Abstract
Purpose :
To investigate the relationship between retroprosthetic membrane (RPM) formation and angle closure that commonly occurs after Boston type 1 Keratoprosthesis (KPro) implantation and is a major causative factor for elevated intraocular pressure (IOP), secondary glaucoma, and vision loss. RPM is the most common complication after KPro surgery and we believe it could play a causative role in development of angle closure in eyes with KPro.
Methods :
Retrospective chart review of 183 eyes that underwent KPro surgery at our institution was performed. Eyes with documented open angle by anterior segment optical coherence tomography (AS-OCT) at the time of KPro implantation were included in the study. Medical records and AS-OCT images were reviewed for the presence of RPM and synechial angle closure. The presence of RPM was evaluated clinically at the slit lamp (retro-optic) as well as by AS-OCT (retro backplate).
Results :
Fifteen eyes of 15 patients were included in the study. Mean age at the time of surgery was 53.3 years and mean follow up period was 4.3 years.Seven eyes developed RPM, all of which developed synechial angle closure evidenced by AS-OCT either concurrently or sequentially after RPM development, only one eye developed angle closure earlier than RPM after an episode of endophthalmitis. Of the 8 eyes without RPM formation, only one developed angle closure. The one eye that developed angle closure without RPM did so after pars plana vitrectomy for macula off retinal detachment. Fisher’s exact test was statistically significant for a positive association between RPM development and post-operative angle closure by AS-OCT (p<0.05).
Conclusions :
Glaucoma remains the leading cause of irreversible vision loss in eyes with KPro and progressive synechial angle closure is an important risk factor for the development and progression of glaucoma after KPro implantation. Our study shows a significant association between RPM development and progressive angle closure. Moreover, the development of RPM appears to precede that of angle closure. We hypothesize that RPM can creep into the peripheral anterior chamber and induce synechial closure of the angle. A larger study is needed to confirm our findings.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.