Abstract
Purpose :
Gonioscopy-assisted transluminal trabeculotomy (GATT), or suture trabeculotomy ab interno (SLOT), are micro-invasive glaucoma surgery (MIGS) procedures which incise the trabecular meshwork (TM) using an illuminated catheter or suture. Both procedures were designed to cut the whole TM (360 degrees), however, it is still controversial as to whether or not the intraocular pressure (IOP) reduction correlates to the incision amount. In this retrospective study, we evaluated the influence of incision arc amount of TM, and other factors, on the short-term outcome of modified GATT/SLOT procedures.
Methods :
This study involved 79 eyes of Japanese glaucoma patients (age range: 28-92 years). Inclusion criteria were those who underwent modified GATT/SLOT at the university hospital of Kyoto Prefectural University of Medicine, Kyoto, Japan between March 2016 and September 2017, and who were followed up for more than 2-months postoperative. Briefly, the surgical procedures of modified GATT/SLOT were as follows. Under the double-mirror goniolens guide, an initial small goniotomy was performed and a 5-0 nylon suture with a rounded edge was continuously inserted into the Schlemm’s canal until the end stacked. Then, another goniotomy was performed at the tip, and the suture was pulled into the anterior chamber, cutting the TM from the insertion point to the end. The incision arc amount was then calculated from the recorded operation video. The clinical features of age, sex, glaucoma type, coexistent phaco surgery, pre and postoperative IOP, anti-glaucoma drug use were also recorded. Among each variable, stepwise multiple regression analysis with the forward selection method and the Cox proportion hazard test were performed.
Results :
Patient demographics are shown in Table 1. Stepwise multiple regression analysis showed that pre-IOP was the only statistically significant determinant of IOP decrease at 3-months post surgery (p=0.001). The Cox proportion hazard test showed that pre-IOP was the only significant explanatory variable for the success rate of modified GATT/SLOT (hazard ratio 1.098, p=0.027, [1.011-1.193]).
Conclusions :
The short-term outcomes of the modified GATT/SLOT procedures were statistically influenced by pre-IOP and not by incision arc amount.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.