PURPOSE: The purpose of the study is to evaluate the effectiveness, surgical preoperative and postoperative complications, histopathological findings, and optimize surgical technique after implantation of the new nanofiber glaucoma drainage implant (GDI). METHOD: Implantation of the GDI, a unique nanofiber drainage device fabricated from polyvinylidene fluoride (PVDF) using the well-established electrospinning technology on the Nanospider™ platform, was first optimized in vitro on cadaver porcine bulbs before the initial in vivo implantations. PVDF was selected due to its favorable properties, including biocompatibility, anti-adhesive behavior, and mechanical stability, which are particularly advantageous in minimizing fibroblast colonization and fibrotic encapsulation. The Nanospider™ technology allows for reproducible, large-scale fabrication of nanofiber materials with controlled fiber morphology, which ensures uniformity and precision of implant dimensions. An in vivo study on 28 normotensive eyes from 14 laboratory New Zealand White rabbits was conducted. There were two groups of animals: the study group (14 eyes) and the control group (14 contralateral eyes). The study group underwent implantation of the new nanofiber GDI; the control group did not undergo any surgical procedure. Intraocular pressure (IOP) was measured preoperatively and at regular times postoperatively (Tono-Pen AVIA®). Preoperative and immediate postoperative complications were monitored. Histological quantification was performed using unbiased sampling and stereological methods to assess leukocyte infiltration, type I and type III collagen fractions, and both absolute and relative levels of inflammation. RESULTS: Based on the previous results and in vitro surgical experiences, the implant was narrowed to 2.0 mm, a thickness of 100 µm was chosen, and the implant was fixed with two scleral stitches to maintain its position. No serious preoperative complications occurred during in vivo experiments. There was one extrusion of the glaucoma implant noted after surgery, likely due to insufficient conjunctival fixation. This animal was excluded from both the study and the control groups. No serious instances of intraocular hypotension were observed after surgery. All animals tolerated the surgical procedure well, and the postoperative period was without any serious issues. In the study group, the average preoperative IOP was 13.6 mmHg (±4.1, n = 13). The average postoperative IOP on the first day, one, two, and three weeks, and one month after surgery decreased to 8.8 mmHg (±3.3, n = 13), 9.8 mmHg (±2.0, n = 13), 10.3 mmHg (±3.6, n = 13), 10.2 mmHg (±2.6, n = 13), and 9.7 mmHg (±2.0, n = 13), respectively. In the control group of contralateral eyes, the average preoperative IOP was 11.42 mmHg (±4.2, n = 13). The average postoperative IOP was 11.8 mmHg (±5.4, n = 13), 14.2 mmHg (±4.6, n = 13), 14.5 mmHg (±3.4, n = 13), 14.0 mmHg (±3.8, n = 13), and 14.2 mmHg (±2.4, n = 13), respectively, at the same follow-ups. In the study group, the IOP was statistically significantly lower by 29% at the end of the follow-up compared to the preoperative measurements (p = 0.009). Eyes with the implant showed greater leukocyte infiltration and less type I collagen compared to the group without implants. The ratio of type I to type III collagen was lower in the implant group, indicating delayed maturation and weaker connective tissue during early healing. CONCLUSION: For easier implantation, minor technical adjustments such as implant narrowing and scleral fixation of the GDI were developed and tested using in vitro experiments. In vivo implantation of unique nanofiber GDI appeared safe and technically well-suited for our study. No serious perioperative or postoperative complications were observed. There was one scleral extrusion of the device, which was, in our opinion, caused by insufficient conjunctival fixation. A statistically significant IOP reduction was achieved at the end of the follow-up in the study group with implanted GDIs. Further studies on the effectiveness of the implant with longer monitoring periods, together with other surgical options such as combined cataract surgery and nanofibers GDI, are needed.

Biomedical Center Faculty of Medicine in Pilsen Charles University Prague Czech Republic

Department of Histology and Embryology Faculty of Medicine in Pilsen Charles University Prague Czech Republic

Department of Nonwovens and Nanofibrous Materials Technical University of Liberec Faculty of Textile Engineering Liberec Czech Republic

Ophthalmology Department 3rd Medical Faculty Charles University and University Hospital Kralovske Vinohrady Prague Czech Republic

Ophthalmology Department Klaudians Hospital Mlada Boleslav Czech Republic

Ophthalmology Department Medical Faculty Slovak Medical University in Bratislava Bratislava Slovak Republic

Zobrazit více v PubMed

Hložánek M, Ošmera J, Ležatková P, Sedláčková P, Filouš A. The retinal nerve fibre layer thickness in glaucomatous hydrophthalmic eyes assessed by scanning laser polarimetry with variable corneal compensation in comparison with age-matched healthy children. Acta Ophthalmol. 2012;90(8):709–12. doi: 10.1111/j.1755-3768.2011.02133.x PubMed DOI

O’Callaghan J, Cassidy PS, Humphries P. Open-angle glaucoma: therapeutically targeting the extracellular matrix of the conventional outflow pathway. Expert Opin Ther Targets. 2017;21(11):1037–50. doi: 10.1080/14728222.2017.1386174 PubMed DOI

Mietzner R, Breunig M. Causative glaucoma treatment: promising targets and delivery systems. Drug Discov Today. 2019;24(8):1606–13. doi: 10.1016/j.drudis.2019.03.017 PubMed DOI

Klézlová A, Bulíř P, Klápšťová A, Netuková M, Šenková K, Horáková J, et al. Novel Biomaterials in Glaucoma Treatment. Biomedicines. 2024;12(4):813. PubMed PMC

Klapstova A, Horakova J, Tunak M, Shynkarenko A, Erben J, Hlavata J, et al. A PVDF electrospun antifibrotic composite for use as a glaucoma drainage implant. Mater Sci Eng C Mater Biol Appl. 2021;119:111637. doi: 10.1016/j.msec.2020.111637 PubMed DOI

Klinge U, Klosterhalfen B, Ottinger AP, Junge K, Schumpelick V. PVDF as a new polymer for the construction of surgical meshes. Biomaterials. 2002;23(16):3487–93. doi: 10.1016/s0142-9612(02)00070-4 PubMed DOI

Urban E, King MW, Guidoin R, Laroche G, Marois Y, Martin L, et al. Why make monofilament sutures out of polyvinylidene fluoride? ASAIO J. 1994;40(2):145–56. doi: 10.1097/00002480-199404000-00006 PubMed DOI

Horakova J, Mikes P, Saman A, Jencova V, Klapstova A, Svarcova T, et al. The effect of ethylene oxide sterilization on electrospun vascular grafts made from biodegradable polyesters. Mater Sci Eng C Mater Biol Appl. 2018;92:132–42. doi: 10.1016/j.msec.2018.06.041 PubMed DOI

Runge J, Kischkel S, Keiler J, Grabow N, Schmitz K-P, Siewert S, et al. Experimental glaucoma microstent implantation in two animal models and human donor eyes-an ex vivo micro-computed tomography-based evaluation of applicability. Quant Imaging Med Surg. 2024;14(8):5321–32. doi: 10.21037/qims-23-905 PubMed DOI PMC

Bancroft JD, Gamble M. Theory and Practice of Histological Techniques. 6th ed. Churchill Livingstone: Elsevier; 2008.

Kocová J. Overall staining of connective tissue and the muscular layer of vessels. Folia Morphol (Praha). 1970;18(3):293–5. PubMed

Rich L, Whittaker P. Collagen and picrosirius red staining: A polarized light assessment of fibrillar hue and spatial distribution. J Morphol Sci. 2005;22:97–104.

Kolinko Y, Malečková A, Kochová P, Grajciarová M, Blassová T, Kural T, et al. Using virtual microscopy for the development of sampling strategies in quantitative histology and design-based stereology. Anat Histol Embryol. 2022;51(1):3–22. doi: 10.1111/ahe.12765 PubMed DOI

Howard V, Reed M. Unbiased Stereology. Garland Science. 2004. doi: 10.4324/9780203006399 DOI

Grajciarová M, Turek D, Malečková A, Pálek R, Liška V, Tomášek P, et al. Are ovine and porcine carotid arteries equivalent animal models for experimental cardiac surgery: A quantitative histological comparison. Ann Anat. 2022;242:151910. doi: 10.1016/j.aanat.2022.151910 PubMed DOI

Vaňková L, Křížková V, Grajciarová M, Hátlová V, Hecová L, Štefková M, et al. Scleral reactions to different suture materials: A comparative quantitative histological study in a rabbit model. Animal Model Exp Med. 2025;8(6):1119–29. doi: 10.1002/ame2.70036 PubMed DOI PMC

Echavez M, Agulto M, Veloso IM. Intravitreal bevacizumab as adjunctive therapy for bleb survival in trabeculectomy in rabbit eyes. Philipp J Ophthalmol. 2012;37:45–51.

García-Feijóo J, Larrosa JM, Martínez-de-la-Casa JM, Polo V, Julvez LP. Redefining minimally invasive glaucoma surgery. Minimally penetrating glaucoma surgery. Arch Soc Esp Oftalmol (Engl Ed). 2018;93(4):157–9. doi: 10.1016/j.oftal.2017.11.005 PubMed DOI

Razeghinejad MR, Havens SJ, Katz LJ. Trabeculectomy bleb-associated infections. Surv Ophthalmol. 2017;62(5):591–610. doi: 10.1016/j.survophthal.2017.01.009 PubMed DOI

Lockwood A, Brocchini S, Khaw PT. New developments in the pharmacological modulation of wound healing after glaucoma filtration surgery. Curr Opin Pharmacol. 2013;13(1):65–71. doi: 10.1016/j.coph.2012.10.008 PubMed DOI

Conlon R, Saheb H, Ahmed IIK. Glaucoma treatment trends: a review. Can J Ophthalmol. 2017;52(1):114–24. doi: 10.1016/j.jcjo.2016.07.013 PubMed DOI

Parikh KS, Josyula A, Omiadze R, Ahn JY, Ha Y, Ensign LM, et al. Nano-structured glaucoma drainage implant safely and significantly reduces intraocular pressure in rabbits via post-operative outflow modulation. Sci Rep. 2020;10(1):12911. doi: 10.1038/s41598-020-69687-4 PubMed DOI PMC

Mahale A, Othman MW, Al Shahwan S, Al Jadaan I, Owaydha O, Khan Z, et al. Altered expression of fibrosis genes in capsules of failed Ahmed glaucoma valve implants. PLoS One. 2015;10(4):e0122409. doi: 10.1371/journal.pone.0122409 PubMed DOI PMC

Schlunck G, Meyer-ter-Vehn T, Klink T, Grehn F. Conjunctival fibrosis following filtering glaucoma surgery. Exp Eye Res. 2016;142:76–82. doi: 10.1016/j.exer.2015.03.021 PubMed DOI

Vera V, Sheybani A, Lindfield D, Stalmans I, Ahmed IIK. Recommendations for the management of elevated intraocular pressure due to bleb fibrosis after XEN gel stent implantation. Clin Ophthalmol. 2019;13:685–94. doi: 10.2147/OPTH.S195457 PubMed DOI PMC

Chow A, McCrea L, Kimball E, Schaub J, Quigley H, Pitha I. Dasatinib inhibits peripapillary scleral myofibroblast differentiation. Exp Eye Res. 2020;194:107999. doi: 10.1016/j.exer.2020.107999 PubMed DOI PMC

Yu-Wai-Man C, Owen N, Lees J, Tagalakis AD, Hart SL, Webster AR, et al. Genome-wide RNA-Sequencing analysis identifies a distinct fibrosis gene signature in the conjunctiva after glaucoma surgery. Sci Rep. 2017;7(1):5644. doi: 10.1038/s41598-017-05780-5 PubMed DOI PMC

Stahnke T, Löbler M, Kastner C, Stachs O, Wree A, Sternberg K, et al. Different fibroblast subpopulations of the eye: a therapeutic target to prevent postoperative fibrosis in glaucoma therapy. Exp Eye Res. 2012;100:88–97. doi: 10.1016/j.exer.2012.04.015 PubMed DOI

Van Bergen T, Vandewalle E, Van de Veire S, Dewerchin M, Stassen J-M, Moons L, et al. The role of different VEGF isoforms in scar formation after glaucoma filtration surgery. Exp Eye Res. 2011;93(5):689–99. doi: 10.1016/j.exer.2011.08.016 PubMed DOI

Pitha I, Oglesby E, Chow A, Kimball E, Pease ME, Schaub J, et al. Rho-Kinase Inhibition Reduces Myofibroblast Differentiation and Proliferation of Scleral Fibroblasts Induced by Transforming Growth Factor β and Experimental Glaucoma. Transl Vis Sci Technol. 2018;7(6):6. doi: 10.1167/tvst.7.6.6 PubMed DOI PMC

Josyula A, Mozzer A, Szeto J, Ha Y, Richmond N, Chung SW, et al. Nanofiber-based glaucoma drainage implant improves surgical outcomes by modulating fibroblast behavior. Bioeng Transl Med. 2023;8(3):e10487. doi: 10.1002/btm2.10487 PubMed DOI PMC

Sacchi M, Tomaselli D, Ruggeri ML, Aiello FB, Sabella P, Dore S, et al. Fighting Bleb Fibrosis After Glaucoma Surgery: Updated Focus on Key Players and Novel Targets for Therapy. Int J Mol Sci. 2025;26(5):2327. doi: 10.3390/ijms26052327 PubMed DOI PMC