Anterior segment optical coherence tomography and in vivo confocal microscopy imaging of conjunctival filtering blebs after XEN gel stent implantation: predictive factors of bleb functionality 1 year results

Session Details

Session Title: Glaucoma I

Session Date/Time: Sunday 11/09/2016 | 14:30-16:00

Paper Time: 15:48

Venue: Auditorium C6

First Author: : R.Spinetta ITALY

Co Author(s): :    V. Aragno   G. Consolandi   F. Germinetti   T. Rolle   F. Maria        

Abstract Details

Purpose:

The Aquesys Xen Gel Stent is a new minimally invasive ab interno filtering device . This procedure shunts the aqueous(HA) from the anterior chamber in the subconjunctival space, resulting in a bleb formation in the superonasal conjunctiva. Aim of this study was to assess the efficacy and safety of this device after a year of follow up(FU) and to provide a micro and macroscopic analysis by in vivo confocal microscopy (IVCM) and anterior segment OCT (AS-OCT) of the filtering bleb to identify predictive factors of efficacy or failure of this surgery.

Setting:

Department of Surgical Sciences, Ophthalmic Clinic, University of Turin, Turin, Italy .

Methods:

12 eyes of 11 patients affected by uncontrolled POAG with maximal medical therapy underwent stent implantation. Intraocular pressure(IOP), best corrected visual acuity(BVCA),endothelial cell density,mean deviation(MD) at Humphrey perimetry,bleb morphology at biomicroscopy, conjunctival IVCM and AS-OCT were assessed preoperatively and in the one year FU. Mean density (MMD,cysts/mm2) and area(µm2) of conjunctival microcysts and density of subepithelial connective tissue were evaluated by IVCM and quantified by the ImageJ software . AS-OCT assessed the appropriate placement of the device, bleb wall reflectivity and HA drainage. Complete success was defined as an IOP<18 mmHg, qualified IOP<18 mmHg on medication, unsuccess IOP>18mmHg on medication.

Results:

12months after surgery Aquesys Xen Gel was complete successful in 5 eyes (50%), qualified successful in 5eyes(50%),unsuccessful in 1 eye(0,83%).One patient was lost at FU. Mean IOP decreased from 21,79±2,78 to 15,18±2,18mmHg(p<0.001). BCVA,MD and endothelial cell density didn't change(p>0.05).Mean MMD significantly increased(p<0.01) in the nasal conjunctiva. Microcysts showed a clustered pattern rather than the diffuse pattern found preoperativly. The AS- OCT showed the appropriate placement of the device in all eyes. Any AS-OCT and biomicroscopy variable significantly changed. Nasal and central connective density at IVCM and bleb wall reflectivity at AS-OCT were significantly lower in complete success patients(p<0.05)than in unsuccess

Conclusions:

the Xen Gel stent provides a satisfactory IOP control with a significant reduction of IOP and of the number of medications used and it shows a good safety profile. A loosely arranged subepithelial connective tissue is the main predictive factor of successful surgery as showed by the lower connective density and bleb wall reflectivity observed by IVCM and AS-OCT respectively in success patients. By means of IVCM and AS-OCT imaging clinicians can control wound healing processes like fibrosis in the course of FU. These methodics may be employed in postoperative screening of failing implant, providing an additional aid to surgeons

Financial Disclosure:

NONE