Filtering blebs after XEN implantation and trabeculectomy: a clinical and in vivo confocal microscopy study

Abstract

PurposeThe aim of this study was to evaluate and compare macroscopic and microscopic morphological features of functioning filtering blebs after XEN Gel Stent (XEN) implantation and trabeculectomy.MethodsProspective, observational case‐control study of 10 eyes submitted to XEN implantation, 10 eyes submitted to trabeculectomy and 11 control eyes treated medically. A complete ophthalmological examination was performed, including Goldmann applanation tonometry, slit‐lamp examination, anterior segment photography and in vivo confocal microscopy (IVCM – Heidelberg Retina Tomograph II, Rostock Cornea Module). Photographs were analyzed with Moorfields bleb grading system classification. The IVCM images were analyzed for the density of intraepithelial microcysts, the density of subepithelial connective tissue, the number, diameter and tortuousity of blood vessels and the presence of inflammatory cells. The examinations were performed from 6 to 16 months postoperatively and only blebs resulting from a surgery with total success were included (Intraocular pressure <21 mmHg without therapy).ResultsThe analyze of anterior segment photographs didn't showed diferences between blebs's features after XEN implantation and trabeculectomy. The IVCM showed an increase in the density of intraepithelial microcysts and subepithelial connective tissue in XEN and trabeculectomy blebs comparing with the controls (p < 0.05). All morphological findings were similar when comparing the group of XEN and trabeculectomy blebs.ConclusionsFunctioning blebs after XEN implantation showed similar features comparing with functioning blebs after trabeculectomy. Further longitudinal studies are needed to increase the postsurgery understanding and management of filtering blebs.