Effectiveness and safety of combined cataract surgery and microhook ab interno trabeculotomy in Japanese eyes with glaucoma: report of an initial case series

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To report the early postoperative results and safety profile of ab interno microhook trabeculotomy (μLOT) combined with cataract surgery.

Patients and methods

This retrospective observational case series included 68 consecutive glaucomatous eyes of 23 Japanese men and 25 Japanese women [mean (SD) age, 76.0 ± 8.5 years] who underwent μLOT for intraocular pressure (IOP) and visually relevant cataracts. The LOT site/extent, perioperative complications, and complication treatments were collected from the medical and surgical records. The preoperative and postoperative IOP, numbers of antiglaucoma medications, logarithm of the minimum angle of resolution visual acuity (VA), anterior chamber (AC) flare, and corneal endothelial cell density (CECD) were compared.


After small incisional cataract surgery, the trabecular meshwork was incised in the nasal (6 eyes, 3.6 ± 0.5 clock hours), temporal (6 eyes, 3.8 ± 0.8 clock hours), or both nasal and temporal (56 eyes, 6.5 ± 0.6 clock hours) angles. The mean preoperative IOP (16.4 ± 2.9 mmHg) and number of antiglaucoma medications (2.4 ± 1.2) decreased significantly (P < 0.0001 and P = 0.0039, respectively) to 11.8 ± 4.5 and 2.1 ± 1.0 mmHg at 9.5 months postoperatively. Compared with the preoperative conditions, the final VA improved (P = 0.0002), the AC flare increased by 6.3 pc/ms (P = 0.0157), and the CECD decreased by 6% (P = 0.0005). Hyphema with niveau formation (28 eyes, 41%) and hyphema washout (6 eyes, 9%) were the most common postoperative complication and intervention, respectively. At the final visit, 54 eyes (79%) had achieved successful IOP control of 15 mmHg or less and IOP reduction of 15% or greater.


Combined μLOT and cataract surgery improves IOP and VA during the early postoperative period in patients with glaucoma and cataract.

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  1. 1.

    Chihara E, Nishida A, Kodo M, Yoshimura N, Matsumura M, Yamamoto M, et al. Trabeculotomy ab externo: an alternative treatment in adult patients with primary open-angle glaucoma. Ophthalmic Surg. 1993;24:735–9.

  2. 2.

    Tanihara H, Negi A, Akimoto M, Terauchi H, Okudaira A, Kozaki J, et al. Surgical effects of trabeculotomy ab externo on adult eyes with primary open angle glaucoma and pseudoexfoliation syndrome. Arch Ophthalmol. 1993;111:1653–61.

  3. 3.

    Tanito M, Ohira A, Chihara E. Surgical outcome of combined trabeculotomy and cataract surgery. J Glaucoma. 2001;10:302–8.

  4. 4.

    Tanito M, Ohira A, Chihara E. Factors leading to reduced intraocular pressure after combined trabeculotomy and cataract surgery. J Glaucoma. 2002;11:3–9.

  5. 5.

    Kashiwagi K, Kogure S, Mabuchi F, Chiba T, Yamamoto T, Kuwayama Y, et al. Change in visual acuity and associated risk factors after trabeculectomy with adjunctive mitomycin C. Acta Ophthalmol. 2016;94:e561–70.

  6. 6.

    Beck AD, Lynch MG. 360 degrees trabeculotomy for primary congenital glaucoma. Arch Ophthalmol. 1995;113:1200–2.

  7. 7.

    Chin S, Nitta T, Shinmei Y, Aoyagi M, Nitta A, Ohno S, et al. Reduction of intraocular pressure using a modified 360-degree suture trabeculotomy technique in primary and secondary open-angle glaucoma: a pilot study. J Glaucoma. 2012;21:401–7.

  8. 8.

    Dao JB, Sarkisian SR Jr, Freedman SF. Illuminated microcatheter-facilitated 360-degree trabeculotomy for refractory aphakic and juvenile open-angle glaucoma. J Glaucoma. 2014;23:449–54.

  9. 9.

    Grover DS, Godfrey DG, Smith O, Feuer WJ, Montes de Oca I, Fellman RL. Gonioscopy-assisted transluminal trabeculotomy, ab interno trabeculotomy: technique report and preliminary results. Ophthalmology. 2014;121:855–61.

  10. 10.

    Sato T, Hirata A, Mizoguchi T. Outcomes of 360 degrees suture trabeculotomy with deep sclerectomy combined with cataract surgery for primary open angle glaucoma and coexisting cataract. Clin Ophthalmol. 2014;8:1301–10.

  11. 11.

    Sato T, Hirata A, Mizoguchi T. Prospective, noncomparative, nonrandomized case study of short-term outcomes of 360 degrees suture trabeculotomy ab interno in patients with open-angle glaucoma. Clin Ophthalmol. 2015;9:63–8.

  12. 12.

    Tanito M, Sano I, Ikeda Y, Fujihara E. Microhook ab interno trabeculotomy, a novel minimally invasive glaucoma surgery, in eyes with open-angle glaucoma with scleral thinning. Acta Ophthalmol. 2016;94:e371–2.

  13. 13.

    Tanito M, Sano I, Ikeda Y, Fujihara E. Short-term results of micro-hook ab interno trabeculotomy, a novel minimally invasive glaucoma surgery in Japanese eyes: initial case series. Acta Ophthalmologica. 2017;. doi:10.1111/aos.13288.

  14. 14.

    Honjo M, Tanihara H, Inatani M, Honda Y, Ogino N, Ueno S, et al. Phacoemulsification, intraocular lens implantation, and trabeculotomy to treat pseudoexfoliation syndrome. J Cataract Refract Surg. 1998;24:781–6.

  15. 15.

    Tanihara H, Negi A, Akimoto M, Nagata M. Long-term results of non-filtering surgery for the treatment of primary angle-closure glaucoma. Graefes Arch Clin Exp Ophthalmol. 1995;233:563–7.

  16. 16.

    Chen PP, Lin SC, Junk AK, Radhakrishnan S, Singh K, Chen TC. The effect of phacoemulsification on intraocular pressure in glaucoma patients: a report by the American Academy of Ophthalmology. Ophthalmology. 2015;122:1294–307.

  17. 17.

    Kobayashi H, Kobayashi K. Randomized comparison of the intraocular pressure-lowering effect of phacoviscocanalostomy and phacotrabeculectomy. Ophthalmology. 2007;114:909–14.

  18. 18.

    Rosenquist R, Epstein D, Melamed S, Johnson M, Grant WM. Outflow resistance of enucleated human eyes at two different perfusion pressures and different extents of trabeculotomy. Curr Eye Res. 1989;8:1233–40.

  19. 19.

    Chihara E, Umemoto M, Tanito M. Preservation of corneal endothelium after pars plana tube insertion of the Ahmed glaucoma valve. Jpn J Ophthalmol. 2012;56:119–27.

  20. 20.

    Siriwardena D, Kotecha A, Minassian D, Dart JK, Khaw PT. Anterior chamber flare after trabeculectomy and after phacoemulsification. Br J Ophthalmol. 2000;84:1056–7.

  21. 21.

    Hayashi K, Manabe S, Yoshimura K, Kondo H. Corneal endothelial damage after cataract surgery in eyes with pseudoexfoliation syndrome. J Cataract Refract Surg. 2013;39:881–7.

  22. 22.

    Schumacher S, Nguyen NX, Kuchle M, Naumann GO. Quantification of aqueous flare after phacoemulsification with intraocular lens implantation in eyes with pseudoexfoliation syndrome. Arch Ophthalmol. 1999;117:733–5.

  23. 23.

    Ahmed IIK. MIGS and the FDA: what’s in a name? Ophthalmology. 2015;122:1737–9.

  24. 24.

    Kahook MY, Seibold LK, SooHoo JR, Mansouri K, Sharaawy T. A nuanced approach to the surgical management of glaucoma. Middle East Afr J Ophthalmol. 2015;22:1.

  25. 25.

    Minckler DS, Baerveldt G, Alfaro MR, Francis BA. Clinical results with the Trabectome for treatment of open-angle glaucoma. Ophthalmology. 2005;112:962–7.

  26. 26.

    Malvankar-Mehta MS, Chen YN, Iordanous Y, Wang WW, Costella J, Hutnik CM. iStent as a solo procedure for glaucoma patients: a systematic review and meta-analysis. PLoS ONE. 2015;10:e0128146.

  27. 27.

    Khaimi MA. Canaloplasty: a minimally invasive and maximally effective glaucoma treatment. J Ophthalmol. 2015;2015:485065.

  28. 28.

    Matlach J, Dhillon C, Hain J, Schlunck G, Grehn F, Klink T. Trabeculectomy versus canaloplasty (TVC study) in the treatment of patients with open-angle glaucoma: a prospective randomized clinical trial. Acta Ophthalmol. 2015;93:753–61.

  29. 29.

    Seibold LK, Soohoo JR, Ammar DA, Kahook MY. Preclinical investigation of ab interno trabeculectomy using a novel dual-blade device. Am J Ophthalmol. 2013;155:524–9.

  30. 30.

    SooHoo JR, Seibold LK, Kahook MY. Ab interno trabeculectomy in the adult patient. Middle East Afr J Ophthalmol. 2015;22:25–9.

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Author information

Correspondence to Masaki Tanito.

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Conflicts of interest

M. Tanito, Grants (Inami), Lecture fees (Aeon Astron, Alcon, HOYA, JFC, Kowa, MSD, NIDEK, Novartis, Otsuka, Pfizer, Santen, Senju, Zeiss), Supply of microhooks (Inami); Y. Ikeda, Grants (Inami), Lecture fees (Santen), Supply of microhooks (Inami); E. Fujihara, Grants (Inami), Lecture fees (Kowa, Novartis), Supply of microhooks (Inami).

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Video 1. Microhook ab interno trabeculotomy combined with cataract surgery in the left eye. (MP4 47006 kb)

Video 1. Microhook ab interno trabeculotomy combined with cataract surgery in the left eye. (MP4 47006 kb)

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Tanito, M., Ikeda, Y. & Fujihara, E. Effectiveness and safety of combined cataract surgery and microhook ab interno trabeculotomy in Japanese eyes with glaucoma: report of an initial case series. Jpn J Ophthalmol 61, 457–464 (2017).

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  • Microhook ab interno trabeculotomy
  • Minimally invasive glaucoma surgery
  • Intraocular pressure
  • Surgical complication
  • Cataract surgery