频域-OCT观测原发性闭角型青光眼患者视盘形态、视网膜神经纤维层及神经节细胞复合体的临床意义

Clinical significance of SD-OCT detecting visual disc morphous,retinal nerve fibre layer and ganglion cell complex of PACG

目的应用频域-OCT观测原发性闭角型青光眼(primary angle closed glaucoma,PACG)患者视盘形态、视网膜神经纤维层(retinal nerve fiber layer,RNFL)及黄斑区神经节细胞复合体(ganglion cell complex,GCC),分析其与视野平均缺损(mean deviation,MD)的相关性。方法选取35例60眼PACG患者,根据视野损害程度分为早期及中晚期2组,与33例正常人进行频域-OCT对比检查。测量视盘形态学参数、整体平均RNFL厚度(RNFL-Avg)、上方平均RNFL厚度(RNFL-Sup)、下方平均RNFL厚度(RNFL-Inf)、整体平均GCC的厚度(GCC-Avg)、上方平均GCC厚度(GCC-Sup)、下方平均GCC厚度(GCC-Inf),并分析青光眼患者组视野MD与RNFL、GCC的相关性。结果视盘各形态学参数在各期PACG组与正常对照组间的差异具有统计学意义(视盘面积F=14.29、P=0.000;视杯面积F=11.31、P=0.000;盘沿面积F=6.27、P=0.002;盘沿容积F=10.41、P=0.000;视神经盘容积F=3.53、P=0.034;视杯容积F=10.99、P=0.000;杯盘比F=8.64、P=0.000;杯盘纵比F=3.14、P=0.048;杯盘横比F=4.20、P=0.012)。其中视盘面积差异表现为两个PACG组均较正常对照组大,而两个PACG组间差异无统计学意义;其他各参数表现为:中晚期PACG组的视杯面积、视杯容积、杯盘比均比正常对照组显著增大;而盘沿面积、盘沿容积和视神经盘容积均比正常对照组显著减小。增大及缩小的程度与正常对照组比较,差异均具有统计学意义,变化符合PACG神经损害的特点;而早期PACG组在上述参数中与正常对照组之间的差异均无统计学意义(均为P>0.05)。对RNFL及GCC的分析中,PACG组与正常对照组间的差异具有统计学意义(RNFL-Avg F=9.79、P=0.000;RNFL-Sup F=6.48、P=0.002;RNFL-Inf F=7.54、P=0.001;GCC-Avg F=6.62、P=0.002;GCC-Sup F=5.69、P=0.005;GCC-Inf F=6.45、P=0.003)。组间两两比较发现:中晚期PACG组上述各参数与正常对照组的差异具有统计学意义(均为P<0.05);而早期PACG组各参数与正常对照组间的差异无统计学意义(均为P>0.05)。中晚期PACG组RNFL和GCC均与MD呈明显的正相关(r=0.689 5,P=0.001;r=0.527 1,P=0.010);早期PACG组RNFL及GCC与MD无相关性(r=-0.208 4、P=0.244;r=0.200 1、P=0.281)。结论频域-OCT是一种比较敏感的能够观察到视网膜结构改变的检查方法,但其对于早期青光眼的诊断仍具有局限性。

Objective To investigate the appearance of optic disc,retinal nerve fiber layer（RNFL） and macular ganglion cell complex（GCC） in primary angle closure glaucoma（PACG）,and analyze their relationship with mean defect（MD） of visual field. Methods Sixty eyes of 35 PACG patients were selected and separated into early-stage PACG group,moderate and advanced-stage PACG group by appearance of visual field damage. 33 normal eyes were controlled in the study. Optic disc parameter,average RNFL thickness（RNFL-Avg）,superior RNFL thickness（RNFL-Sup）,inferior RNFL thickness（ RNFL-Inf）,average GCC thickness（ GCC-Avg）,superior GCC thickness（GCC-Sup） and inferior GCC thickness（ GCC-Inf） were measured by SD-OCT. The correlation between MD and RNFL,GCC were evaluated and analyzed. Results Among the optic disc parameters,there were significant differences between PACG group and control group（Disc area F = 14. 29,P = 0. 000;Cup area F = 11. 31,P = 0. 000;Rim area F = 6. 27,P = 0. 002;Rim volume F = 10. 41,P =0. 000;Nerve head volume F = 3. 53,P = 0. 034;Cup volume F = 10. 99,P = 0. 000;C /D ratio F = 8. 64,P = 0. 000;C /D horizontal ratio F = 3. 14,P = 0. 048;C /D vertical ratio F = 4. 20,P = 0. 012）. The disc area in two PACG group were bigger than that in control group,but there was no statistical difference between two PACG groups. Others parameter showed the difference between moderate and advanced-stage PACG group and control group,no difference could be seen between early-stage PACG group and control group（all P〉 0.05）. Among the analysis of RNFL and GCC,significant differences were found between the control group and PACG group（RNFL-Avg F= 7. 79,P = 0. 000;RNFL-Sup F = 6. 48,P = 0. 002;RNFL-Inf F = 7. 54,P = 0. 001;GCC-Avg F = 6. 62,P = 0. 002;GCC-Sup F = 5.69,P = 0. 005;GCC-Inf F = 6. 45,P = 0. 003）. The differences were found between moderate and advanced-stage PACG group and control group（all P 〈0. 05）,no difference between early-stage PACG group and control group（ all P 〉0. 05）. The positive correlations were seen between MD and RNFL,GCC in moderate and advanced-stage PACG group（r = 0. 689 5,P = 0. 001;r = 0. 527 1,P = 0. 010）,but no correlations was seen in early-stage PACG group（r =- 0. 208 4,P = 0. 244;r = 0. 200 1,P = 0. 281）. Conclusion SD-OCT is a sensitivity way to observe the structure change of retina,but still had the limit in the early diagnose of early-stage PACG.