The Primary Study Of Changes Of The Structure Of Ocular Anterior Segment After Trabeculectomy With Ultrasound Biomicroscopy

Objective: To observe the changes of the structure of ocular anterior segment after trabeculectomy with ultrasound biomicroscopy(UBM) in acute angle-closure glaucoma and chronic angle-closure glaucoma.Methods: 26 patients(33 eyes)of acute angle-closure glaucoma and 25 patients(37 eyes)of chronic angle-closure glaucoma were underwent trabeculectomy.The structure of ocular anterior segment were separately observed and measured by using UBM before and after surgery, and compare the consistency of the chamber angles examined by UBM and goniscope. The parameters included anterior chamber distance(ACD), trabecular ciliary process distance(TCPD), iris-lens contact distanc(eILCD), iris-lens angle(θ2), iris-zonular distance(IZD), angle opening distance (AOD), open angle (AA), sclera-ciliary process angle(θ4).Results:1. Ciliary body detachment was found in 3 patients(3 eyes) preoperatively.The vision was no significant diferences preoperatively and postoperatively.2. The intraocular pressure (IOP) of all patients were controlled between 7 to 19 mmHg after surgery. The mean IOP was 12.1±3.6 mmHg.3. In acute angle-closure glaucoma patients, the chamber angle became wider by a goniscope postoperatively. In chronic angle-closure glaucoma patients, the chamber angle was nealy the same.4. The filtrable passage were determined by UBM 1 month after trabeculectomy. A echolessarea existed between conjunctiva flap and sclera flap. It seemed that aqueous homor flowed freely, and no ciliary body detachment was found.5. In acute angle-closure glaucoma patients, there were statistically significant differences between the preoperative and postoperative AOD, AA, ILCD,θ2, IZD (P<0.05). There were no significant differences between the preoperative and postoperative ACD, TCPD,θ4 (P>0.05), and there were 3 eyes with ciliary body detachment before surgery. In chronic angle-closure glaucoma patients, there were statistically significant differences between the preoperative and postoperative ILCD,θ2, IZD (P<0.05). There were no significant differences between the preoperative and postoperative ACD, AOD, AA, TCPD,θ4 (P>0.05).Conclusion:1. UBM is unique to observe the filtrable passage in vivo and estimate whether it's obstructed. It posses higher value in evaluating the function of filter bleb.2. Except AOD, AA, the other changes of the ocular anterior segment is similar. Pupillary block is relieved after trabeculectomy. But the risk factors of lens and ciliary body can't be relieved.3. UBM is good to find ciliary body detachment which conventional scan ultrasound can't collect. UBM is very important for instructing the therapy of glaucoma preoperatively and postoperatively.4. UBM is an exactly tool to measure the changes of the structure of ocular anterior segment after trabeculectomy. It posses higher diagnostic value in discussing mechanism of glaucoma, reducing postoperative complication and evaluating therapeutic effect.