Central retinal artery occlusion. Retinal survival time.

摘要: Abstract Purpose . To investigate the retinal survival time following central artery occlusion (CRAO). Methods In 38 elderly, atherosclerotic and hypertensive rhesus monkeys, transient CRAO (varying from 97 to 240 min) was produced by temporarily clamping CRA at its site of entry into optic nerve. Stereoscopic color fundus photography, fluorescein angiography, electroretinography (ERG), visual evoked potential (VEP) recording were performed before during clamping, after unclamping, serially thereafter. After unclamping CRA, animals followed for variable lengths (median duration 8·14 weeks). Finally, eyes nerves examined histologically. The data on ERG changes analyzed in four frames: (1) baseline (2) (3) immediately (4) end follow-up. Duration divided groups: 97, 105–120, 150–165, ≥180 min. Results A ‘negative ERG’ appeared clamping. With removal clamp, there b-wave recovery, with differential rates recovery ERG-eyes shorter recovered sooner than those longer occlusion. On seen scotopic 24 dB b-wave, photopic 0 dB single flash 30 Hz flicker, b/a ratio combined rod cone response selective showing statistically significant differences amongst periods CRAO. delayed normalization depressed reperfusion may indicate high-grade ischemic damage. At final follow-up test session, no clear-cut derangement any parameter group, subtotal amplitude all groups. Longer incomplete VEP recovery. histology, macular retina, min showed practically damage, but found be significantly associated amount damage ganglion cell layer ( p =0·009) inner nuclear =0·017). Outer plexiform layers photoreceptors There association measures histologic residual circulation variables. Conclusions Our electrophysiologic, histopathologic morphometric studies that retina old, atherosclerotic, monkeys suffers detectable above level, CRAO, more extensive irreversible study suggests lasting about results massive