Assessment of a self-assembling peptide gel, SPG-178, in providing a clear operative field for trabeculectomy surgery for glaucoma in an animal model

Kenji Matsushita,Rumi Kawashima,Haruka Okada,Hirokazu Sakaguchi,Andrew J Quantock,Koji Uesugi,Kohji Nishida

doi:10.1038/s41598-020-68171-3

Kenji Matsushita, Rumi Kawashima + Show 5 more

Open Access

https://doi.org/10.1038/s41598-020-68171-3

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Abstract

The presence of blood during ophthalmic surgery is problematic, as it can obstruct a surgeon’s view of the operative field. This is particularly true when performing trabeculectomy surgery to enhance ocular fluid outflow and reduce intraocular pressure as a treatment for glaucoma, one of the most common vision loss conditions worldwide. In this study, we investigated the performance of a transparent, self-assembling peptide gel (SPG-178) and its ability to maintain visibility during trabeculectomy surgery. Unlike the hyaluronic acid gel commonly used in ophthalmic surgery, SPG-178 did not permit the ingress of blood into the gel itself. Rather, it forced blood to flow peripherally to the gel. Moreover, if bleeding occurred under the SPG-178 gel, perfusion with saline was able to effectively flush the blood away along the interface between the SPG-178 and the ocular tissue (in this case scleral) to clear the surgical field of view. In experimental trabeculectomy surgeries with mitomycin C used as an adjuvant, there were no differences in the postoperative recovery of intraocular pressure or bleb morphology with or without the use of SPG-178. SPG-178, therefore, when used in a gel formulation, represents a new material for use in intraocular surgery to ensure a clear operative field with likely beneficial treatment outcomes.

Highlights

The presence of blood during ophthalmic surgery is problematic, as it can obstruct a surgeon’s view of the operative field
In cases of glaucoma in which drug treatment is inappropriate owing to side effects of the medication, or in patients who experience an insufficient reduction of intraocular pressure (IOP), intraocular surgery can be performed to reduce the IOP8
The diffusion of blood into Viscoat, a hyaluronic acid gel commonly used for ophthalmic surgery, and into the SPG-178 gel was measured and found to be significantly suppressed in the SPG-178 case when compared to that of Viscoat (p = 0.002, p = 0.01 (0 min), p < 0.01 (2, 4, 6, 8, and 10 min after the immersion of each material in 2 ml of blood)) (Fig. 1)

Summary

Introduction

The presence of blood during ophthalmic surgery is problematic, as it can obstruct a surgeon’s view of the operative field This is true when performing trabeculectomy surgery to enhance ocular fluid outflow and reduce intraocular pressure as a treatment for glaucoma, one of the most common vision loss conditions worldwide. Ophthalmic surgery is susceptible to intraoperative bleeding because there are many arterioles present in the eye, and attempts at achieving hemostasis have met with limited success Techniques such as thermo-coagulation, for example, invariably result in the constriction of ocular tissues—especially the conjunctiva and sclera—which can have a detrimental impact on the surgery[7,8]. We investigate the use of a self-assembling peptide gel (SPG-178) as a novel material, which safeguards visibility during glaucoma surgery without the need for heat coagulation and the deleterious effects that accompany this. Taking advantage of the unique properties of the SPG-178, we report its use to ensure intraoperative visibility applicable to a wide range of ophthalmic operations, not least of which is surgery for glaucoma that, as mentioned, is prone to excessive bleeding

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