Study of The Effects of Various Intraocular Pressure
Reducing Drugs in Reducing Postoperative Rise in Intraocular Pressure after
Cataract Surgery
Bansal
Manish, Viswnadham K. K., Thakur
Amit K., Sanat Singh, P.K. Kar, Khan Q.H., Shrivastav P.K.
Govt. Medical College, Jagdalpur (CG)Bastar.
ABSTRACT:
Methods: This post operative randomized double
masked clinical trial comprised patients with age related cataract having
undergone extracellular cataract extraction (ECCE) with or without posterior chamber
Intra ocular lense implementation (PC-IOL).They were
randomly assigned to use topical timoilol or betaxolol or levobunalol or acetazolamide or intracameral pilocarpine (Group 1a/1b/1c/1d/.1e) respectively at the
completion of the surgery. Two controls were taken- a.Intra-ocular pressure in the
follow eye (Control-I) b.
Intraocular pressure in the operated eye ,in which no Introcular
pressure reducing drugs had been instilled (Control-II ) (Group-II).
Intra-ocular pressure (IOP) was measured 6 hours, 24hours,3rd day,7th
day and 2nd month postoperatively. The anterior chamber was examined
for the levels of cells and flare using slit lamp examination.
Results :Levobunalol was more effective in reducing post
operative IOP rise at 6 hours of surgery ,3rd day ,7th
day 1st month, and 2nd month where as Timolol
was more effective at 24 hours. There were significant difference in IOP
between Group –I (those patients who received topical iop
reducing drugs )and group –II (operated patients without any IOP reducing drugs
)post operatively ( p<0.05).No excessive postoperative inflammation was
observed in any group. In the control group –I (fellow eye), IOP remained
constant throughout the period. This indicated that the drugs were not playing
any major role in altering IOP of the fellow eye. In the control II (group
–II), maximum mean pressure rise was 18 mm Hg at six hours .This indicated that
it was the operative procedure that was causing the rise in IOP .Diurnal
variation in IOP was playing no significant role.
KEYWORDS: Cataract, Intraocular pressure
INTRODUCTION:
Cataract surgery has been associated with post
operative intra ocular pressure elevation .It is a well documented phenomenon
that IOP reaches its highest between 6 and 8 hours after cataract extraction.
This rise in IOP may lead the complications like Ischaemic
optic neuropathy, corneal oedema ,deterioration of
visual fields in glaucomatous eye ,retinal vascular occlusion and inhibition of
wound healing. Keeping in mind the above facts and in 1957 a study group of
World Health Organization (W.H.O.) has expressed the view that in order to get
a comprehensive picture of the disease (health problem) ,more and more studies
have to be carried out(1). This prompted the authors to under
take this study was to evaluate the effects of IOP reducing drugs
instilled preoperatively, on the pattern of IOP changes after cataract surgery
,to compare the efficacy of these drugs in controlling early postoperative rise
of IOP and to observe the pattern of IOP changes in the contralateral
eye (Phakic, Pseudophakic, Aphakic) following cataract surgery.
MATERIALS
AND METHODS:
This post operative randomized double masked clinical
trial study comprised patients with age related cataract having undergone
extracellular cataract extraction (ECCE) with or without posterior chamber
Intra ocular lense implementation (PC-IOL).They were
randomly assigned to use topical timoilol or betaxolol or levobunalol or acetazolamide or intracameral pilocarpine (Group 1a/1b/1c/1d/.1e) respectively at the
completion of the surgery .Two controls were taken-
a.Intra-ocular pressure in the follow eye (Control-I)
b. Intraocular
pressure in the operated eye, in which no Introcular
pressure reducing drugs had been instilled (Control-II ) (Group-II)
c.Group- I as patients who had been given timoilol
or betaxolol or levobunalol
or acetazolamide or intracameral
pilocarpine at the completion of the surgery in the
operated eye.
Intra-ocular pressure (IOP) was measured 6 hours,
24hours, 3rd day, 7th day and 2nd month postoperatively. The
anterior chamber was examined for the levels of cells and flare using slit lamp
examination.
A total of 105 patients were included in this study.
There were 20 patients each in the topical timoilol
or betaxolol or levobunalol
or topical acetazolamide. There were 25 patients in intracameral pilocarpine group.
Proper history taking including chiefs complaints, history of present illness,
negative history, past history, family history, and personal history of each
patients were recorded in a predawn proforma. The
patients were examined preoperatively and then after 5-7 hours, 1 day,3 days, 7
days, 1 month, and 2-4 months postoperatively. The examination included visual
acuity after full refractive correction ,torch light examination ,slit lamp
examination, macular function test ,fundus
examination ,and IOP measurement by both application and schitoz
tonometry.IOP pattern was observed in each group ,inter group comparisons were
made and results were derived to draw conclusions. Mean (Average) ± 1S.D.
(Standard Deviation), Student’s t-test the chi –square test were used to test
the statically significance of differences in IOP between the different groups
when appropriate.
OBSERVATIONS AND DISCUSSIONS:
Average age of patients in the study was 59 years
(range between 38 to 75 years). Majority of the patients (33.3%) were in the
age group of 51 to 60 years. Out of total 105 patients in the study, 54 (51.1%)
females and 51(48.9%) were males. Out of total cataract surgeries conducted, 57
(54.0%) were extra capsular cataract extractions without PC-IOL implantation
and 48 (46.0%) extra capsular extractions with PC-IOL implantation. The
selected drugs were instilled at the end of surgery and following observations
were recorded :-
Timolol Group-
After 6-8 hours, 1st, 3rd and 7th
day postoperatively the mean IOP was significantly lower in the Timolol group in comparison to control group –II and the
decrease was statically significant (p < 0.05 ).The mean IOP was still lower
after 1 month and 2-4 months postoperatively as compared to the control group
,but it was not statically significant (p>0.05). The maximum decrease in
IOP after surgery in Tiomolol
group was 3.50± 0.17 mm Hg at 24 hours after surgery. The average increase in
IOP reached in control group –II was 4.00 mm Hg. The mean pressure in the
fellow eye (control –I)remained steady (14.20 mm Hg) throughout the study
period.
Betaxolol Group: 24 hours postoperatively the mean IOP was 11.70
± 2.28 mm Hg in this group which was significant as compared to the
preoperative IOP of 14.30 ±2.03 mmHg .At 1 month and 2 month after surgery,
there was no significant difference in IOP in Betaoxolol
and control group-II.The mean pressure in the
following eye (Control-I) remained steady 12.30 mm Hg throughout study period.
The average maximum IOP reached in control –II was 18.00 ± 3.02 mm Hg at 24
hours after cataract surgery.
Levobunalol Group: After 6-8 hours ,1st ,3rd
,7th day postoperatively the mean IOP was significantly lower in the
Levobunalol group than in the control group –II and
the decrease was statically significant (p<0.05).The mean IOP was still
lower after 1month and 2-4 months postoperatively in the Levobunalol
group as compared to the control group–II, which was statistically
insignificant(p>0.05). The average (mean) of the maximum rise of IOP after
surgery was 4.0 mmHg .The average (mean)of the maximum decrease in IOP was 3.20
±0.45 mmHg.
Topical Acetazolamide Group:
In this treated group at 6-8 hours, 24 hours, 3rd day, 7th day postoperatively
statistically significant decrease in IOP compared to control group –II. Mean
IOP WAS 11.00 ± 2.32 mm Hg ,11.00 = 2.30 mmHg ,11.40 =2.16 mmHg and 12.00 =
2.10 mmHg at 6-8 hours ,1st day ,3rd day and 7th
day respectively in the topical acetazolamide group
compared to its preoperative IOP of 13.60 ± 2.48 mm Hg .The mean pressure in
the fellow eye (control-I)remained steady 13.60 mm Hg throughout type study
period. The average (mean) of the maximum decrease IOP after surgery in this
group was 2.60 ± 0.18 mm Hg.
Intra cameral Pilocarpine
group : The lowest IOP value in this group was at 6-8 hours ,was 10.50 ±3.06 mm
Hg as compared to its preoperative value of 12.20 ±2.76 mm Hg .At the same time
the mean IOP of the control Group-II was 18.00 ±2.80 mmHg as compared to
preoperative IOP of 14.00 ± 1.41 mm Hg. twenty four hours and 3rd
day postoperatively ,the mean IOP of the pilocarpine
group was 11.00 ±3.40 mm Hg and 11.40 ± 2.68 mm Hg respectively ,while that in
the control group –II was 18.00 ±3.02 mm Hg and 16 .00 ±2.64 mm Hg
respectively. These difference were statistically significant .The mean
pressure in the fellow eye (control-I) remained steady 12.80 mm Hg through the
study period.
Comparison (2) of various IOP reducing drugs
:
a. In the first six hours after surgery ,most
reduction in post operative IOP was maintained in topical Levobunalol
group (22.60 %) followed by Timolol (22.0 %), Acetazolamide (19.0%), Betaxolol
(16.0%) and Pilocarpine group (13.9%).
b. In the first 24 hours after surgery, most
reduction in post operative IOP was
maintained in topical Timolol group (26%) followed by
Levobunalol (23 %), Acetazolamide
(19 %) Betaxolol (18%) and Pilocarpine
group (13.9%).
c. In the 3rd day after surgery,
most reduction in post operative IOP was maintained in topical Levobunalol group (20.5 %) followed by Timolol
(18.5%), Betaxolol (16.70%) Acetazolamide
(16 %) and Pilocarpine group (6.5%).
d. In the 7th day after surgery,
most reduction in post operative IOP was maintained in topical Levobunalol group (20.50%) followed by Betaxolol
(13.2%) ,Acetazolamide (11.7%), Pilocarpine
(9.8%) and Timolol
(6 %).
e. In the first month after surgery, most
reduction in post operative IOP was maintained in topical Levobunalol
group (15.60%) followed by Betaxolol (11.8%), Pilocarpine (8%),Timolol (1.5%)
and Acetazolamide group (0.7%).
f. In the 2nd month after surgery,
most reduction in post operative IOP was maintained in Levobunalol
group (6.9%) followed by Timolol (3.70%), Pilocarpine (2.5%), Betaxolol
(2%) and acetazolamide group.
CONCLUSIONS:
From above observations and discussion the
authors reached to the conclusion that in the present study Levobunalol
in a concentration of 0.5 %instilled preoperatively just after cataract surgery
is more effective in reducing postoperative IOP rise following cataract surgery
than any other drugs and is also most effective in dealing with the
complications arising from raised IOP.
There is so many prejudices in the community
about Cataract surgery .All these can be removed by proper and scientific
impartation of knowledge in the community through the various mass medias (3)
like Television, Radio, local traditional media’s like folk dances and folk
songs.
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for M.S. (Ophthalmology) 2001 submitted to AMU, Aligarh (UP)
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A.K.: Management of information system in context of health care delivery; J. Ravishankar University :Vol.14 ,No-B(Science )2001; pp35-40
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Received on 05.06.2011
Modified on 16.01.2012
Accepted on 15.02.2012
© A&V Publication all right reserved
Research J. Pharmacology and Pharmacodynamics.
4(2): March - April, 2012, 116-118