The iStent® MIGS Family: iStent®, iStent Inject®, and iStent Supra®

  • Richard A. HillEmail author
  • David Haffner
  • Lilit Voskanyan


Microinvasive glaucoma surgeries or MIGS, an acronym coined by Ike Ahmed, represents a fundamental shift in glaucoma surgical philosophy. MIGS exploit existing physiologic outflow pathways allowing both rapid placement and visual recovery. The surgeon interacts with small anatomic functional structures in a minimally destructive manner. The first two Glaukos devices target trabecular outflow (iStenttm (G1) and iStenttm inject (G2)). The third targets uveoscleral outflow (iStenttm Supra (G3)). Theoretical modeling and ex vivo studies were used to study changes in trabecular outflow facility with multiple trabecular stents. This question is being studied clinically and 4000 iStentstm of all types in total have been placed in over 30 studies over the past 10 years. Two trabecular or two uveal scleral stents seem most favorable in terms of risks, costs, and effectiveness. There is also some advantage to using both trabecular and uveal scleral stents in eyes requiring lower target pressures.


Cataract Surgery Trabecular Meshwork Outflow Facility Peripheral Anterior Synechia Scleral Spur 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Supplementary material

Video 13.1

(M4V 26875 kb)

Video 13.2

(MP4 3577 kb)

Video 13.3

(WMV 562099 kb)

Video 13.4

(WMV 8352 kb)

Video 13.5

(WMV 8864 kb)

Video 13.6

(MPG 66496 kb)


  1. 1.
    Bahler C, Smedley G, Zhou J, Johnson D. Trabecular bypass stents decrease intraocular pressure in cultured human anterior segments. Am J Ophthalmol. 2004;138:988–94.PubMedCrossRefGoogle Scholar
  2. 2.
    Bahler C, Hann C, Fjield T, et al. Second-generation trabecular meshwork bypass stent (iStent inject) increases outflow facility in cultured human anterior segments. Am J Ophthalmol. 2012;153:1206–13.PubMedCrossRefGoogle Scholar
  3. 3.
    Fernández-Barrientos Y, Garcia-Feijoó J, Martinez de la Casa JM, et al. Fluorophotometric study of the effect of the Glaukos trabecular micro-bypass stent on aqueous humor dynamics. Invest Ophthalmol Vis Sci. 2010;51:3327–32.PubMedCrossRefGoogle Scholar
  4. 4.
    Hann CR, Fautsch MP. Preferential fluid flow in the human trabecular meshwork near collector channels. Invest Ophthalmol Vis Sci. 2009;50(4):1692–7.PubMedCentralPubMedCrossRefGoogle Scholar
  5. 5.
    Ichhpujani P, Katz LJ, Gille R, Affel E. Imaging modalities for localization of an iStent®. Ophthalmic Surg Lasers Imaging. 2010;41:660–3.PubMedCrossRefGoogle Scholar
  6. 6.
    Phares DJ, Smedley GT, Zhou J. Laminar flow resistance in short micro tubes. Int J Heat Fluid Flow. 2005;26:506–12.CrossRefGoogle Scholar
  7. 7.
    Phares DJ, Smedley GT. A study of laminar flow of polar liquids through circular micro tubes. Am Inst Phys. 2004;16:1267–72.Google Scholar
  8. 8.
    Zhou J, Smedley GT. Trabecular bypass: effect of Schlemm canal and collector channel dilation. J Glaucoma. 2006;15:446–55.PubMedCrossRefGoogle Scholar
  9. 9.
    Zhou J, Smedley GT. A trabecular bypass flow hypothesis. J Glaucoma. 2005;14:74–83.PubMedCrossRefGoogle Scholar
  10. 10.
    Arriola-Villalobos P, Martinez-de-la-Casa J, Fernandez-Perez J, et al. Combined iStent trabecular micro-bypass stent implantation and phacoemulsification for coexistent open- angle glaucoma and cataract: a long-term study. Br J Ophthalmol. 2012. doi: 10.1136/bjophthalmol-2011-300218.PubMedGoogle Scholar
  11. 11.
    Belovay GW, Naqi A, Chan BJ, Rateb M, Ahmed II. Using multiple trabecular micro-bypass stents in cataract patients to treat open-angle glaucoma. J Cataract Refract Surg. 2012;38:1911–7.PubMedCrossRefGoogle Scholar
  12. 12.
    Buchacra O, Duch S, Milla E, Stirbu O. One-year analysis of the iStent trabecular microbypass in secondary glaucoma. Clin Ophthalmol. 2011;5:321–6.PubMedCentralPubMedGoogle Scholar
  13. 13.
    Buznego C. Trabecular micro-bypass stent for glaucoma. Tech Ophthalmol. 2008;6:114–8.CrossRefGoogle Scholar
  14. 14.
    Craven ER, Katz LJ, Wells JM, Giamporcaro JE. Cataract surgery with trabecular micro-bypass stent implantation in patients with mild-to-moderate open-angle glaucoma and cataract: Two-year follow-up. J Cataract Refract Surg. 2012;38:1339–45.PubMedCrossRefGoogle Scholar
  15. 15.
    Fea AM. Phacoemulsification versus phacoemulsification with micro-bypass stent implantation in primary open-angle glaucoma. J Cataract Refract Surg. 2010;36:407–12.PubMedCrossRefGoogle Scholar
  16. 16.
    Fea A, Dogliani M, Macetta F, et al. The trabecular bypass stent in a pseudophakic glaucoma patient: a 1-year follow-up. Clin Ophthalmol. 2008;2:931–4.PubMedCentralPubMedCrossRefGoogle Scholar
  17. 17.
    Morales-Fernandez L, Martinez-De-La-Casa J, Diaz Valle D, et al. Glaukos® trabecular stent used to treat steroid-induced glaucoma. Eur J Ophthalmol. 2011. doi: 10.5301/ejo.5000073.Google Scholar
  18. 18.
    Nichamin LD. Glaukos iStent® trabecular micro-bypass. Middle East Afr J Ophthalmol. 2009;16:138–40.PubMedCentralPubMedCrossRefGoogle Scholar
  19. 19.
    Samuelson TW, Katz LJ, Wells JM, et al. Randomized evaluation of the trabecular micro-bypass stent with phacoemulsification in patients with glaucoma and cataract. Ophthalmology. 2011;118:459–67.PubMedCrossRefGoogle Scholar
  20. 20.
    Spiegel D, Wetzel W, Neuhann T, Sturmer J, Hoh H, Garcia-Feijoo J, Martinez de la casa JM, Garcia-Sanchez J. Coexistent primary open-angle glaucoma and cataract: interim analysis of a trabecular micro-bypass stent and concurrent cataract surgery. Eur J Ophthalmol. 2009;19:393–9.PubMedGoogle Scholar
  21. 21.
    Spiegel D, Garcia-Feijoo J, Garcia-Sanchez J, Lamielle H. Coexistent primary open-angle glaucoma and cataract: preliminary analysis of treatment by cataract surgery and the iStent trabecular micro-bypass stent. Adv Ther. 2008;25:453–64.PubMedCrossRefGoogle Scholar
  22. 22.
    Spiegel D, Wetzel W, Haffner DS, Hill RA. Initial clinical experience with the trabecular micro-bypass stent in patients with glaucoma. Adv Ther. 2007;24:161–70.PubMedCrossRefGoogle Scholar
  23. 23.
    Spiegel D, Kobuch K. Trabecular meshwork bypass tube shunt: initial case series. Br J Ophthalmol. 2002;86:1228–31.PubMedCentralPubMedCrossRefGoogle Scholar
  24. 24.
    Traverso CE, Papadia M, Scotto R, Bagnis A. iStent® trabecular micro-bypass stent for open angle glaucoma. Expert Rev Ophthalmol. 2010;5:443–50.CrossRefGoogle Scholar
  25. 25.
    Vandewalle E, Zeyen T, Stalmans I. The iStent® trabecular micro-bypass stent: a case series. Bull Soc Belge Ophtalmol. 2009;311:23–9.PubMedGoogle Scholar
  26. 26.
    Johnstone M, Annisa J, Martin E. Chapter 7: Aqueous veins and open angle glaucoma. In: Schacknow PN, Samples JR, editors. The Glaucomas. New York: Springer; 2010.Google Scholar

Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  • Richard A. Hill
    • 1
    Email author
  • David Haffner
    • 2
  • Lilit Voskanyan
    • 3
  1. 1.Orange County Glaucoma Inc.Santa AnnaUSA
  2. 2.Product Development, Glaukos Corp.Laguna HillsUSA
  3. 3.Glaucoma, S.V. Malayan Eye CenterYerevan, ArabkirArmenia

Personalised recommendations