Journal of Current Glaucoma Practice

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VOLUME 15 , ISSUE 2 ( May-August, 2021 ) > List of Articles


Minimally Invasive Glaucoma Surgery—to Remove or Preserve the Trabecular Meshwork: That is the Question?

Karthikeyan Mahalingam

Citation Information : Mahalingam K. Minimally Invasive Glaucoma Surgery—to Remove or Preserve the Trabecular Meshwork: That is the Question?. J Curr Glaucoma Pract 2021; 15 (2):47-51.

DOI: 10.5005/jp-journals-10078-1299

License: CC BY-NC 4.0

Published Online: 30-09-2021

Copyright Statement:  Copyright © 2021; The Author(s).


  1. Gould DB, Smith RS, John SWM. Anterior segment development relevant to glaucoma. Int J Dev Biol 2004;48(8-9):1015–1029. DOI: 10.1387/ijdb.041865dg.
  2. Hamanaka T, Bill A, Ichinohasama R, et al. Aspects of the development of Schlemm's canal. Exp Eye Res 1992;55(3):479–488. DOI: 10.1016/0014-4835(92)90121-8.
  3. Abu-Hassan DW, Acott TS, Kelley MJ. The trabecular meshwork: a basic review of form and function. J Ocul Biol 2014;2(1). DOI: 10.13188/2334-2838.1000017Available from:
  4. Buffault J, Labbé A, Hamard P, et al. The trabecular meshwork: Structure, function and clinical implications. A review of the literature. J Fr Ophtalmol 2020;43(7):e217–e230. DOI: 10.1016/j.jfo.2020.05.002.
  5. Johnstone MA. The aqueous outflow system as a mechanical pump: evidence from examination of tissue and aqueous movement in human and non-human primates. J Glaucoma 2004;13(5):421–438. DOI: 10.1097/01.ijg.0000131757.63542.24.
  6. Johnstone M, Xin C, Tan J, et al. Aqueous outflow regulation – 21st century concepts. Prog Retin Eye Res 2020. 100917. DOI: 10.1016/j.preteyeres.2020.100917.
  7. Johnstone MA, Grant WG. Pressure-dependent changes in structures of the aqueous outflow system of human and monkey eyes. Am J Ophthalmol 1973;75(3):365–383. DOI: 10.1016/0002-9394(73)91145-8.
  8. Grant WM. Further studies on facility of flow through the trabecular meshwork. AMA Arch Ophthalmol 1958;60(4 Part 1):523–533. DOI: 10.1001/archopht.1958.00940080541001.
  9. Grant WM. Experimental aqueous perfusion in enucleated human eyes. Arch Ophthalmol 1963;69(6):783–801. DOI: 10.1001/archopht.1963.00960040789022.
  10. Ellingsen BA, Grant WM. Trabeculotomy and sinusotomy in enucleated human eyes. Invest Ophthalmol 1972;11(1):21–28.
  11. Van Buskirk EM, Grant WM. Lens depression and aqueous outflow in enucleated primate eyes. Am J Ophthalmol 1973;76(5):632–640. DOI: 10.1016/0002-9394(73)90555-2.
  12. Rosenquist R, Epstein D, Melamed S, et al. Outflow resistance of enucleated human eyes at two different perfusion pressures and different extents of trabeculotomy. Curr Eye Res 1989;8(12):1233–1240. DOI: 10.3109/02713688909013902.
  13. Wecker T, Anton A, Neuburger M, et al. Trabeculotomy opening size and IOP reduction after Trabectome® surgery. Graefes Arch Clin Exp Ophthalmol 2017;255(8):1643–1650. DOI: 10.1007/s00417-017-3683-0.
  14. Manabe S-I, Sawaguchi S, Hayashi K. The effect of the extent of the incision in the Schlemm canal on the surgical outcomes of suture trabeculotomy for open-angle glaucoma. Jpn J Ophthalmol 2017;61(1):99–104. DOI: 10.1007/s10384-016-0487-4.
  15. Hirabayashi MT, Lee D, King JT, et al. Comparison of surgical outcomes of 360° circumferential trabeculotomy versus sectoral excisional goniotomy with the Kahook dual blade at 6 months. Clin Ophthalmol 2019;13:2017–2024. DOI: 10.2147/OPTH.S208468.
  16. Johnson M, Chan D, Read AT, et al. The pore density in the inner wall endothelium of Schlemm's canal of glaucomatous eyes. Invest Ophthalmol Vis Sci 2002;43(9):2950–2955.
  17. Buller C, Johnson D. Segmental variability of the trabecular meshwork in normal and glaucomatous eyes. Invest Ophthalmol Vis Sci 1994;35(11):3841–3851.
  18. Smith R. A new technique for opening the canal of Schlemm. Preliminary report Br J Ophthalmol 1960;44(6):370–373. DOI: 10.1136/bjo.44.6.370.
  19. McPherson SD, McFarland D. External trabeculotomy for developmental glaucoma. Ophthalmology 1980;87(4):302–305. DOI: 10.1016/s0161-6420(80)35233-0.
  20. Grehn F. The value of trabeculotomy in glaucoma surgery. Curr Opin Ophthalmol 1995;6(2):52–60. DOI: 10.1097/00055735-199504000-00009.
  21. Grover DS, Fellman RL. Gonioscopy-assisted transluminal trabeculotomy (GATT): thermal suture modification with a dye-stained rounded tip. J Glaucoma 2016;25(6):501–504. DOI: 10.1097/IJG.0000000000000325.
  22. Grover DS, Godfrey DG, Smith O, et al. Gonioscopy-assisted transluminal trabeculotomy, ab interno trabeculotomy: technique report and preliminary results. Ophthalmology 2014;121(4):855–861. DOI: 10.1016/j.ophtha.2013.11.001.
  23. Grover DS, Godfrey DG, Smith O, et al. Outcomes of gonioscopy-assisted transluminal trabeculotomy (GATT) in eyes with prior incisional glaucoma surgery. J Glaucoma 2017;26(1):41–45. DOI: 10.1097/IJG.0000000000000564.
  24. Richter GM, Coleman AL. Minimally invasive glaucoma surgery: current status and future prospects. Clin Ophthalmol 2016;10:189–206. DOI: 10.2147/OPTH.S80490.
  25. Allen L, Burian HM. Trabeculotomy ab externo. A new glaucoma operation: technique and results of experimental surgery. Am J Ophthalmol 1962;53(1):19–26. DOI: 10.1016/0002-9394(62) 90388-4.
  26. Quigley HA. Results, with trabeculotomy and study of reversible cupping. Ophthalmology 1982;89(3):219–226. DOI: 10.1016/s0161-6420(82)34803-4.
  27. Tanito M. Microhook ab interno trabeculotomy, a novel minimally invasive glaucoma surgery. Clin Ophthalmol 2017;12:43–48. DOI: 10.2147/OPTH.S152406.
  28. Dorairaj S, Tam MD. Kahook dual blade excisional goniotomy and goniosynechialysis combined with phacoemulsification for angle-closure glaucoma: 6-month results. J Glaucoma 2019;28(7):643–646. DOI: 10.1097/IJG.0000000000001256.
  29. Salinas L, Chaudhary A, Berdahl JP, et al. Goniotomy using the Kahook dual blade in severe and refractory glaucoma: 6-month outcomes. J Glaucoma 2018;27(10):849–855. DOI: 10.1097/IJG.0000000000001019.
  30. Wakil SM, Birnbaum F, Vu DM, et al. Efficacy and safety of a single-use dual blade goniotomy: 18-month results. J Cataract Refract Surg 2020;46(10):1408–1415. DOI: 10.1097/j.jcrs.0000000000000263.
  31. Conlon R, Saheb H, Ahmed IIK. Glaucoma treatment trends: a review. Can J Ophthalmol 2017;52(1):114–124. DOI: 10.1016/j.jcjo.2016. 07.013.
  32. Espinoza G, Rodriguez-Una I, Pedraza-Concha A. A case of bilateral delayed-onset hyphema following pupil dilation after gonioscopy-assisted transluminal trabeculotomy. J Curr Glaucoma Pract 2020;14(2):72–75. DOI: 10.5005/jp-journals-10078-1279.
  33. Chihara E, Chihara T. Turn back elevation of once reduced IOP after trabeculotomy ab externo and Kahook dual blade surgeries combined with cataract surgery. OPTH 2020;14:4359–4368. DOI: 10.2147/OPTH.S287090.
  34. Ahuja Y, Ma Khin Pyi S, Malihi M, et al. Clinical results of ab interno trabeculotomy using the trabectome for open-angle glaucoma: the mayo clinic series in Rochester, Minnesota. Am J Ophthalmol 2013;156(5):927–935.e2. DOI: 10.1016/j.ajo.2013.06.001.
  35. Jea SY, Francis BA, Vakili G, et al. Ab interno trabeculectomy versus trabeculectomy for open-angle glaucoma. Ophthalmology 2012;119(1):36–42. DOI: 10.1016/j.ophtha.2011.06.046.
  36. Fontana L, De Maria M, Caristia A, et al. Comparison of gonioscopy-assisted transluminal trabeculotomy versus trabeculectomy with mitomycin C in patients with open-angle glaucoma. J Glaucoma 2021;30(1):101–108. DOI: 10.1097/IJG.0000000000001696.
  37. Grover DS, Smith O, Fellman RL, et al. Gonioscopy-assisted transluminal trabeculotomy: an ab interno circumferential trabeculotomy: 24 months follow-up. J Glaucoma 2018;27(5):393–401. DOI: 10.1097/IJG.0000000000000956.
  38. Bektas C, Aktas Z, Ucgul AY, et al. Prognostic factors affecting the surgical success of gonioscopy-assisted transluminal trabeculotomy. Indian J Ophthalmol 2021;69(6):1425–1429. DOI: 10.4103/ijo.IJO_2035_20.
  39. Matsuo M, Inomata Y, Kozuki N, et al. Characterization of peripheral anterior synechiae formation after microhook ab-interno trabeculotomy using a 360-degree gonio-camera. Clin Ophthalmol 2021;15:1629–1638. DOI: 10.2147/OPTH.S306834.
  40. Amari Y, Hamanaka T, Futa R. Pathologic investigation failure of trabeculotomy. J Glaucoma 2015;24(4):316–322. DOI: 10.1097/IJG.0b013e31829e1d6e.
  41. Aktas Z, Bektas C, Hasanreisoglu M. Panscleritis as an unusual complication of gonioscopy-assisted transluminal trabeculotomy. J Glaucoma 2019;28(2):e21–e23. DOI: 10.1097/IJG.0000000000001100.
  42. Hann CR, Bentley MD, Vercnocke A, et al. Imaging the aqueous humor outflow pathway in human eyes by three-dimensional micro-computed tomography (3D micro-CT). Exp Eye Res 2011;92(2):104–111. DOI: 10.1016/j.exer.2010.12.010.
  43. Fellman RL, Feuer WJ, Grover DS. Episcleral venous fluid wave correlates with trabectome outcomes: Intraoperative evaluation of the trabecular outflow pathway. Ophthalmology 2015;122(12):2385–2391.e1. DOI: 10.1016/j.ophtha.2015.08.038.
  44. 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):1037–1050. DOI: 10.1080/14728222.2017.1386174.
  45. Ethier CR, Li G, Lee C, et al. Netarsudil (NT) restores trabecular meshwork (TM) function/stiffness and reduces IOP in steroid-induced ocular hypertension (OHT). Invest Ophthalmol Vis Sci 2020;10(61):2325–2325.
  46. Li G, Lee C, Read AT, et al. Anti-fibrotic activity of a rho-kinase inhibitor restores outflow function and intraocular pressure homeostasis Barton M, Smith L, McDowell C, et al., ed. eLife., vol. 10 2021. p. e60831.
  47. Qiu TG. Trabodenoson on trabecular meshwork rejuvenation: a comprehensive review of clinical data. Expert Opin Investig Drugs 2021;30(3):227–236. DOI: 10.1080/13543784.2021.1873276.
  48. Hoy SM. Latanoprostene bunod ophthalmic solution 0.024%: a review in open-angle glaucoma and ocular hypertension. Drugs 2018;78(7):773–780. DOI: 10.1007/s40265-018-0914-6.
  49. Yun H, Zhou Y, Wills A, et al. Stem cells in the trabecular meshwork for regulating intraocular pressure. J Ocul Pharmacol Ther 2016;32(5):253–260. DOI: 10.1089/jop.2016.0005.
  50. Zhou Y, Xia X, Yang E, et al. Adipose-derived stem cells integrate into trabecular meshwork with glaucoma treatment potential. FASEB J 2020;34(5):7160–7177. DOI: 10.1096/fj.201902326R.
  51. Yun H, Wang Y, Zhou Y, et al. Human stem cells home to and repair laser-damaged trabecular meshwork in a mouse model. Commun Biol 2018;1(1):216. DOI: 10.1038/s42003-018-0227-z.
  52. Kumar A, Cheng T, Song W, et al. Two-step induction of trabecular meshwork cells from induced pluripotent stem cells for glaucoma. Biochem Biophys Res Commun 2020;529(2):411–417. DOI: 10.1016/j.bbrc.2020.05.225.
  53. Vingolo EM, Chabib A, Anselmucci F. Regeneration of trabecular meshwork in primary open angle glaucoma by stem cell therapy: a new treatment approach. Transpl Res Risk Manag 2019;11:11–16. DOI: 10.2147/TRRM.S160229.
  54. Kazerounian S, Zimbelmann M, Lörtscher M, et al. Canaloplasty ab interno (AbiC) - 2-year-results of a novel minimally invasive glaucoma surgery (MIGS) technique. Klin Monbl Augenheilkd 2020. Epub ahead of print.
  55. Hughes T, Traynor M. Clinical results of ab interno canaloplasty in patients with open-angle glaucoma. Clin Ophthalmol 2020;14:3641–3650. DOI: 10.2147/OPTH.S275087.
  56. Dickerson JE, Brown RH. Circumferential canal surgery: a brief history. Curr Opin Ophthalmol 2020;31(2):139–146. DOI: 10.1097/ICU.0000000000000639.
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