Purpose:
To evaluate the influence of clear cornea phacoemulsificationon functional and morphological changes of filtering blebs inglaucomatous eyes with previous successful trabeculectomy.
Methods:
The clinical cases of 27 patients (36 eyes) who underwent clearcornea phacoemulsification after trabeculectomy for primaryangle closure glaucoma or open angle glaucoma were prospectivelyinvestigated. The patients are with or without glaucoma medication,most of their intraocular pressure (IOP) are under control.The filtering bleb morphology was evaluated by Ultrasound Biomicroscopy(UBM) before Phaco, and 8 day to 90 days after Phaco. The controlgroup consisted of patients with glaucoma after Phaco withoutprevious trabeculectomy. The mean IOP was recorded before andafter Phaco.Photographs of the blebs were obtained.(Fig 1)
Results:
The mean IOP decreased 13.5%, from 15.22±4.82 mmHg preoperativeto 13.17 ±3.46mmHg postoperative (p=0.002), and postoperativeglaucoma medication requirements are not changed. The mean depthof anterior chamber increased from 1.97±0.62 mm to 3.51±0.40mm (p=0.0002). The mean height of the bleb decreased from 1.29±0.44mm to 1.19 ±0.34mm (p=0.017), while the mean width ofdrainage entrance(arrow in Fig 2) maintain no statisticallysignificant change, from 0.81±0.35 mm to 0.80±0.19mm, p=0.755 .The mean IOP of the control group decreased 19.8%,from 20.21±3.52 mmHg to 16.20±2.28 mmHg.
Conclusions:
Phaco may influence the function and morphology of filteringbleb through flatten the bleb. The intraocular pressure of thepatients with filtering blebs after phaco may not decrease asmuch as the control group. The long term influence needs furtherinvestigation.
Keywords: anterior segment • cataract • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)