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Review
. 2019 Apr-Jun;9(2):67-71.
doi: 10.4103/tjo.tjo_38_19.

Ab-interno trabeculotomy-related glaucoma surgeries

Masaki Tanito  1 , Masato Matsuo  1
Affiliations
Review

Ab-interno trabeculotomy-related glaucoma surgeries

Masaki Tanito et al. Taiwan J Ophthalmol. 2019 Apr-Jun.

Abstract

Reductions of intraocular pressure during trabeculotomy result from relieving the resistance to aqueous flow by cleavage of the trabecular meshwork and inner walls of Schlemm's canal at the point of outflow resistance of the aqueous humor. Since trabeculotomy does not result in bleb formation, development of late-onset sight-threatening complications, such as hypotony maculopathy and endophthalmitis, that are associated occasionally with trabeculectomy develop less frequently after trabeculotomy. The ab-interno approach is used in several new procedures, including the Trabectome, Kahook Dual Blade, microhook abinterno trabeculotomy, and 360° suture trabeculotomy, instead of the ab-externo approach as in conventional trabeculotomy. These newly developed novel, minimally invasive, and trabeculotomy-related glaucoma surgeries can be good options for certain glaucoma cases, including early-stage open-angle glaucoma, developmental glaucoma, and glaucoma in elderly patients.

Keywords: Ab-externo trabeculotomy; Kahook Dual Blade; Trabectome; microhook ab-interno trabeculotomy; minimally invasive glaucoma surgery; suture ab-interno trabeculotomy.

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Conflict of interest statement

The microhooks used were codeveloped by Masaki Tanito, MD, PhD, and Inami and Co., Ltd. (Tokyo, Japan) and provided by Inami and Co., Ltd. Dr. Tanito receives royalties from Inami and Co., Ltd.

Figures

Figure 1
Figure 1
Various devices for novel trabeculotomy-related surgeries. (a) The Trabectome provided by Kowa Company Ltd. (http://www.kowa.co.jp). (b) The Kahook Dual Blade provided by JFC sale Plan (http://www.jfcsp.co.jp). (c) The Tanito ab interno Trabeculotomy Microhook provided by Inami and Co., Ltd. (http://inami.co.jp). (d) The Chin trabeculotomy suture provided by Handaya Co., Ltd. (http://www.handaya.co.jp)
Figure 2
Figure 2
Surgical procedure of microhook ab-interno trabeculotomy. (a) Observation of the anterior-chamber angle using a Swan-Jacob gonioprism lens shows the trabecular meshwork and that inner wall of Schlemm's canal is incised circumferentially using the tip of the microhook inserted into the anterior chamber through the small corneal incision. (b) A schematic drawing of the meshwork incision by the tip of the hook. This schema is provided by Inami Co. Ltd
Figure 3
Figure 3
Anterior-chamber angle findings after microhook ab-interno trabeculotomy. (a) Observation of the anterior-chamber angle using anterior-segment optical coherence tomography (Casia 2, Tomey). A trabeculotomy cleft is seen in both the temporal and nasal angles (arrows) postoperatively in the right eye. (b) Observation of the entire anterior-chamber angle using a 360° gonioscope (GS-1, Nidek).[21] Small but interrupted peripheral anterior synechiae (arrows) are seen postoperatively in the right eye
Figure 4
Figure 4
The typical extents of the incisions created in traditional ab-externo trabeculotomy and novel trabeculotomy-related glaucoma surgeries. (a) Conventional ab-externo trabeculotomy. (b) The Trabectome and Kahook Dual Blade. (c) Microhook ab-interno trabeculotomy. (d) Suture ab-interno trabeculotomy. The red arcs indicate the extent of the trabeculotomy, the blue lines the corneal side ports, and the blue box the scleral flap. These panels are adopted from our previous publication[20] with modification with the permission of the journal
See this image and copyright information in PMC

References

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