Transcript Slide 1

Comparison of postoperative intraocular pressures after
phacoemulsification with and without use if anti glaucoma drops
Riley Hall BScα, Robert Mitchell MD, FRCSCβ
University of Saskatchewanα, University of Calgaryβ
Authors have no financial interest
OBJECTIVES
To determine the intraocular pressure in the
immediate 4 hour period following cataract
surgery and establish whether the use of antiglaucoma drops applied at the end of surgery
influences it.
METHODS
A double blind study was performed at an ambulatory surgical center in Calgary, Alberta, Canada.
Prospective data was collected from patients scheduled for routine, microincisional cataract
surgery (MICS). All surgeries were uncomplicated. A soft, foldable intraocular lens was inserted
into the posterior chamber. Ocucoat viscoelastic (methacellulose) was carefully washed out at the
end of each procedure. Intraocular pressures were set at 20-30 mmHg using a Barraquer
tonometer at the end of each case. After receiving prior informed consent, patients were randomly
selected into two groups. One group received a combination beta-blocker and carbonic anhydrase
inhibitor drop at the end of surgery. The other group received no anti-glaucoma therapy at the end
of surgery. The Intraocular pressures in the two groups were measured prior to surgery, at 1 and 4
hours post operatively, and the following day using an iCare tonometer TA011. This instrument
was selected as it is the least invasive and safest method to test pressure on newly operated eyes.
The intraocular pressures in the 2 groups were then compared.
RESULTS
Intraocular pressures were analyzed in 80 eyes of 71 patients, 39 received the anti-glaucoma drop
and 41 did not. The treated eyes had an average intraocular pressure at 1 hour of 13.95mmHg
(SD=7.97mmHg, 4.12% decrease from preop). At 4 hours it was 15.09mmHg (SD=5.91mmHg,
3.58% increase from preop), and the following day it was 12.02mmHg (SD=4.96mmHg, 17.39%
decrease from preop). The untreated eyes had an average intraocular pressure at 1 hour of
23.17mmHg (SD=10.11mmHg, 35.09% increase from preop). At 4 hours it was 25.33mmHg
(SD=8.93mmHg, 40.62% increase from preop) and the following day it was 17.82mmHg
(SD=4.41mmHg, 18.48% increase from preop). Patients with intraocular pressure greater than
35mmHg at any point during the study were treated but remained in the study. There were 8 such
cases (7 from the untreated group; 1 from the treated group).
Summary of intraocular pressures at 1 hour, 4 hours, and the following day.
Group
Treated
Untreated
Difference
Preop IOP
14.4 (+/-4.6)
15.0 (+/-3.8)
0.6 (p=0.503)
(Pressures in
mmHg)
Treated
Untreated
1 hr IOP
14.2 (+/-8.7)
23.17 (+/-10.1)
8.97 (p<0.0001)
% Change from
Preop
-1.4%
+54.5%
4 hr IOP
15.1 (+/-5.9)
25.2 (+/-8.8)
10.1 (p<0.001)
% Change from
Preop
+4.9%
+68.0%
Next day IOP
12.1 (+/-4.9)
17.1 (+/-5.2)
5.0 (p<0.0001)
% Change
from Preop
-16.0%
+14.0%
IOP's
30.0
Average IOP (mmHg)
25.0
20.0
15.0
`
10.0
5.0
0.0
0
1
2
Time
3
4
Age ,
Tre ate d(T)
Ge nder Untre ate d(U)
73 F
U
51 M
U
89 M
U
72 F
U
85 F
U
72 F
U
72 F
U
53M
U
77 F
U
72 F
U
72 F
U
65 F
T
83 F
T
69 F
T
Type of
Pre op
C omplication IOP
Elevated IOP
21
Elevated IOP
21
Elevated IOP
15
Elevated IOP
18
Elevated IOP
20
Elevated IOP
21
Elevated IOP
14
Elevated IOP
20
Elevated IOP
16
Elevated IOP
19
Elevated IOP
17
Elevated IOP
23
Corneal
-Abrasion
Anterior
-Chamber
Leak
1hr
IOP
40
37
34
24
45
38
20
37
34
33
16
40
--
4hr
IOP
-21
39
35
--36
-43
44
36
---
24hr
IOP
19
-10
11
9
18
11
21
21
-14
---
--
--
15
DISCUSSION
Many patients experience an intraocular pressure spike following cataract surgery. Intraocular
pressure can be greater than 30mm Hg when measured the same day as surgery.1 Kir, Lakmak,
and Dyanir determined that 1 drop of brinzolamide (carbonic anhydrase inhibitor) 1% following
clear corneal phacoemulsification surgery is sufficient to control intraocular pressure rise within
the first 4 to 6 hours following surgery.2 In our study, 10 out of 80 (12.5%) operated eyes
developed a complication following surgery requiring immediate treatment. These complications
included 8 cases of intraocular pressure spikes greater than 35mmHg, a wound leak, and a
corneal abrasion.
CONCLUSIONS
Based on the results of our study we believe that all patients would benefit from receiving an antiglaucoma drop at the end of cataract surgery. This would eliminate the often significant spike in
intraocular pressure that may occur in the 4 hour period following cataract surgery. Additionally,
examination of the eye in the early postoperative period may reveal complications that would
otherwise go unnoticed.
REFERENCES
Tranos, PG et al. Same-day versus first day review of intraocular pressure after uneventful
phacoemulsification. J Cataract Refract Surg. 2003; 29:508-512
Kir, E, Lakmak, H, Dyanir, V. Medical control of intraocular pressure with brinzolamide 1% after
phacoemulsification. Can J Ophthalmol. 2008; vol. 43 no. 5.