Transient Intraocular Pressure Elevation During LASIK On The Apoptosis Of Retinal Ganglion Cells

Objective To observe effects of transient intraocular pressure elevation during LASIK on the apoptosis of the retinal ganglion cells。Methods 1.Animal model building:New Zealand rabbit received different duration of suction(20 seconds,45 seconds and 2 minutes) to induce intraocular pressure elevation by negative pressure generator(IOP＞65mmHg). Corneal epithelium was received eximer laser(- 9.00D,193nm,125mJ/cm2,10Hz).2. Apoptosis of the retinal ganglion cells observation:The experimental eyes of 48 anesthetizde new zealand rabbit received different duration of suction(20 seconds,45 seconds and 2 minutes) to induce intraocular pressure elevation(IOP＞65mmHg).each group was subdivided into instant,7,14 and 28d groups in term of the days after surgery.Apoptosis of RGCs was monitored by electron microscopy and TUNEL.Results 1.Apoptosis of the retinal ganglion cells observation:Apoptosis of RGCs was no significant difference in duration of suction(20 seconds,45 seconds and 2 minutes)by TUNEL。2.The pathology of every storey of retina changes:The structure of retina did not changde under light microscopy and electron microscopy after negative suction 20 seconds and 45 seconds,but those were visible disorder on instant and days 7 after suction 2 mintes,also they can recoveryed after 28 days.Conclusions General negative suction(20s,45s)during LASIK do not effect the subcellular structure of the retina and optic nerve,as well as result in the Apoptosis of the retinal ganglion cells. They are changed if negative suction duration prolongs such as 2 minutes.The longer suction duration,the more evidence the change of RNFL thickness,the more prolong the recovery periods.May be results in the apoptosis of the retinal ganglion cells.We think that suction duration within 45sis safe.