正常眼压性青光眼中视盘分区指标改变与视野改变间的关系

目的探讨应用海德堡视网膜断层扫描仪Ⅱ型(HRT-Ⅱ)检测正常眼压性青光眼(NTG)患者视盘分区指标改变及其与HFA-Ⅱ视野改变间的关系。方法26例(51只眼)NTG患者分别接受HRT-Ⅱ视盘立体测量与HFA-Ⅱ中央视野30-2阈值检测。观察患者上、下半侧视野损害与视盘颞上、颞下分区间损害程度的部位对应关系,比较视野早期损害组(EP)与视野损害前期组(PP)间视盘整体与视盘分区内视杯形状测度(CSM)、盘沿面积(RA)、盘沿容积(RV)、视杯平均深度(MCD)及笔者提出的视杯容积指数(CVI)共计5项视盘指标的差异,分析视盘对应分区内上述各项指标分别与各自视野指数(MD)间的相关性。结果视盘分区与半侧视野间损害程度的部位对应关系中,CVI、RA、RV、CSM及MCD5项指标的对应率依次为92.68%、87.80%、82.93%、63.41%及53.66%;CVI、RA及RV3项与CSM和MCD2项间的差异有统计学意义(P<0.05)。视野前期组和早期损害组的MD分别为(-0.0960±1.1920)dB和(-2.4070±1.1370)dB,差异有统计学意义(P<0.05),两组视盘分区内各项指标的差异也均有统计学意义(P<0.05),但视盘整体内各项指标的差异却均无统计学意义(P>0.05)。上述5项视盘指标中仅CSM与MD呈负相关(r=-0.3002,P<0.05),RA与MD呈正相关(r=0.3105,P<0.05),但相关程度均较弱。结论对于NTG患者的早期视野损害,视盘颞上或颞下分区内CSM、RA、RV、MCD及CVI5项指标比视盘整体内相应指标有更灵敏的提示作用。临床上应用HRT-Ⅱ检查视盘分区指标,与两种视野检查结果结合及比照有助于NTG的早期诊断。(中华眼科杂志,2006,42:204-208)

The interrelationship between the sectorial disc and the visual field changes in patients with normal tension glaucoma

OBJECTIVE: To investigate the changes of the sectorial discs and visual fields, and their interrelationships in patients with normal tension glaucoma (NTG). METHODS: 26 patients with NTG were undergone the optic nerve and visual field examinations with HRT-II and HFA II in a time interval of less than 5 months. The parameters in the study including cup shape measure (CSM), rim area (RA), rim volume (RV), mean cup depth (MCD) and cup volume index (CVI) were compared between the global discs and the sectorial discs in eyes with the evidences of preperimetric or early visual field defect (MD < or = 4 dB). The CVI was proposed to be equal to CV/(DA x MCD + RA x RNFLT), where DA was disc area and RNFLT was retinal nerve fiber layer thickness. The linear correlations were evaluated between the visual field MD and each of 5 parameters in sectorial discs. RESULTS: The sectorial disc areas were mostly in correspondence to the damaged hemifields (CVI: 92.68%, RA: 87.80%, RV: 82.93%). In addition, a correlation was seen for CSM and MCD (63.41% and 53.66%; chi2 = 23.17, P < 0.05). The comparison between preperimetric and early defects were significantly difference (t = 1.735 approximately 6.536, P < 0.05 approximately P < 0.05, one-sided t test). The correlation between CSM and MD was negative (r = -0.3002, P > 0.05), however the positive correlation was demonstrated in RA versus MD (r = 0.3105, P < 0.05). CONCLUSION: The examination of the 5 parameters of sectorial discs had even closer relationship than those of global discs scanning in the detection of early vision field defect and it is valuable in diagnosis of early glaucoma.