Abstract
Purpose :
To investigate variability of diameter of commercially available 3-0 Nylon suture materials commonly employed as intraluminal stents with the Baerveldt Glaucoma implant (BGI). The BGI has a nominal inner diameter of 300 um. Nominal USP diameter for 3-0 monofilament suture is 200-249 um. Previously (ARVO 2017), the authors demonstrated that a stent of 240-250 um is necessary to reduce flow through the BGI to levels approaching the physiologic aqueous outflow value of 2.75 uL/min. (Brubaker 1991).
Methods :
Samples of 3-0 Nylon suture material from five manufacturers (1-3 separate lots per manufacturer) were studied. Diameters were measured at 10 equally spaced points along the length of each sample using a digital micrometer (Mitutoyo Model IP65, 1 um accuracy), by two examiners in a masked fashion.
Results :
In the Table, Lines 3 and 4, units are um. Line 5 gives p-Value for diameter vs. median (Manufacturer 3), by Student’s T Test. All lots and measurements for each manufacturer have been pooled.
Conclusions :
Samples within each manufacturer were highly consistent, and all diameters met the USP standard. Only samples from 2 of 5 manufacturers, however, were of sufficient diameter to significantly affect outflow. Depending on manufacturer, commercially available 3-0 Nylon has variable diameter; when it is used as a stent with BGI, resultant aqueous outflow may therefore be unpredictable.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.