Clinical Research Of Intraocular Alteration Following Vitrectomy

Aim: In order to explore the possible alteration of refraction and estimate the potential impact of visual quality,we investigate the impact of intraocular structure between the simple operation and the combination of phacoemulsification&intraocular lens implantation.The influence was also observed among various tamponade materials application.Methods: Ultrasound biomicroscopy and IOL Master were measured for simple vitrectomy patients(the simple group, 37eyes) and vitrectomy combined with cataract surgery patients(the combined group,11eyes).The simple group was further divided into three sub-groups by various tamponade materials in vitreous:silicone oil group,gas group and equilibrium liquid group.Several parameters were measured such as the anterior chamber depth, anterior chamber angle, axial length, corneal curvature parameter and corneal thickness preoperatively and two weeks postoperatively.Results: AOD250, AOD500, TIA500 and AL were decreased 0.13 ±0.21 mm,0.16 ± 0.22 mm,8.68 ° ± 9.72 ° and 0.18 ± 0.24mm( P<0.05)respectively in the simple group postoperatively. ACD, AOD250, AOD500,TIA500 and AL in combined group increase 0.95±0.54mm?0.13±0.12mm?0.22±0.20mm?11.49°±11.06°and 0.45±0.30mm(P<0.05)respectively after operation.Alteration of ACD, AOD250, AOD500, TIA500 and AL were different between simple group and combined group(P<0.05).Of data from various tamponade materials sub-groups, ACD, AOD250, AOD500 and TIA500 of the gas group reduced 0.19±0.17mm?0.14±0.09mm?0.20±0.12 mm and12.02°±6.64°respectively after operation(P<0.05), the AOD250, AOD500,TIA500 and axial length of silicone oil group decreased 0.19±0.25mm?0.21 ± 0.26 mm ? 10.44 ° ± 9.67 ° and 0.23 ± 0.19 mm respectively after operation(P<0.05), while equilibrium liquid group have no significant changed in all intraocular structure(P>0.05).However,neither the corneal thickness nor curvature(K1?K2)were changed postoperatively(P>0.05).Conclusions: Alteration of anterior segment and axial length in combined group were different from that of the simple group,while the corneal thickness and corneal curvature(K1?K2)were not obviously changed in all groups.Meanwhile, various tamponade materials can also cause different impact to intraocular structure and refraction. In brief,alterations of intraocular structure might cause discrepant refractive changes and potential influence of visual quality.