Development of the shunt implantation technology in patients with open-angle glaucoma and clinical results

Abstract

Glaucoma continues to lead among the irreversible causes of blindness and low vision. In some cases, surgical treatment is the method of choice even for newly detected glaucoma. The indication for the use of drains is refractory glaucoma, but today microshunting is widely enough used in patients with primary open angle glaucoma at the first stage of surgical treatment.The aim of the study is to develop a technology of polymeric microshunt implantation and estimate the clinical effect of its using for the surgical treatment of worsening and terminal open‑angle glaucoma.Materials and Methods. 30 patients (30 eyes) with open‑angle glaucoma and high level of intraocular pressure (IOP) were observed. All the patients were given modified partial‑thickness deep sclerectomy with the polymeric microshunt implantation by means of the developed insertor. The shunt made of polymer (polycarbonate methacrylate) is a hollow square tube 2.5 mm long, the diameter of the inner hole is 0.2 mm. The needle cut angle is 45 degrees, the end of the needle has an additional lateral anti‑lock hole. The microshunt consists of two parts: the needle for placing into the anterior chamber and supporting elements for the shunt fixation between the superficial and deep layers of the sclera. The insertor we created is an instrument 12.2 mm long with the 2.2 mm long thin rod at the end. Before implantation the shunt put on the needle is securely fixed due to the working part of the tool cut (45 degrees), which is congruent to the external part of the shunt. After the implantation the needle is removed from the shunt by pressing the side button of the insertor that allows to leave the shunt at the implantation site.Results. All the patients demonstrated good results at a distant time with areactive current of postoperative period. Computer static projector perimetry and visometry didn’t reveal any negative dynamics during the entire observation period. According to ophthalmoscopy and optical coherent tomography results, the changes of the optic disc, ganglion cells layer in the macula and peripapillary nerve fibers remained at the same level.Conclusion. Antiglaucomatous surgery according to the invented technology of the polymeric shunt implantation with the help of the original insertor in combination with modified sclerectomy provides stable hypotensive effect and minimizes complications. In addition, the method helps to stabilize visual functions in patients with worsening and terminal open‑angle glaucoma and high level of IOP.