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Comparison of 12-month surgical outcomes of ab interno trabeculotomy with phacoemulsification between spatula-shaped and dual-blade microhooks



To compare 12-month clinical results of spatula-shaped and dual-blade microhooks ab interno trabeculotomy with phacoemulsification.

Study design

Retrospective comparative study.


We conducted a retrospective chart review of Japanese open-angle glaucoma patients who underwent ab interno trabeculotomy with phacoemulsification with a 12-month follow-up. Two types of trabecular hook were used: the spatula-shaped Tanito Trabeculotomy ab interno Micro-hook® and the Kahook Dual Blade®. Changes in intraocular pressure (IOP) and medication scores comprised the main outcome metrics. We also analyzed and compared patient demographics and the occurrence of complications.


Trabeculotomy was performed using a spatula-shaped hook in 17 eyes and a dual-blade hook in 15 eyes. Significant reductions in IOP (p < 0.001) and medication scores (p < 0.001) were noted in both groups after the 1-month time point. The percentage changes of IOP from baseline at each time point were not significantly different between groups, though there was a significant difference in medication scores at 12 months (p = 0.0192). Postoperative complications occurred similarly in both groups; one case in the dual-blade group required additional filtration surgery.


Ab interno trabeculotomy with phacoemulsification was effective in lowering IOP both with spatula-shaped and with double-blade microhooks. At 12 months more medications were used postoperatively in the spatula-shaped microhook group; however, the reductions in the medication scores from baseline were statistically significant in both groups.

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Corresponding author

Correspondence to Takashi Fujishiro.

Ethics declarations

Conflicts of interest

T. Omoto, None; T. Fujishiro, None; K. A. Shimizu, None; K. Sugimoto, None; R. Sakata, Financial support (TOMEY, Santen, Alcon, Senju, Nitten, Kowa); H. Murata, None; R. Asaoka, None; M. Honjo, None; M. Aihara, Financial support (Novartis, Pfizer, Kowa, Otsuka, Wakamoto, Nitten, Johnson & Johnson, Glaukos, TOMEY, Ono, Crewt Medical Systems, Sato, Santen, Senju, Alcon), Consultant fee (Pfizer, Kowa, Otsuka, Wakamoto, HOYA, InnFocus, Glaukos, IRIDEX, Crewt Medical Systems, Astellas, Santen, Senju, Alcon), Lecture fee, Non-financial support (Novartis, Pfizer, Kowa, Otsuka, Nitten, Johnson & Johnson, HOYA, Glaukos, TOMEY, IRIDEX, Crewt Medical Systems, Canon, Zeiss, Sato, Santen, Senju, Alcon).

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Corresponding Author: Takashi Fujishiro

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Omoto, T., Fujishiro, T., Asano-Shimizu, K. et al. Comparison of 12-month surgical outcomes of ab interno trabeculotomy with phacoemulsification between spatula-shaped and dual-blade microhooks. Jpn J Ophthalmol 65, 402–408 (2021).

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  • Trabeculotomy
  • Trabeculectomy
  • Glaucoma
  • Intraocular pressure
  • MIGS