正常眼压性青光眼滤过性手术前后视盘形态和视野的变化

Changes of the optic disc morphology in HRT-Ⅱ and visual field after filter surgeries for normal tension glaucoma

目的观察青光眼滤过性手术对正常眼压性青光眼(NTG)视力、眼压、视盘形态和视野指数的影响,评估海德堡视网膜断层扫描仪(HRT-Ⅱ)在NTG随访应用中的价值。方法NTG患者32例(47只眼),其中17只眼进行滤过性手术治疗(S组),另30只眼未进行手术治疗(C组),正常对照30例(60只眼)(N组),N组、S组在治疗前和治疗后6个月时、C组在首诊时和6个月后分别进行眼科常规检查、HRT-Ⅱ和Humphrey视野计检查,记录视力、眼压、屈光度以及视盘形态和视野的参数,包括视杯面积(CA)、视盘面积(DA)、盘沿面积(RA)、视杯容积(CV)、盘沿容积(RV)、杯盘面积比(CDAR)、线性杯盘比(LCD)、平均视杯深度(MCD)、最大视杯深度(MaxCD)、视杯形态测量(CSM)、视杯高度变异轮廓(HVC)、平均视网膜神经纤维层厚度(MRNFLT)、视神经纤维层横截面积(RCSA)和平均视野缺损(MD)等参数,对比分析各组不同时间点各参数的差异。结果S组术前和术后6个月的视力差异无统计学意义(P>0.05),眼压明显降低(P<0.05),C组在首诊和随访6个月后的视力和眼压差异均无统计学意义(P>0.05)。S组术后6个月和C组随访6个月之间MD差异无统计学意义(P>0.05),6个月MD变化率比较,S组29.22%(17.07%)和C组27.28%(22.81%)之间差异无统计学意义(P>0.05)。S组术前和C组首诊时CA较正常组大(P<0.05),6个月CA变化率比较,S组3.12%(1.10%)小于C组12.38%(4.54%)(P<0.05)。S组术前和C组首诊时RA较N组RA小(P<0.05),S组变化率-1.33%(2.54%)与C组3.18%(3.36%)之间差异有统计学意义(P<0.05)。S组术后6个月的CDAR较C组随访6个月小(P<0.05),S组变化率13.19%(7.10%)和C组变化率8.82%(12.12%)之间差异无统计学意义(P>0.05)。S组术前和C组首诊时之间CSM、HVC、MRNFLT、RCSA比较差异无统计学意义(P>0.05),S组HVC变化率4.19%(2.55%)小于C组变化率7.33%(3.66%)(P<0.05),S组MRNFLT变化率1.79%(4.35%)小于C组变化率16.31%(11.57%)(P<0.05)。结论HRT-Ⅱ可以直观反映NTG视盘和视网膜神经纤维层厚度的细微变化;与药物治疗相比,滤过性手术可能更加有效延缓视神经改变的进一步发展。

Objective To study the effect of filter surgeries on the changes of visual acuity, intraocular pressure, structural parameters of the optic disc and the perimetric indices of Humphrey perimetry in normal tension glaucoma （ NTG ） subjects and to evaluate HRT- II in the follow-up of NTG patients. Methods Thirty-two NTG patients （47 eyes） and 30 healthy subjects （60 eyes ） were enrolled in the study and classified into three separate groups： 60 healthy eyes for normal control （N）, 17 NTG eyes to undergo filter surgeries （S） , 30 NTG eyes untreated with surgery as control （ C）. The normal control eyes, 17 NTG eyes treated with surgery before treatment and 6 months after treatment and 30 NTG eyes untreated at the first diagnosis and 6 months later were examined with ophthalmic routine examinations, HRT-II and Humphrey perimetry. Visual acuity, intraocular pressure, diopter and cup area （ CA）, disk area （ DA ）, rim area （ RA）, cup volume （CV）, rim volume （RV）, cup/disk area ratio （CDAR） , linear cup/disk ratio （LCDR）, mean cup depth （MCD） , maximum cup depth （MaxCD）, cup shape measure （CSM）, height variation contour （HVC）, mean RNFL thickness （MRN-FLT）, RNFL cross sectional area （RCSA） and mean defect （MD） values were obtained from the result reports. The differences of parameters between the 3 groups at various time points were comparatively analyzed with statistic software. Results Between pre-surgery and 6 mo after surgery in group S, there was no significant differences of visual acuity （ P 〉 0.05 ） while intraocular pressure decreased significantly （ P 〈 0.05 ）. No statistically significant differences of visual acuity and intraocular pressure were observed between at the first diagnosis and 6 months later of group C （ P 〉 0.05 ）. The MD value was not different at 6 mo between group S and group C （ P 〉 0.05 ） and there was no significant difference of change rates of MD value during 6 mo between group S 29.22% （ 17.07% ） and group C 27.28% （22.81%） （ P 〉 0.05 ）. The CA values of group S and C were larger than that of group N （P 〈0.05 ） and the increase rate of CA in group S 3.12% （ 1. 10% ） was lower than that in group C 12.38% （4.54%） （ P 〈0.05）. The RA values of group S and C were lower than that of group N （ P 〈 0.05 ） and the decrease rate of RA in group S - 8.33% （2.54%） was lower than that in group C 3. 18% （ 7.36% ） （ P 〈 0.05 ）. The CDAR value at 6 months after surgery were lower than that after 6 months of follow - up in group C （ P 〈 0.05 ）, but there was no significant difference of change rates of CDAR value during 6 mo between group S 13.19% （7.10% ） and group C 8.82% （ 12.12% ） （ P 〉 0.05 ）. There were no significant differences of the CSM, HVC MRNFLT, and RCSA values between pre-surgery in group S and the previous diagnosis in group C （ P 〉 0.05 ）. The increase rate of HVC in group S 4.19% （2.55%） was lower than that in group C 7.33% （ 3.66% ） （ P 〈 0.05 ） and the increase rate of MRNFLT in group S 1.79% （4.35% ） was lower than that in group C 16.31% （ 11.57%） （ P 〈 0.05 ）. Conclusion The subtle changes of optic disc and retinal nerve fiber layer can be detected precisely by HRT-II. By comparison with topical medications, the filter surgeries can delay the aggravation of neuropathy in NTG patient.