Prospective OCT evaluation of bleb morphology after transscleral XEN glaucoma gel stent implantation

Session Details

Session Title: Glaucoma II

Session Date/Time: Tuesday 08/09/2015 | 08:00-10:30

Paper Time: 09:04

Venue: Room 17

First Author: : M.Lenzhofer AUSTRIA

Co Author(s): :    H. Reitsamer   M. Hohensinn   C. Strohmaier              

Abstract Details

Purpose:

The transcleral XEN glaucoma gel stent is a minimally invasive ab interno implanted glaucoma implant (AqueSys Inc., CA, USA). The implant creates a fistula between anterior chamber and subconjuncitival space. In contrast to ab externo procedures, the XEN implantation does not require opening of the conjunctiva resulting in different bleb appearance. Anterior segment (AS) OCT technique shows features of bleb morphology not visible in slit lamp biomicroscopy. The present study aimed to show bleb morphology changes detected by AS-OCT after MIGS surgery in POAG patients.

Setting:

Approved by the local ethics committee, this prospective non randomized trial was conducted at the Department of Ophthalmology at Paracelsus Medical University, Salzburg, Austria.

Methods:

Data from 27 POAG eyes of 25 patients were collected at preoperative, 1 and 2 weeks, 1, 3, 6, 9 and 12 month postoperative. Postoperative visits included assessment of intraocular pressure, bleb presence in slit lamp examination and conventional AS-OCT (Visante OCT, Zeiss, Germany). Standardized intrableb morphologies and structures were categoreized into uniform, microcystic multiform, subconjunctival separation or multiple internal layers.

Results:

Postoperative a good IOP reduction could be detected. In slit lamp examination blebs were present in 81% (n=27) of the eyes at 1 week, decreasing to 52% (n=27) at the 1 month and rising to 82% (n=17) at 12 months. In AS-OCT 26% (n=27) of the eyes had visible blebs at 1 week, 7% (n=27) showed blebs at 1 month, and 18% (n=17) showed blebs at 12 months postoperative. In the categorization we detected mainly uniform bleb morphology (41% at 1 week, 52% at 2 weeks, 70% at 1 month, 65% at 12 months).

Conclusions:

The present study clearly demonstrates a different bleb appearance following XEN microstent implantation when compared to data of trabeculectomies from the scientific literature. Comparable studies indicate that only 20-30% (the best comparable study: 20.8%) of blebs after trabeculactomy show a uniform bleb morphology. Present data suggest uniform bleb morphology in 65% of patients after XEN glaucoma surgery. This may be explained by lower intraoperative trauma and the good tissue compatibility of the XEN gel implant.

Financial Interest:

NONE