Abstract
Purpose :
To evaluate incisional or excisional tissue-level effects of ab interno goniotomy techniques on human trabecular meshwork (TM).
Methods :
The TM from human cadaveric corneal rim tissue was treated using 4 techniques: (1) microvitreoretinal (MVR) blade; (2) TrabEx (Microsurgical Technology, Redmond, WA); (3) Gonioscopy-assisted transluminal trabeculotomy (GATT) with 5-0 prolene suture; (4) Kahook Dual Blade (KDB) Glide device (New World Medical, Rancho Cucamonga, CA). A single human corneal rim was used for each device with at least 180 degrees of treated TM in each case. Four random sections were then selected for analysis and comparison between devices. Tissue samples underwent standard histologic processing with H&E stain followed by comparative analyses.
Results :
The MVR blade created an incision of the TM without removal of tissue. The incision also extended into the scleral wall in all treated areas. The TrabEx device removed a variable portion of TM with large leaflet tissue remnants (range of 100-200µm in total length) in all treated areas. GATT with 5-0 prolene suture resulted in incision of the TM proximate to Schwalbe’s line with no excised tissue evident in treated areas. Areas treated with the KDB Glide device resulted in nearly complete excision of TM overlying the canal of Schlemm (leaflet remnants ranged from 0 to 50µm in length) without injury to surrounding tissues.
Conclusions :
The various methods used for performing ab interno goniotomy resulted in varying degrees of incision or excision of TM. Only the KDB Glide device resulted in reliable excision of TM with the other devices producing incision or minimal excision of tissue. Incisional treatments to allow for aqueous humor bypass of TM may be more prone to fibrosis and closure compared to excisional treatments. Clinical correlation is required to better understand the implications of the current findings when using these methods to lower intraocular pressure in eyes with glaucoma.
This is a 2020 ARVO Annual Meeting abstract.