后囊膜混浊及其治疗对SD-OCT测量视网膜神经纤维层厚度的影响

Influence of posterior capsular opacity and its removal on retinal nerve fiber layer thickness measured with spectral domain optical coherence tomography

摘要:

目的：研究后囊膜混浊(posterior capsular opacity， PCO)及其治疗对使用谱域光学相干断层扫描(spectral domain optical coherence tomography， SD-OCT)测量视网膜神经纤维层(retinal nerve fiber layer， RNFL)厚度的影响。

方法：使用SD-OCT测量50例接受Nd： YAG激光后囊膜切开术患者术前和术后RNFL厚度。通过信噪比(signal to noise ratio， SNR)等级，将患者分为组1(SNR 3和4)、组2(SNR 5和6)及组3(SNR 7和8)。对侧眼作为对照组。

结果：接受了Nd： YAG激光后囊膜切开术的眼BCVA、SNR和RNFL均值显著增加。组1和组2激光治疗前后BCVA、SNR和RNFL均值显著不同。尽管组3中患者治疗前后BCVA和SNR均值显著不同，RNFL厚度在治疗前后没有显著差异。

结论：PCO对OCT图像质量有影响。所有接受后囊膜切开术的患者，术后SNR较术前有所改善。治疗前SNR7在以下的患者中，RNFL厚度在患者接受Nd： YAG激光后囊膜切开术后显著提高。

Abstract:

AIM:To investigate the influence of posterior capsular opacity(PCO)and its removal on retinal nerve fiber layer(RNFL)thickness measured with spectral domain optical coherence tomography(SD-OCT).

METHODS: Fifty patients underwent RNFL measurements using SD-OCT before and after Nd: YAG laser posterior capsulotomy. The patients were divided into groups according to the value of signal to noise ratio(SNR)measured by SD-OCT as group 1: SNR 3 and 4, group 2: SNR 5 and 6 and group 3: SNR 7 and 8. The other eye served as control(control group).

RESULTS: The mean BCVA, SNR and RNFL measurements significantly increased in eyes underwent Nd: YAG laser capsulotomy. The preoperative and postoperative mean BCVA, SNR and RNFL measurements were significantly different in group 1 and group 2. Although the preoperative and postoperative mean BCVA and SNR were significantly different, the preoperative and postoperative RNFL thickness weren't significantly different in group 3.

DISCUSSION: PCO has an influence on OCT image quality. SNR improved in all cases after removal of the PCO. However, RNFL thickness significantly improved after Nd:YAG laser capsulotomy in patients with preoperative SNR under 7.