van Velthoven M E J, van der Linden M H, de Smet M D, Faber D J, Verbraak F D
Department of Ophthalmology, Academic Medical Centre, Meibergdreef 9, Amsterdam, The Netherlands.
Br J Ophthalmol. 2006 Oct;90(10):1259-62. doi: 10.1136/bjo.2004.097022.
As optical coherence tomography (OCT) is widely used for diagnosis and monitoring of ocular pathology, especially in the elderly people, the influence of cataract on image quality and macular retinal thickness was studied.
In 29 patients scheduled for cataract surgery, preoperative and postoperative OCT scans were obtained. Cataracts were categorised as nuclear, posterior or cortical. Parameters for image quality (signal-to-noise ratio (SNR)) and signal strength and macular thickness were compared. A three-level expert grading scale was used to evaluate the discriminative abilities of SNR and signal strength.
Nuclear cataracts (n = 12) provided better preoperative scans (higher SNR/signal strength) than posterior (n = 7) and cortical (n = 10) cataracts (p<0.004). Postoperatively SNR and signal strength increased significantly in all patients (p<0.001). The SNR was better at discriminating poor from acceptable and good scans than signal strength (area under the receiver operating curve: 0.879 and 0.810, respectively). Postoperative macular thickness overall showed a significant increase (p = 0.005), most evident in patients with posterior cataracts (p = 0.028).
OCT imaging is influenced by cataract; image quality is reduced preoperatively and macular thickness measurements are slightly increased postoperatively. In individual patients, OCT scans remain reliable for gross clinical interpretation, even in the presence of cataract.
由于光学相干断层扫描（OCT）广泛用于眼部疾病的诊断和监测，尤其是在老年人中，因此研究了白内障对图像质量和黄斑视网膜厚度的影响。
对29例计划进行白内障手术的患者进行术前和术后的OCT扫描。白内障分为核性、后囊下或皮质性。比较图像质量参数（信噪比（SNR））、信号强度和黄斑厚度。采用三级专家评分量表评估SNR和信号强度的鉴别能力。
核性白内障（n = 12）术前扫描效果（SNR/信号强度更高）优于后囊下白内障（n = 7）和皮质性白内障（n = 10）（p<0.004）。所有患者术后SNR和信号强度均显著增加（p<0.001）。SNR在区分差的扫描与可接受和良好的扫描方面比信号强度更好（受试者操作特征曲线下面积分别为0.879和0.810）。术后黄斑厚度总体显著增加（p = 0.005），在后囊下白内障患者中最为明显（p = 0.028）。
OCT成像受白内障影响；术前图像质量降低，术后黄斑厚度测量值略有增加。对于个体患者，即使存在白内障，OCT扫描对于总体临床解读仍然可靠。
