Abstract
Purpose :
This study compared the traction forces produced in an ex-situ vitrectomy setting at flow-matched conditions between 25+ Ga HYPERVIT® Dual Blade vitrectomy probes operating at 20000 CPM and single blade 25+ Ga Advanced ULTRAVIT® vitrectomy probes operating at 10000 CPM.
Methods :
Testing was performed using bovine vitreous. Ten Alcon 25+ Ga HYPERVIT® beveled 20K CPM vitrectomy probes and Alcon 25+ Ga Advanced ULTRAVIT® beveled 10K CPM vitrectomy probes were used in flow-matched conditions. Vitreous flow testing was first performed on both types of probes to determine the vacuum levels that resulted in an equivalent flow rate when aspirating pure vitreous. Each probe was advanced towards the vitreous which was suspended in a chamber filled with BSS. The vitreous also was attached to a force sensor. The traction force, flow rate, probe position, and pressure signals were recorded. The data was analyzed to determine the force distribution as well as the mean force, peak force in each cut cycle, and maximum force. Statistical analysis was performed with P <0.05.
Results :
The flow testing identified the flow-normalizing vacuum settings during aspiration were 260 mmHg for the 25+Ga HYPERVIT® 20K probes and 340 mmHg for the 25+Ga Advanced ULTRAVIT® 10K probes.
When tested at the flow-normalizing aspiration levels, 25+ HYPERVIT® Dual Blade probes generated fewer high traction forces compared to 25+ Advanced ULTRAVIT® probes. After removing the low force regions (<0.5mN), for each percentile above the 66th percentile, the force was significantly lower for the HYPERVIT® compared to the Advanced ULTRAVIT® at the same percentile level (P<0.05). For example, the 90th, 95th, and 99th percentile forces were smaller by 12.8%, 14.4%, and 14.4%, respectively. Again, removing the low force regions, 25+ HYPERVIT® showed decreased average force, average peak force, and average maximum force during the whole process by 8.01%, 15.78%, and 12.22%, respectively, compared to 25+ Adv ULTRAVIT® probes (P<0.05).
Conclusions :
The study revealed that 25+Ga HYPERVIT® dual blade probes generated lower traction forces compared to 25+Ga Advanced ULTRAVIT® probes when removing vitreous at the same flow rate suggesting their potential advantage during vitrectomy with a lower likelihood of high traction force occurrence and reduced adverse events.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.