Long follow-up study of the nerve fiber bundle damage in anterior ischemic optic neuropathy

Abstract

Objective To investigate the dynamics damage of the nerve fiber bundle and its effects on visual function in late phage of anterior ischemic optic neuropathy (AION),and confirm the clinical significance of taking further neuroprotective treatment.Methods Ninety-six patients (128 eyes)clinical diagnosed of anterior ischemic optic neuroipathy,through acute phage treatment and after becoming stable,were followed every 3-6 months and then every year one year later.For every followed time,the fundus,vision and visual field were examined and the thickness of nerve fiber layer was measured by OCT.The data were statistically analyzed and comparatively studied.Results (1) All patients were followed for 6～12 months,among them 72 cases were followed between 1 to 2 years,47 cases between 2 to 4 years,and 36 cases over 4 years.(2) There was no significant change of the optic atrophy and fundus during the followed time,8 cases (8.7％) developed anterior ischemic optic neuropathy in the fellow eye.(3) Exclude of the refraction and the other factors,there were no significant difference in visual acuity.(4) There was no significant change of the location and the form of visual field damage during the followed time,however the sensitivity decreased.(5) Compared to the first OCT inspection,the subsequent OCT inspection showed that the optic disc peripheral nerve fibers became thinner to different degree during the followed time.(6) During the followed time,the peripheral nerve fiber layer thickness and visual field sensitivity of the patients treated by the neuroprotective were better than those not treated.Conclusions In the late phage of NAION,the nerve fiber bundle are still damaged slowly.It is necessary to investigate the damage mechanism and take the neuroprotective treatment. Key words: Anterior Ischemic Optic Neuropathy; Optic nerve fiber