Misconduct Control on Perfusion Pressure During Vitrectomy Caused by Retinal Ischemia-Reperfusion Injury Can Lead to Loss of Visual Function after Operation

Yijie Chou¹, Yan Meng², Yungliang Cao³, Zhi Qu⁴, Yun Ying Gao⁵

Chengdu Kangqiao Eye Hospital^1,4,5, Medical College of Qingdao universit, Medical College of Weifang Shandong³

Purpose: to discussion for Reason of Loss of visual function after vitrectomy

Methods: 1, Report a cases that visual acuity was lost after vitrectomy and analysis
relationship between loss of visual function and retinal ischemia-reperfusion injur（ RIRI）； 2, Test Result Reports:suckling pig eyes,According to stipulated procedure of vitrectomy, to detect relationship between the height of infusion bottle and IOP and retinal blood circulation; 3, report on the Histopathological fruit of the pig eyes of RIRI by Light and electronmicroscopy.

Results: 1 With the height of the infusion bottle enhancement, A corresponding increase in IOP ,but the retinal blood flow was Corresponding reduction；when the height of infusion bottle more than 90cm, the blood flow of the retina Will completely stop; retina in ischemia; the height of the perfusion bottle down to 60cm below, then blood flow to resume; 2 retinal histology of RIRI finding : early, retinal edema, GCL chromatin density, nuclear membrane is not complete, mitochondrial vacuolar degeneration and medullary changes, with prolongation of reperfusion, the cell atrophy, degeneration, necrosis , retinal ganglion cells (RGCS) was reduced from 24.80 +2.78 a / per field to 15.00 +2.74 a / per field (P <0.01). in accord with the histology of RIRI.

Conclusion: during Vitrectomy, if the height of infusion bottle＞ 90cm，When more than perfusion pressure within the eye，Likely to cause retinal ischemia-reperfusion injury, in turn lead to reduction or even loss of visual function after surgery