Czech and Slovak Ophthalmology 381 10.31348/2025/35 Original article Clinical Outcomes of Preserflo MicroShunt versus Trabeculectomy: A Retrospective 6-Month Study Majtánová Nora https://orcid.org/0000-0002-9794-2277 Takáčová Adriana https://orcid.org/0009-0006-2802-6490 Herdová Lucia https://orcid.org/0009-0000-0245-133X Kurilová Veronika https://orcid.org/0000-0001-8791-5761 Majtán Juraj https://orcid.org/0000-0002-7268-1584 Fellner Zlatica https://orcid.org/0009-0000-9298-1595 Cholevík Dalibor https://orcid.org/0000-0002-9412-8579 Kolář Petr https://orcid.org/0000-0003-3709-4648 20 8 2025 2 3

Objective: To characterize and compare the efficacy and safety of trabeculectomy and Preserflo microshunt (PMS) implantation in patients with open-angle glaucoma. Material and Methods: This retrospective 6-month study included 100 eyes (100 patients). The 100 patients were divided into two groups of 50 patients, who were randomly assigned to either trabeculectomy or PMS implantation with mmC (0.4 mg/ml) applied using saturated sponges. The patients attended follow-up checks at 1, 8, 30, and 90 days postoperatively and at 6 months postoperatively. Endothelial cells were assessed at 3 and 6 months respectively. The main observed parameters were intraocular pressure (IOP), best corrected visual acuity (BCVA), anterior chamber depth (ACD), corneal hysteresis (CH), corneal endothelial cell density (CECD), coefficient of variation (CV), and antiglaucoma treatment. Results: In patients after trabeculectomy and after PMS implantation a comparable reduction in mean IOP values ​​of 40.2% and 45.8% respectively ​​was recorded for both surgical approaches in comparison with the preoperative mean IOP values. In all the studied patients, regardless of the type of surgical procedure, a significant reduction of CECD values was recorded 6 months after surgery. However, PMS implantation led to a greater reduction in antiglaucoma treatment postoperatively compared to trabeculectomy. Qualified success was almost identical in the case of both operations throughout the entire course, complete success was higher in favor of PMS at the beginning of the observation, but their values converged or met from approximately day 90 to month 6. Conclusion: The performed clinical evaluation of the efficacy and safety of PMS implantation compared to the classical surgical approach using trabeculectomy showed positive results related primarily to the reduction of postoperative complications, while maintaining the effectiveness of the surgical procedure. However, further clinical studies with a longer follow-up period are needed in order to provide long-term evidence of clinical efficacy.

 glaucoma trabeculectomy Preserflo MicroShunt antiglaucoma drugs References Vision Loss Expert Group of the Global Burden of Disease Study. Global estimates on the number of people blind or visually impaired by glaucoma: A meta-analysis from 2000 to 2020. Eye. 2024;38:2036. Chen W, Xu Y, Liu Z, Zhao J. Global, regional and national burden of Glaucoma: an update analysis from the Global Burden of Disease Study 2019. Int Ophthalmol. 2024;44:234. Ramulu PY, Corcoran KJ, Corcoran SL, Robin AL. Utilization of various glaucoma surgeries and procedures in Medicare beneficiaries from 1995 to 2004. Ophthalmology. 2007;114:2265-2270. Kalarn S, Le T, Rhee DJ. The role of trabeculectomy in the era of minimally invasive glaucoma surgery. Curr Opin Ophthalmol. 2022;33:112-118. Tanna AP. 2023-2024 Basic and Clinical Science Course, Section 10: Glaucoma: American Academy of Ophthalmology; 2023. Ichhpujani P, Singla E, Kalra G, Bhartiya S, Kumar S. Surgical trends in glaucoma management: the current Indian scenario. Int Ophthalmol. 2022;42:1661-1668. Pinchuk L, Riss I, Batlle JF, et al. The development of a microshunt made from poly(styrene-block-isobutylene-block-styrene) to treat glaucoma. J Biomed Mater Res B Appl Biomater. 2017;105:211-221. Governatori L, Oliverio L, Mermoud A, et al. PreserFlo MicroShunt versus trabeculectomy: an updated meta-analysis and systematic review. Graefes Arch Clin Exp Ophthalmol. 2024. DOI: 10.1007/ s00417-00024-06649-w Khan A, Khan AU. Comparing the safety and efficacy of Preserflo Microshunt implantation and trabeculectomy for glaucoma: A systematic review and meta‐analysis. Acta Ophthalmol (Copenh). 2024;102:e443-e451. Cairns JE. Trabeculectomy. Preliminary report of a new method. Am J Ophthalmol. 1968;66:673-679. Ng WS, Jayaram H. Adjunctive modulation of wound healing during cataract surgery to promote survival of a previous trabeculectomy. Cochrane Database Syst Rev. 2021;8:CD013664. Addicks EM, Quigley HA, Green WR, Robin AL. Histologic characteristics of filtering blebs in glaucomatous eyes. Arch Ophthalmol. 1983;101:795-798. Fluorouracil Filtering Surgery Study one-year follow-up. The Fluorouracil Filtering Surgery Study Group. Am J Ophthalmol. 1989;108(6):625-635. Lee GA, Liu L, Casson RJ, Danesh-Meyer HV, Shah P, ANZGS Trabeculectomy Consensus Group. Current practice of trabeculectomy in a cohort of experienced glaucoma surgeons in Australia and New Zealand. Eye. 2023;37:1139-1144. Wilkins M, Indar A, Wormald R. Intra-operative mitomycin C for glaucoma surgery. Cochrane Database Syst Rev. 2005;2005:CD002897. Wolters JEJ, van Mechelen RJS, Al Majidi R, et al. History, presence, and future of mitomycin C in glaucoma filtration surgery. Curr Opin Ophthalmol. 2021;32. Bindlish R, Condon GP, Schlosser JD, D’Antonio J, Lauer KB, Lehrer R. Efficacy and safety of mitomycin-C in primary trabeculectomy: five-year follow-up. Ophthalmology. 2002;109:1336-1341. Mosaed S, Dustin L, Minckler DS. Comparative outcomes between newer and older surgeries for glaucoma. Trans Am Ophthalmol Soc. 2009;107:127-133. Seol BR, Lee SY, Kim YJ, Kim YK, Jeoung JW, Park KH. Comparison of the efficacy and safety of trabeculectomy with mitomycin C according to concentration: a prospective randomized clinical trial. J Clin Med. 2020;10:59. Kitazawa Y, Suemori-Matsushita H, Yamamoto T, Kawase K. Low-dose and high-dose mitomycin trabeculectomy as an initial surgery in primary open-angle glaucoma. Ophthalmology. 1993;100:1624-1628. Mietz H, Krieglstein GK. Three-year follow-up of trabeculectomies performed with different concentrations of mitomycin-C. Ophthalmic Surg Lasers. 1998;29:628-634. Khan SA, Whittaker K, Razzaq MA, Arain UR. National survey of intraoperative mitomycin C use during trabeculectomy surgery in the UK. Int Ophthalmol. 2021;41:1309-1316. Zhang X, Song Y, Liebmann J, Weinreb RN. A modified technique in applying sponge soaked with mitomycin C in trabeculectomy. Asian Pacific Journal of Ophthalmology. 2021;10:548-552. Khaw PT, Chiang M, Shah P, Sii F, Lockwood A, Khalili A. Enhanced trabeculectomy: the moorfields safer surgery system. Dev Ophthalmol. 2012;50:1-28. Guimarães ME, de Pádua Soares Bezerra B, de Miranda Cordeiro F, et al. Glaucoma surgery with soaked sponges with mitomycin C vs Sub-Tenon injection: short-term outcomes. Journal of Current Glaucoma Practice. 2019;13:50-54. Gambini G, Carlà mm, Giannuzzi F, et al. PreserFlo® MicroShunt: an overview of this minimally invasive device for open-angle glaucoma. Vision (Basel). 2022;6:12. Nobl M, Freissinger S, Kassumeh S, Priglinger S, Mackert MJ. One-year outcomes of microshunt implantation in pseudoexfoliation glaucoma. PLoS One. 2021;16:e0256670. Triolo G, Wang J, Aguilar-Munoa S, Jayaram H, Barton K. Preserflo microshunt implant for the treatment of refractory uveitic glaucoma: 36-month outcomes. Eye. 2023;37:2535-2541. Storp JJ, Vietmeier FE, Merté RL, et al. Long-term outcomes of the PRESERFLO MicroShunt implant in a heterogeneous glaucoma cohort. J Clin Med. 2023;12:4474. Pillunat KR, Herber R, Haase MA, Jamke M, Jasper CS, Pillunat LE. PRESERFLO™ MicroShunt versus trabeculectomy: first results on efficacy and safety. Acta Ophthalmol (Copenh). 2022;100:e779-e790. Gubser PA, Pfeiffer V, Hug S, et al. PRESERFLO MicroShunt implantation versus trabeculectomy for primary open-angle glaucoma: a two-year follow-up study. Eye Vis (Lond). 2023;10:50. Rabiolo A, Toscani R, Sacchi M, et al. Risk factors for failure in glaucoma patients undergoing microshunt implantantion. Am J Ophthalmol. 2023;259:117-130. Burgos-Blasco B, García-Feijóo J, Gines-Gallego C, et al. Efficacy and safety of the PreserFlo implant with mitomycin C in childhood glaucoma after previous failed glaucoma surgeries. Graefes Arch Clin Exp Ophthalmol. 2023;261:1349-1357. Van Lancker L, Saravanan A, Abu-Bakra M, et al. Clinical outcomes and cost analysis of PreserFlo versus trabeculectomy for glaucoma management in the United Kingdom. Ophthalmol Glaucoma. 2023;6:342-357. Baker ND, Barnebey HS, Moster MR, et al. Ab-Externo MicroShunt versus trabeculectomy in primary open-angle glaucoma: one-year results from a 2-year randomized, multicenter study. Ophthalmology. 2021;128:1710-1721. Higashide T, Nishino T, Sakaguchi K, Yamada Y, Sugiyama K. Determinants of corneal endothelial cell loss after trabeculectomy with mitomycin C. J Glaucoma. 2019;28:61-67. Hirooka K, Nitta E, Ukegawa K, Sato S, Kiuchi Y. Effect of trabeculectomy on corneal endothelial cell loss. Br J Ophthalmol. 2020;104:376-380. Storr-Paulsen T, Norregaard JC, Ahmed S, Storr-Paulsen A. Corneal endothelial cell loss after mitomycin C-augmented trabeculectomy. J Glaucoma. 2008;17:654-657. Arnavielle S, Lafontaine PO, Bidot S, Creuzot-Garcher C, D’Athis P, Bron AM. Corneal endothelial cell changes after trabeculectomy and deep sclerectomy. J Glaucoma. 2007;16:324-328. Ibarz-Barberá M, Morales-Fernández L, Corroto-Cuadrado A, et al. Corneal endothelial cell loss after PRESERFLO™ MicroShunt implantation in the anterior chamber: anterior segment OCT tube location as a risk factor. Ophthalmol Ther. 2022;11:293-310. Steindor FA, Trigaux C, Holtmann C, Spaniol K, Geerling G, Borrelli M. PRESERFLO MicroShunt®: efficacy and endothelial cell density. J Glaucoma. 2023: doi: 10.1097/IJG.0000000000002325.10.1097/IJG.0000000000002325 No authors listed. The Advanced Glaucoma Intervention Study (AGIS): 7. The relationship between control of intraocular pressure and visual field deterioration.The AGIS Investigators. Am J Ophthalmol. 2000;130:429-440. Van Bergen T, Van de Velde S, Vandewalle E, Moons L, Stalmans I. Improving patient outcomes following glaucoma surgery: state of the art and future perspectives. Clin Ophthalmol. 2014;2:857-867. Khaw PT, Bouremel Y, Brocchini S, Henein C. The control of conjunctival fibrosis as a paradigm for the prevention of ocular fibrosis-related blindness. “Fibrosis has many friends”. Eye. 2020;34:2163- 2174. Grewal DS, Jain R, Kumar H, Grewal SP. Evaluation of subconjunctival bevacizumab as an adjunct to trabeculectomy a pilot study. Ophthalmology. 2008;115:2141-2145. Fakhraie G, Ghadimi H, Eslami Y, et al. Short-term results of trabeculectomy using adjunctive intracameral bevacizumab: a randomized controlled trial J Glaucoma. 2016;25:e182-e188. Akkan JU, Cilsim S. Role of subconjunctival bevacizumab as an adjuvant to primary trabeculectomy: a prospective randomized comparative 1-year follow-up study. J Glaucoma. 2015;24:1-8. Pro MJ, Freidl KB, Neylan CJ, Sawchyn AK, Wizov SS, Moster MR. Ranibizumab versus mitomycin C in primary trabeculectomy – a pilot study. Curr Eye Res. 2015;40:510-505. Kiddee W, Orapiriyakul L, Kittigoonpaisan K, Tantisarasart T, Wangsupadilok B. Efficacy of adjunctive subconjunctival bevacizumab on the outcomes of primary trabeculectomy with mitomycin C: a prospective randomized placebo-controlled trial. J Glaucoma. 2015;24:600-606. Andrés-Guerrero V, Perucho-González L, García-Feijoo J, et al. Current perspectives on the use of anti-VEGF drugs as adjuvant therapy in glaucoma. Adv Ther. 2017;34:378-395. Liu W, Liu B. Efficacy of anti-vascular endothelial growth factor and mitomycin C on wound healing after trabeculectomy in glaucoma patients: a meta-analysis. Int Wound J. 2023: doi: 10.1111/ iwj.14517. Zhou X, Chen J, Luo W, Du Y. Short-term outcomes of trabeculectomy with or without anti-VEGF in patients with neovascular glaucoma: a systematic review and meta-analysis. Translational Vision Science and Technology. 2023;12:12. Khaw PT, Chiang M, Shah P, Sii F, Lockwood A, Khalili A. Enhanced trabeculectomy: the moorfields safer surgery system. Dev Ophthalmol. 2017;59:15-35. Schlunck G, Meyer-ter-Vehn T, Klink T, Grehn F. Conjunctival fibrosis following filtering glaucoma surgery. Exp Eye Res. 2016;142:76- 82. Wells AP, Crowston JG, Marks J, et al. A pilot study of a system for grading of drainage blebs after glaucoma surgery. J Glaucoma. 2004;13:454-460.