Transcript The early hypotony protection effect of intraoperative

The early hypotony protection effect of intraoperative
injection of viscoelastc material in trabeculectomy
DW.Lee, NC Cho, MJ Kim, EY Kwen
Department of Ophthalmology, Chonbuk National
University Medical School, Korea
Purpose
• Despite fewer complication of alternative procedure for
glaucoma like deep sclerectomy & argon laser suture lysis,
viscocanalostomy,
trabeculectomy has been gold standard surgical procedure for
glaucoma because of it’s broad indication & supporting
effectiveness.
• The viscoelastic substance whould help maintain the anterior
chamber, prevent hypotony, reduce hyphema and delay
filtering bleb scarring after trabeculectomy.
• But, there also has been some reports showing not much
difference when not using viscoelastics.
• We evaluated the effects of viscoelastic substance on
prevention of early postoperative hypotony after
trabeculectomy.
Method
• We prospectively evaluated 40 eyes of 38 patients who
underwent trabeculectomy by 1 surgeon from January 2005 to
August 2007.
• They were randomized into two groups.(group A and B).
• Standard trabeculectomy with 0.3% Mitomycin C was done
under retrobulbar anesthesia.
Method
• In group A of 23 eyes was used about 0.1ml of Viscoat®(Alcon,
U.S.A.) to reform the anterior chamber after conjunctival suture.
•
In the other group B of 17 eyes was used only balanced salt
solution(BSS) for anterior chamber reformation at the
completion of the procedure.
• We compared intraocular pressure & early complications for
postoperative 1 week between the 2 groups.
• Student’s t-test was used for visual acuity and IOP, chisquared
test was used for the evaluation of the complications.
Results
• The mean age of the patients was 51.8±18.9, 58.1±11.4 in
group A and B. The causing diseases were open angle
glaucoma 34%, 19%, angle closure glaucoma 21%, 24%,
neovascular glaucoma 17%, 29%, and others 26%, 29%
respectively in group A and B.
• The mean intraocular pressure(mmHg) was 35.9, 38.1 (p>0.01)
preoperatively, 14.7, 10.7 (p>0.01) at postoperative 1 day, and
12.4, 11.3 (p>0.01) at posterative 1 week, respectively in
group A and B.
• Postoperative shallow anterior chamber in 1 eye of group A
and 2 eyes of group B, hyphema in 1 eye of group A and 2
eyes of group B and choroidal detachment in 2 eyes of group
B. There were no statistical different incidences between the
two groups(p>0.01).
• Postoperative IOP rise over 30mmHg developed in 2 eyes of
group A. There were no statistical different
incidences between the two groups(p>0.01).
Results
Characteristics
Group A
Group B
23
17
Mean age
51.8
58.1
Preoperative intraocular
pressure
35.9
38.1
Primary open angle
8
3
Chronic angle closure
5
4
Neovascular glaucoma
4
5
Pseudoexfoliative
3
1
Uveitis
1
2
Angle recession & trauma
2
2
Eyes
Type of Glaucoma
Results
Mean intraocular pressure (mmHg)
Group 1
Group 2
P-value
Preoperative
35.9
38.1
P>0.01
Postoperative
1day
14.7
10.7
P<0.01
Postoperative
2day
12.3
10.9
P>0.01
Postoperative
7day
12.4
11.3
P>0.01
Results
Complications
Group 1
Group 2
P-value
Hypotony or
shallow anterior
chamber
1(4%)
2(12%)
P>0.01
Choroidal
detachment
0
1(6%)
P>0.01
Early intraocular
pressure peak
2(8%)
0
P>0.01
hyphema
1(4%)
2(12%)
P>0.01
Conclusion
• Viscoat®(Alcon, U.S.A.) was composed of 3% sodium
hyaluronate & 4% sodium chondroitin sulfate.
• Sodium chodroitin sulfate is viscoelastic biopolymer &
removed from anterior chamber after 24~30 hours, unlike
sodium hyaluronate that was metabolized.
• Viscoat injection after trabeculectomy has been believed that
has protective effect for early hypotony since Blondeau
reported, fewer early hypotony and anterior chamber
shallowing after using viscoat, which were responsible for
better visual acuity.
• And it also reported that viscoat injection did not ensure more
favorable outcomes or decreased incidence of complications.
Conclusion
• In our survey, injecting some viscoelastic substance into the
anterior chamber may help prevent postoperative hypotony &
complication to some degree, but statistically significant difference
was not demonstrated by between two–group comparison.
• This might be substituted by other safer procedures such as more
tighter closure of scleral flap with argon laser suture lysis or
releasable sutures.