, 24 glaucomatous, and 18 glaucoma-suspects. RNFLT and NRI maps were measured using 2 custom-built OCT systems and the commercial instrument RTVue. Using area under the receiver operating characteristic curve, RNFLT and NRI measured in 7 RNFL locations were analyzed to distinguish between control, glaucomatous, and glaucoma-suspect eyes.
The mean NRI of the control group was significantly larger than the means of glaucomatous and glaucoma-suspect groups in most RNFL locations for all 3 OCT systems (P<0.05 for all comparisons). NRI performs significantly better than RNFLT at distinguishing between glaucoma-suspect and control eyes using RTVue OCT (P=0.008). The performances of NRI and RNFLT for classifying glaucoma-suspect versus control eyes were statistically indistinguishable for PS-OCT-EIA (P=0.101) and PS-OCT-DEC (P=0.227). The performances of NRI and RNFLT for classifying glaucomatous versus control eyes were statistically indistinguishable (PS-OCT-EIA: P=0.379; PS-OCT-DEC: P=0.338; RTVue OCT: P=0.877).
NRI is a promising measure for distinguishing between glaucoma-suspect and control eyes and may indicate disease in the preperimetric stage. Results of this pilot clinical study warrant a larger study to confirm the diagnostic power of NRI for diagnosing preperimetric glaucoma.
比较光学相干断层扫描（OCT）图像中标准化反射指数（NRI）和视网膜神经纤维层厚度（RNFLT）参数在青光眼和疑似青光眼诊断中的性能。
研究了 71 名人类受试者的 75 只眼睛：33 名对照者、24 名青光眼患者和 18 名疑似青光眼患者。使用 2 种定制的 OCT 系统和商用仪器 RTVue 测量了 RNFLT 和 NRI 图。使用受试者工作特征曲线下面积，分析了 7 个 RNFL 位置的 RNFLT 和 NRI，以区分对照组、青光眼组和疑似青光眼组的眼睛。
在所有 3 种 OCT 系统中，大多数 RNFL 位置的对照组的平均 NRI 明显大于青光眼组和疑似青光眼组的平均值（所有比较 P<0.05）。与 RTVue OCT 相比，NRI 在区分疑似青光眼和对照组方面的表现明显优于 RNFLT（P=0.008）。对于 PS-OCT-EIA（P=0.101）和 PS-OCT-DEC（P=0.227），NRI 和 RNFLT 用于区分疑似青光眼与对照组的性能在统计学上无显著差异。对于 PS-OCT-EIA（P=0.379）、PS-OCT-DEC（P=0.338）和 RTVue OCT（P=0.877），NRI 和 RNFLT 用于区分青光眼与对照组的性能在统计学上无显著差异。
NRI 是区分疑似青光眼和对照组的有前途的指标，可能表明在视野前期有疾病。这项初步临床研究的结果需要更大的研究来证实 NRI 诊断前期青光眼的诊断能力。
