Evaluation Intraocular Pressure Elevation After Scleral Buckling Surgery In Patients With Rhegmatogenous Retinal Detachment Using Ultrasound Biomicroscopy

Objective:To evaluate the changes of ocular anterior segment values included anterior chamber depth (ACD), angle open distance (AOD) and central corneal thickness (CCT) measured by ultrasound biomicroscopy (UBM) after scleral buckling (SB) surgery in patients with rhegmatogenous retinal detachment (RRD).Then the relationship between intraocular pressure(IOP) evelation and these values were analyzed.Methods:56RRD patients operated with SB surgery were divided into two groups according to the IOP measured one day after the surgery:evelated IOP group (evelated IOP≥8mmHg) and stabled IOP group (evelated IOP<8mmHg).Changes of the values included ACD, AOD and CCT were compared, and then the relationship between IOP evelation and these values were analyzed. Results:1. After SB surgery, all patients reseted successfully,13patients occured with IOP evelation.Compared with the preoperative, IOP were evelated in both two groups postoperative (P<0.01), in evelated IOP group, IOP was evelated most obviously one day postoperative, and then decreased gradually, and evelated lower than8mmHg one week postoperative. IOP was no statistically significant between two grous preoperative (P>0.05), and obviously higher in evelated IOP group than stabled IOP group within three months postoperative (P<0.01), but there was no statistically significant after six months postoperative (P>0.05)2. Compared with the preoperative:ACD were reduced most obviously in both two groups one day postoperative, and then reseted gradually, in evelated IOP group, ACD was reduced within six months postoperative (P<0.01), in stabled IOP group, ACD was reduced within one month postoperative (P<0.01), still reduced three months postoperative (P<0.05), but there was no statistically significant after six months postoperative (P>0.05). ACD wsa obviously lower in evelated IOP group than stabled IOP group preoperative and postoperative (P<0.01)3. Compared with the preoperative:in both two groups, AOD were reduced most obviously one day postoperative, then reseted gradually, and still reduced within one month postoperative (P<0.01), but there were no statistically significant after three months postoperative (P>0.05). AOD was obviously lower in evelated IOP group than stabled IOP group preoperative and postoperative (P<0.01).4. Compared with the preoperative:in both two groups, CCT were thickened most obviously one day postoperative, then reseted gradually, and still reduced within one week postoperative (P<0.01), but there was no statistically significant after one month postoperative (P>0.05).CCT was no statistically significant between two grous preoperative (P>0.05), and obviously thickener in evelated IOP group than stabled IOP group within one week postoperative (P<0.05), but there was no statistically significant after one month postoperative (P>0.05)5. Optimal cut-off value of ACD preoperative to predict evelated IOP postoperative was2.96mm, sensitivity84.60%, specificity67.40%; Optimal cut-off value of AOD preoperative to predict evelated IOP postoperative was0.41mm, sensitivity92.30%, specificity86.00%.Conclusion:This study using UBM for evaluating the changes of ocular anterior segment values in patients with RRD after SB surgery, and then analyzed the relationship between IOP evelation and these values, the conclusion is as follows:1. IOP evelation mainly occurred early postoperative, and the effection was only temporary and reversible, the forward risk of glaucoma had not increased.2. Patients with narrow corner and shallow anterior chamber preoperative are more likely to have evelated IOP postoperatively. Optimal cut-off value of ACD preoperative to predict evelated IOP postoperative was2.96mm, sensitivity84.60%, specificity67.40%; Optimal cut-off value of AOD preoperative to predict evelated IOP postoperative was0.41mm, sensitivity92.30%, specificity86.00%. Evelated IOP is closely related to shallow anterior and narrow corner.3. CCT thichened was identified as the secondary change of evelated IOP and operation itself. 4. ACD restored relatively slow postoperative was mainly affected by IOP factors. ACD restored slower in evelated IOP group than stabled IOP.