Experimental study on the effect of high intraocular pressure after LASIK negative suction on the corneal surface morphology

Abstract

Objective To investigate the effect of high intraocular pressure (IOP) after LASIK negative suction on human corneal surface morphology and to infer the relationship between high IOP and post-LASIK keratectasia,secondary keratoconus.Methods Twenty-four New Zealand rabbits (48 eyes) were received negative suction 60 seconds according to LASIK negative suction,there' s no corneal flap making and no laser cutting.The change of anterior and posterior corneal surface height and anterior corneal surface curvature were observed after negative suction immediately,1hour,4 hours,17 hours,and 24 hours on corneal topography.Results The data of 24 rabbits (48eyes)'s anterior and posterior comeal surface height and anterior corneal surface curvature after negative suction 60s immediately,1 hour,4 hours,17 hours increased comparing with suction before,the difference being statistically different.While 24 hours' data gradually recovered,the difference being not statistically significant.Conclusions High IOP after LASIK negative suction can cause the height of anterior and posterior corneal surface increase,the curvature of anterior corneal surface enlarge and corneal lordosis,but changes return to normal after negative suction 24 hours. Key words: High intraocular pressure; Corneal surface morphology; LASIK; Excimer laser; Negative suction