Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Apr 27:16:1281-1288.
doi: 10.2147/OPTH.S307835. eCollection 2022.

A New and Easier Approach to Preserflo MicroShunt Implantation

Antonio M Fea  1 , Andrea Ghilardi  1 , Davide Bovone  1 , Michele Reibaldi  1 , Alessandro Rossi  1 , Earl R Craven  2
Affiliations

A New and Easier Approach to Preserflo MicroShunt Implantation

Antonio M Fea et al. Clin Ophthalmol. .

Abstract

PRESERFLO™ MicroShunt is a new minimally invasive glaucoma surgical (MIGS) device, implanted with an ab externo approach, which drains the aqueous humor to the subconjunctival space. It has been designed as a safer and less invasive approach for treating medically uncontrolled primary open-angle glaucoma (POAG) patients. The classic way of MicroShunt implantation involves different key steps, which includes creating a small scleral pocket with a 1mm blade; passing a 25-gauge (25G) needle through the scleral pocket into the anterior chamber (AC); and subsequently flushing the stent with a 23-gauge (23G) thin-wall cannula. However, sliding the needle into the scleral pocket can create false passages, thus making the device's threading more difficult. The purpose of the current paper is to propose a simplified implantation approach. Our method proposes to make the scleral tunnel by using directly the 25G needle and, at the limbus, this 25G needle is used to slightly depress the sclera and enter into the AC. The MicroShunt is subsequently assembled on a 23G cannula mounted on a 1mL syringe. The syringe can then be used to flush the device. Outflow can thus be confirmed immediately by seeing drops of aqueous humor leaking from the external opening of the stent. This new approach may have different potential advantages, such as better control of the site of entry, avoids wrong passages, reduces or eliminates the risk of aqueous humor sideway flow, facilitates a parallel path to the iris plane, and it is faster.

Keywords: MIGS; MicroShunt; Preserflo; glaucoma surgery; open-angle glaucoma; subconjunctival filtration surgery.

PubMed Disclaimer

Conflict of interest statement

Dr Antonio M Fea is consultant for Glaukos, Ivantis, iSTAR, EyeD, and personal fees from and consultant for AbbVie, outside the submitted work. Dr Earl R Craven is currently an employee for AbbVie and reports personal fees from Santen, outside the submitted work. The authors report no other conflicts of interest in this work.

Figures

Figure 1
Figure 1
Overview of the main steps of the new surgical technique. (A) The needle is aimed to pierce the sclera starting 3 mm from the limbus. (B) Once the needle has reached the limbus it is pushed downwards. (C) The needle goes into the anterior chamber. (D) Once the tunnel is created with the triangular blade, the path of the needle used to enter the anterior chamber may be not perfectly coaxial with the tunnel, thus creating a false passage.
Figure 2
Figure 2
Median intraocular pressure over the course of the study follow-up. Vertical bars represent interquartile range. *p < 0.005 as compared to baseline (Friedman test and post hoc analysis for pairwise comparisons were done with the Conover method).
Figure 3
Figure 3
Overview of the median best corrected distance visual acuity (BCDVA) over the course of the study follow-up. Vertical bars represent interquartile range. *p < 0.01 as compared to baseline (Friedman test and post hoc analysis for pairwise comparisons were done with the Conover method).
See this image and copyright information in PMC

References

    1. Ansari E. An update on implants for Minimally Invasive Glaucoma Surgery (MIGS). Ophthalmol Ther. 2017;6(2):233–241. doi:10.1007/s40123-017-0098-2 - DOI - PMC - PubMed
    1. Bar-David L, Blumenthal EZ. Evolution of glaucoma surgery in the last 25Years. Rambam Maimonides Med J. 2018;9(3):e0024. doi:10.5041/RMMJ.10345. - DOI - PMC - PubMed
    1. Mathew DJ, Buys YM. Minimally invasive glaucoma surgery: a critical appraisal of the literature. Annu Rev Vis Sci. 2020;6:47–89. doi:10.1146/annurev-vision-121219-081737 - DOI - PubMed
    1. Vinod K, Gedde SJ. Safety profile of minimally invasive glaucoma surgery. Curr Opin Ophthalmol. 2021;32(2):160–168. doi:10.1097/ICU.0000000000000731 - DOI - PubMed
    1. Pereira ICF, van de Wijdeven R, Wyss HM, et al. Conventional glaucoma implants and the new MIGS devices: a comprehensive review of current options and future directions. Eye. 2021;35(12):3202–3221. doi:10.1038/s41433-021-01595-x - DOI - PMC - PubMed