青光眼患者视网膜前膜对相干光层析成像术测量视网膜神经纤维层厚度的影响

Effect of epiretinal membrane on measurement of retinal nerve fiber layer thickness by optical coherence tomography in patients with glaucoma

目的探讨青光眼患者视网膜前膜(ERM)的发生早期对视盘周围视网膜神经纤维层(RNFL)厚度测量的影响。方法在定期随访的青光眼患者中,连续入组新诊断为ERM的患者。在ERM发病前后,用相干光层析成像术(OCT)测量RNFL厚度,并用Humphrey视野分析仪进行视野检查。主要评估RNFL厚度的变化和视野分析仪视野指数的变化。结果共入组32例(32只眼)。在发生ERM后RNFL厚度平均增加(4.0±7.7)μm(P=0.007)。上方、鼻侧和颞侧象限RNFL较发生ERM之前增加,颞侧RNFL厚度增加具有显著统计学差异(15.0±22.4)μm(P<0.001),但是下方象限RNFL厚度减少了(-0.6±6.9)μm(P=0.205)。在视野检查中视野平均缺损显著降低了(-0.9±1.6)dB(P=0.024),从-15.1 dB降至-16 dB。结论青光眼患者ERM发生后虽然视野平均缺损有所下降,但是RNFL平均厚度显著增加。当ERM发生在青光眼患者,临床医生应注意用OCT测量RNFL厚度可能低估青光眼视神经病变程度。

Objective To investigate the effect of early occurrence of epiretinal membrane(ERM)on the measurement of retinal nerve fiber layer(RNFL)thickness around the optic disc in patients with glaucoma.Methods Among glaucoma patients who were followed up regularly,patients with newly diagnosed ERM were enrolled continuously.Before and after the onset of ERM,the thickness of RNFL was measured by OCT,and the visual field was examined by Humphrey visual field analyzer.The change of RNFL thickness and the change of visual field index of visual field analyzer were evaluated.Results 32 cases(32 eyes)were enrolled.RNFL thickness increased by an average of(4.0±7.7)μm after ERM onset(P=0.007).RNFL in the upper,nasal and temporal quadrants increased compared with that before ERM onset,and the thickness of temporal RNFL increased significantly(4.0±7.7μm,P<0.001).However,the thickness of RNFL in the lower quadrant decreased by(-0.6±6.9)μm(P=0.205).In the visual field examination,the average visual field defect decreased significantly by(-0.9±1.6)dB(P=0.024),from-15.1 to-16 dB.Conclusions Although the average visual field defect decreased after ERM onset in glaucoma patients,the average thickness of RNFL increased significantly.When ERM occurs in glaucoma patients,clinicians should note that measuring RNFL thickness with OCT may underestimate the degree of glaucoma optic neuropathy.