25-gauge vitrectomy needle speeds surgery
Pippa Wysong In Halifax, Nova Scotia
Sutureless 25-gauge vitrectomy is not only safe but significantly
reduces the time needed to do vitrectomy surgery, reported Marie-Jose
Fredette MD at the annual meeting of the Canadian Ophthalmological
Society in Halifax, Nova Scotia.
She presented findings from a prospective trial in which 30 eyes
of 30 patients underwent vitrectomy using the 25-gauge needle. She
compared those results to those of a control group of the same size
that was matched for diagnosis and severity, but underwent 20-gauge
vitrectomy surgery. Patients all had six-month follow-up evaluations.
Prior to surgery, visual acuity was similar between the 25- and
20-gauge patients at 6/21 and 6/24 respectively. IOP was similar
too, with an average of 13.5 mmHg. One day following surgery, IOP
averaged 9.2 mmHg in the 25-gauge group and 13.5 mmHg in the 20-gauge
group. Intraocular pressures were similar in both groups at the
six month follow-up, at 15 mmHg.
Five patients developed transient hypotony that resolved within
two weeks, and did not affect visual outcome. One case, however,
took 22 days to resolve.
The researchers also measured surgical time and how long the operating
room was needed. The mean duration of surgery for 25-gauge vitrectomy
was 25 minutes, compared to 38 minutes in the control group. The
operating room times for the two groups average 51 minutes and 66
"It represents about a 40% decrease in time of surgery, which
is about a 25% decrease in your operating room time."
The shorter time for surgery means more patients could be operated
on, helping relieve some of Canada's waiting lists for eye surgery,
"The study confirms that this new technology seems to have
advantages, but it comes with another set of complications,"
She explained that the complications aren't necessarily better or
worse than those seen with the 20-gauge needle, simply different.
One difference was an increased risk for hypotony with the 25-gauge
vitrectomy, while the 20-gauge needle was associated with a risk
of increased IOP.
However, patients who underwent a 25-gauge vitrectomy had less post-operative
pain because of the lack of sutures, and their eyes were not as
red as those whose surgery was done with the 20-gauge needle.
She commented that one disadvantage of the 25-gauge needle is that
because of its newness, there is a limited choice of additional
surgical and optical instruments that can be used with it. She expects
this will change as other technologies catch up.
Peter Kertes, MD from the Ottawa Eye Institute found the idea of
the shorter time for surgery with the 25-gauge needle appealing:
"In the Canadian setting especially, where the operating room
time is limited, if you can do more cases in a day you're that much
further ahead," he said
The 25-gauge needle has been available for only six months in Canada,
and is being used by only a few centres in the country. The 25-gauge
needle has a diameter of 0.5mm, almost half the size of the 20-gauge
needle. The incision is so small that sutures are not needed because
the wound heals on its own.
The study was useful because very few centres in Canada have the
instrumentation or equipment to use this approach. The experience
gives ophthalmologists an idea of what to expect from the new technology,
Centre Hospitalier Universitaire de Quebec
Peter Kertes MD
The Retina Society of the COS.