AIM: To explore the possible alteration of refraction and estimate the potential impact of visual quality, investigate the impact of intraocular structure between the simple operation and the combination of phacoemulsification and intraocular lens implantation, and observe the influence among various tamponade materials application.

METHODS: Ultrasound biomicroscopy(UBM)and intraocular len(IOL)Master were measured for simple vitrectomy patients(the simple group, 37 eyes)and vitrectomy combined with cataract surgery patients(the combined group, 11 eyes). Several parameters were measured such as the anterior chamber depth(ACD), angle opening distance(AOD), trabecular iris angle(TIA), axial length(AL), et al. 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. All patients were measured including ACD, AOD250, AOD500, TIA500, AL and corneal curvature(K1, K2)parameters preoperatively and 2wk postoperatively.

RESULTS: AOD250, AOD500, TIA500 and AL were decreased 0.13±0.21mm, 0.16±0.22mm, 8.68°±9.72° and 0.18±0.24mm(all P<0.05)respectively in the simple group postoperatively. ACD, AOD250, AOD500, TIA500 and AL in combined group increased 0.95±0.54mm, 0.13±0.12mm, 0.22±0.20mm, 11.49°±11.06°, and 0.45±0.30mm(all 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±0.12mm, and 12.02°±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±0.26mm, 10.44°±9.67° and 0.23±0.19mm respectively after operation(P<0.05), while equilibrium liquid group had 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).

CONCLUSION: Alteration of anterior segment and axial length in combined group are different from that of the simple group, while the corneal thickness and corneal curvature(K1, K2)are not obviously changed in all groups. Meanwhile, various tamponade materials can also cause different impact on intraocular structure and refraction. In brief, alterations of intraocular structure might cause discrepant refractive changes and potential influence of visual quality.