Grooved Glaucoma Drainage Devices That Continuously Deliver Cyclosporine A Decrease Postsurgical Scar Formation in Rabbit Eyes

Abstract

Citation: Dai Z, Yu X, Sun J, Sun X. Grooved glaucoma drainage devices that continuously deliver cyclosporine A decrease postsurgical scar formation in rabbit eyes. Invest Ophthalmol Vis Sci. 2017;58:169258: -170158: . DOI: 10.1167 PURPOSE. To study the functional outcomes of filtration surgery by implanting improved glaucoma drainage devices (GDDs) comprising surface grooves and a composite coating of cyclosporine A (CsA) and PLGA in experimental rabbit eyes.METHODS. Improved GDDs were designed and prepared by modifying normal GDD with surface grooves and a CsA-PLGA composite coating. Normal GDDs, grooved GDDs (G-GDDs), and GGDDs with a CsA-PLGA composite coating (CsA@G-GDD) were implanted into 18 rabbit eyes (six eyes per group). The intraocular pressure (IOP), bleb survival time, bleb morphology, and anterior chamber reactions were assessed for up to 12 weeks after GDD implantation. The IOPs were compared statistically among the three groups. Bleb morphology was quantified using the Indiana Bleb Appearance Grading Scale. Anterior chamber radiography was performed to check whether the filtrating pathway was blocked, and determine the drainage time and diffusion area of the contrast agent. Hematoxylin and eosin staining and immunohistochemistry were conducted to assess how the GDDs slowed or prevented scar formation.RESULTS. The improved GDDs were successfully prepared and implanted in 18 rabbit eyes without severe surgical complications. Bleb survival time was significantly longer and IOP was significantly lower in the G-GDD and CsA@G-GDD groups compared with the GDD group (all, P < 0.001). Blebs were significantly higher in the CsA@G-GDD group than in the GDD and G-GDD groups (P ¼ 0.003). Anterior chamber radiography revealed more unobstructed filtration channels in the CsA@G-GDD group than in the GDD group (P ¼ 0.032). Postsurgical scar formation was less extensive in the G-GDD and CsA@G-GDD groups than in the GDD group.CONCLUSIONS. Compared with the normal GDDs, G-GDDs with a CsA-PLGA coating inhibited postsurgical scar formation and improved the surgical success rate, and might represent an alternative to existing glaucoma filtration devices.Keywords: glaucoma drainage devices, cyclosporine A, groove, filtration surgery, scar formation G laucoma is characterized by elevated intraocular pressure (IOP) and frequently causes optic neuropathy. If left untreated, it causes chronic progressive degeneration of retinal ganglion cells and visual field loss.1,2 The treatment of glaucoma typically begins with topical medications and then filtering surgeries. 3 Glaucoma filtration surgery seeks to achieve incomplete healing to allow the aqueous humor to escape the eye, unlike other surgical procedures in which complete wound healing is desired. 4 Unfortunately, IOP often increases after surgery owing to scar formation in the wound field. The success rate of trabeculectomy was reported to be 64.7% over 5 years in eyes with open-angle glaucoma. 5 In complicated cases, implantation of a glaucoma drainage device (GDD) is...

Nanofiber‐based glaucoma drainage implant improves surgical outcomes by modulating fibroblast behavior

“…Fourteen and 28 days after implantation, bleb morphology was graded by examining sedated animals using the Indiana Bleb Appearance Grading Scale (IBAGS) to assign numerical scores for height, extent, and vascularity based on standardized photos. This method has previously been used in rabbit models of glaucoma surgery to evaluate bleb morphology in response to small molecule therapies and device‐specific modifications in preventing scar formation 68–71 . Implant migration was assessed by measuring the distance between the distal end of the GDI within the anterior chamber to the corneal limbus at baseline immediately after implantation, and then at 14 and 28 days post implantation.…”

“…This method has previously been used in rabbit models of glaucoma surgery to evaluate bleb morphology in response to small molecule therapies and device‐specific modifications in preventing scar formation. 68 , 69 , 70 , 71 Implant migration was assessed by measuring the distance between the distal end of the GDI within the anterior chamber to the corneal limbus at baseline immediately after implantation, and then at 14 and 28 days post implantation. For assessing GDI patency, rabbits were sedated and proparacaine hydrochloride drops were administered topically.…”

Ahmed implant coated with poly(2-methacryloyloxyethyl phosphorylcholine) inhibits foreign body reactions in rabbit eyes

“…Several studies have proposed different modifications to glaucoma drainage devices. The novel devices include an adjustable glaucoma device [ 19 ], a device delivering cyclosporine A [ 20 ] or MMC [ 21 ] for a certain period, and a device that contains a plate made of polymethyl methacrylate [ 22 ], or a plate replaced with microfluidic meshwork [ 23 ]. To our knowledge, this is the first preliminary study to demonstrate the use of a novel coating material for fibrosis inhibition in glaucoma implant surgery.…”