Evaluation of Retinal Nerve Fiber Layer in Patients with Idiopathic Optic Perineuritis using Optical Coherence Tomography

The aim of this study was to assess the effect of idiopathic Optic perineuritis on the retinal nerve fiber layer, and determine the ability of optical coherence tomography to evaluate retinal nerve fiber loss after idiopathic Optic perineuritis. Four patients were assessed in this study. In all cases, average retinal nerve fiber layer was significantly thinner in the affected eye in comparison with the normal reference value and with the value for the contralateral normal eye at 12 months after the onset of optic perineuritis. Our study revealed that retinal nerve fiber layer loss occurs in idiopathic optic nerve sheath inflammation.     

HD-OCT测量黄斑区神经节细胞层-内丛状层厚度对开角型青光眼诊断的意义

目的：评估利用高分辨率相干光断层扫描( Cirrus-HD OCT)测量黄斑区神经节细胞层-内丛状层( GCIPL)厚度参数对早期和中晚期青光眼的诊断意义。
　　方法：本研究共纳入20例健康个体,26例早期青光眼患者,29例中晚期青光眼患者。对所有纳入个体均测量黄斑区GCIPL厚度参数,视盘( ONH )区参数以及视盘周围神经纤维层( RNFL )厚度参数。最后将所有数据利用SPSS 17.0统计学软件进行分析,分别计算各参数诊断早期和中晚期青光眼的AUC值,以比较和评价各参数的诊断意义。
　　结果：对于早期青光眼组, AUC值最高的为RNFL平均值(0.871)和7：00位值(0.896),GCIPL各参数也表现出较高的AUC值,其中GCIPL平均值和最小值相应的AUC值分别为0.847和0.812。对于中晚期青光眼组,AUC值最高为盘沿面积(0.992),其次为RNFL平均值(0.991),而GCIPL各参数中平均值与最小值的AUC值分别为0.967和0.983。对于早期青光眼诊断,灵敏度最高的指标为RNFL平均值(76.9%),而特异度最高的指标为GCIPL平均值(93.5%)。
　　结论：GCIPL作为诊断青光眼的新指标在诊断早期和中晚期青光眼时,具有与RNFL相似的诊断意义。对于早期青光眼,诊断时应重点观察RNFL平均值,而在筛查时应重点观察GCIPL的平均值。     

SMILE手术设计不同厚度角膜帽的临床对比观察

目的：比较不同厚度角膜帽设计对飞秒激光微小切口基质透镜切除术(small incision lenticule extraction,SMILE)手术的影响。

方法：收集我院拟行SMILE手术的近视患者46例92眼,随机平均分为两组,A组角膜帽厚度设计为110μm,B组角膜帽厚度设计为120μm,其余手术参数设计一致,手术均由同一手术医生完成。对比两组患者术中发生不透明气泡层(opaque bubble layer,OBL)情况、透镜分离困难比率,以及术后各时间段的裸眼视力(uncorrected visual acuity,UCVA)和等效球镜度数(spherical equivalent,SE)。

结果：术中OBL发生比例两组差异有统计学意义(P<0.05)：110μm组高于120μm组; 透镜分离困难比率两组差异有统计学意义(P<0.05)：110μm组高于120μm组。术后1d和7d时120μm组UCVA较110μm组好,但随着时间的推移,术后1,3,6mo时两组UCVA相近,两组数据比较无统计学差异(P>0.05); 且两组SE在术后7d和6mo时比较,差异无统计学意义(P>0.05)。

结论：110μm角膜帽设计较120μm设计的SMILE手术更容易出现OBL以及透镜分离困难,从而影响术后裸眼视力恢复的速度,远期裸眼视力无明显差异。     

应用3D OCT测量中老年人正常眼视网膜神经纤维层厚度

目的：建立我国40～69岁中老年人正常眼视网膜神经纤维层(retinal nerve fiber layer,RNFL)厚度的参考值范围,为青光眼的早期诊断提供参考依据。

方法：用Topcon 3D OCT-2 000(Ver 8.0)对40～69岁中老年人90例180眼以视乳头为中心、直径为3.4mm的环形线的RNFL厚度进行测量,并记录各个钟点位、各象限、平均RNFL厚度。对数据进行统计学分析,分析正常眼RNFL厚度与年龄、性别、眼别的关系,得出中老年人正常眼RNFL厚度特点及参考值。

结果：40～69岁中老年人正常眼RNFL厚度曲线分布呈双峰型,下方>上方>鼻侧>颞侧; 10：00位、5：00位、6：00位、上方RNFL厚度随年龄增长而变薄,10：00位差异有统计学意义(P<0.05),其余均无统计学差异(P>0.05); 除11：00位外,其余RNFL厚度与性别无关; 11：00位、12：00位、1：00位、4：00位、上方及鼻侧RNFL厚度与眼别有关,差异有统计学意义(P<0.05)。

结论：Topcon 3D OCT-2 000可以有效测量40～69岁中老年人RNFL厚度,为青光眼的早期诊断提供依据。     

Macular thickness measurements using Copernicus Spectral Domain Optical Coherence Tomography

Purpose

To provide normal macular thickness measurements using Spectral Domain Optical Coherence Tomography (SDOCT, Copernicus, Optopol Technologies, Zawierci, Poland).

Methods

Fifty-eight eyes of 58 healthy subjects were included in this prospective study. All subjects had comprehensive ophthalmic examination including best-corrected visual acuity (BCVA). All the subjects underwent Copernicus SDOCT. Central foveal thickness (CFT) and photoreceptor layer (PRL) thickness were measured and expressed as mean and standard deviation. Mean retinal thickness for each of the 9 regions defined in the Early Treatment Diabetic Retinopathy Study was reported. The data were compared with published literature in Indians using Stratus and Spectralis OCTs to assess variation in instrument measurements.

Results

The mean CFT in the study sample was 173.8 ± 18.16 microns (131–215 microns) and the mean PRL thickness was 65.48 ± 4.23 microns (56–74 microns). No significant difference (p = 0.148) was found between CFT measured automated (179.28 ± 22 microns) and manually (173.83 ± 18.1 microns). CFT was significantly lower in women (167.62 ± 16.36 microns) compared to men (180.03 ± 18 microns) (p = 0.008). Mean retinal thickness reported in this study was significantly different from published literature using Stratus OCT and Spectralis OCT.

Conclusion

We report the normal mean retinal thickness in central 1 mm area to be between 138 and 242 microns in Indian population using Copernicus SDOCT. We suggest that different OCT instruments cannot be used interchangeably for the measurement of macular thickness as they vary in segmentation algorithms.     

Retinal vessel diameters and their correlation with retinal nerve fiber layer thickness in patients with pseudoexfoliation syndrome

AIM: To compare retinal artery-vein diameters (RAVDs) of patients with pseudoexfoliation (PSX) syndrome with healthy controls and investigate the correlations between retinal nerve fiber layer (RNFL) thickness parameters and RAVDs. METHODS: Seventeen eyes with PSX and 17 eyes of age-matched controls were included in the study. All participants underwent routine ophthalmological examination, Humphrey visual field and RNFL examination by using Stratus OCT. Retinal images were obtained by using a retinal camera (Topcon 501X). RAVDs were measured from inferior nasal, inferior temporal, superior nasal and superior temporal arcuates by using IMAGEnet software. Superior, inferior, nasal, temporal and average RNFL thicknesses were recorded. RAVDs and RNFL parameters in groups and correlations were analyzed by Mann-Whitney U and Spearmann correlation tests. RESULTS: Only inferior quadrant and average RNFL thickness were detected thinner in the PSX group compared with control group (P=0.009, P=0.038, respectively). No statistically significant difference regarding RAVDs was found between two groups. CONCLUSION: RAVDs seems to be comparable in the PSX and control group. RNFL is thinner in the inferior quadrant in the PSX group. RNFL thickness and RAVDs show significant correlations in both groups. This correlation doesn’t seem to be specific to PSX.