The role of the Ex-PRESS device implantation in the management of pseudophakic glaucoma

Abstract

Purpose: evaluation of the role of the ExPRESS device implantation in the management of pseudophakic glaucoma. Design: non-comparative case series study. Patients and methods: 6 eyes with pseudophakic glaucoma scheduled to undergo ExPRESS glaucoma filtration device. Each study patient underwent a complete ophthalmic examination preoperatively including full clinical history taking, VA measurement, autorefraction examination, slit lamp biomicroscopy of the anterior segment, IOP measurement using Goldmann applanation tonometer, gonioscopic examination to evaluate of the angle of AC, and ophthalmoscopy of the posterior segment using a direct ophthalmoscopy. All the patients were subjected to functional and structural evaluation by SAP (HFA 745i) for central 30-2 threshold test, endothelial cell evaluation by non-contact specular microscopy (Topcon specular microscope; SP-1P Version 1.20) for endothelial cell count and OCT scans (Topcon 3D OCT-2000) for peripapillary RNFL thickness measurements, ONH analysis and GCA. All patients included were having pseudophakic OAG. Patients were excluded if they were under 18 years old. All eyes underwent ExPRESS device implantation performed by the same surgeon for consistency, using the standardized technique for the procedure. A complete ophthalmologic follow-up examination included IOP measurement using Goldmann applanation tonometry, number of drugs required to attain IOP control and any associated complications was carried out postoperatively at the 1st and 3rd days, the end of 1st week, every month till the end of the 6th month and the end of 1st year. Best-corrected visual acuity (BCVA) was tested using Snellen chart, which was converted to LogMAR for statistical analysis. Criteria for success were defined as follows; Absolute success: IOP ≤21 mmHg without any medication, qualified success: IOP ≤21 mmHg with ocular hypotensive medications. VF test with SAP, specular microscopy and ONH analysis and GCA assessed with OCT were carried out one year postoperatively. Results: There were 4 eyes (80%) showed complete success (IOP <21mmHg without treatment) and 1 eyes (20%) showed qualified success (IOP <21 mmHg with anti-glaucoma medical treatment). There is a statistically significant reduction in IOP 1, 3, 6 months and one year postoperatively (P<0.001) with the most reduction in IOP observed at 6 months after surgery due to controlling all cases with IOP >21 mmHg using anti-glaucoma medications by this time. There is a statistically significant improvement of postoperative BCVA (P=0.002). Moreover, there is a statistically significant reduction of number of anti-glaucoma medications used postoperatively (P<0.001). For VF indices, there is a statistically significant improvement in both MD and PSD postoperatively (MD; P<0.001) (PSD; P=0.002). However; There is no significant improvement in the staging of glaucoma according to GSS2 (P=327). For OCT parameter, there is a statistically significant increase in the thickness of both RNFL and GCC (P<0.001). Furthermore, endothelial CD...