Posters

Morphology and function of filtering blebs after trabeculectomy with Ologen collagen matrix implants in steroid induced glaucoma

Poster Details

First Author: E.Kasimov AZERBAIJAN

Co Author(s):    F. Aghayeva              

Abstract Details

Purpose:

To analyse the morphologic appearance of filtering blebs (FB) after primary trabeculectomy with Ologen® collagen implant in patients with steroid induced glaucoma (SG) and define correlations between determined morphologic features and function of FB.

Setting:

National Centre of Ophthalmology, Baku, Azerbaijan.

Methods:

SG is refractory disastrous form of secondary glaucoma that can occur in 12,8% patients received systemic steroid treatment. Trabeculectomy remains the 'gold standard' surgical option in the treatment of SG refractory to maximal medical therapy. However late bleb failure occurs in 24-74% cases at 4 years follow-up. Ologen® Collagen Matrix promotes wound healing and thus leads to formation of physiologic, vascular bleb with maximal reduction of baseline IOP and minimal rate of postoperative complications. Evaluation of morphology and function of the FB with Ologen was performed in several clinical studies. This prospective study included 5 patients (5 eyes) with medically uncontrolled SG who underwent primary trabeculectomy with Ologen® collagen matrix implantation. The patients had been receiving steroid treatment because of the following reasons: systemic lupus erythematosus - 1 patient, rheumatoid poliarthritis - 2 cases, vernal catarrh - 2 cases. Morphologic appearance of FB and intraocular pressure (IOP) reduction were evaluated at 1, 3, 6, 9, 12 and 15 months after surgery. FB were analysed by using the Moorfields Bleb Grading System (MBGS) and anterior segment optical coherence tomography via Visante OCTTM.

Results:

The mean postoperative follow-up period was 15 months. The mean preoperative IOP decreased from 30 ± 2.1 mmHg to 12 ± 1.1 mmHg by postoperative month 15. Mean reduction in IOP was greater at 1 and 3 months. Mean height of the bleb, horizontal and vertical lengths of the internal cavity of the FB, internal cavity height and wall thickness were 1.52 ± 0.12 mm, 5.66 ± 0.33 and 5.59 ± 0.29 mm, 1.29 ± 0.13 mm and 0.25 ± 0.04 mm at 1 month after surgery. With Visante OCT imaging there was no significant difference in mean bleb height at 1, 3 and 6 months, but at 9 months and further bleb height began to decrease. The Ologen implants were still visible in Visante OCT images in 2 patients at 6 months. The mean FB wall thickness slightly increased from 0.25 mm (1st month) to 0.73 mm (15th month). With the MBGS there was no significant differences in maximal bleb area score and central bleb vascularity score during the follow-up, but bleb height score was significantly lower at 15 months after surgery. All the FB were present with the central bleb vascularity score from 2 to 4.

Conclusions:

There were revealed several differences in FB morphology and function at 9 months and further after surgery. Within 15 months of surgery, mean bleb height was significantly lower than FB height score at 1 month after surgery. The full degradation of the Ologen impants was only noted by postoperative month 12. Intrableb morphology identified by Visante OCT have been reported to show good correlation with clinical bleb grading and bleb function. Thus, the bleb morphologic features could provide objective data for evaluating the bleb function and outcome of antiglaucomatous surgery. FINANCIAL INTEREST: NONE