International Journal of Clinical Medicine, 2013, 4, 375-377 Published Online September 2013 ( 375
Impact of Ocular Compression on Ocular Surface
Bacterial Contamination
Amir Reza Daneshmand Eslami1*, Nikolai M. Sergienko1, Ivan P. Bilko2
1Department of Ophthalmology, National Medical Academy of Postgraduate Education, Kiev, Ukraine; 2Department of Microbiol-
ogy and Epidemiology, National Medical Academy of Postgraduate Education, Kiev, Ukraine.
Email: *
Received June 12th, 2013; revised July 16th, 2013; accepted August 5th, 2013
Copyright © 2013 Amir Reza Daneshmand Eslami et al. This is an open access article distributed under the Creative Commons At-
tribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is prop-
erly cited.
Background: To study the impact of preoperativ e ocular compression on bacterial contamination of the lid margin and
conjunctival sac. Methods: This study evaluated 106 eyes from 106 patients undergoing cataract surgery. Preopera-
tively, all of the patients received one drop of 0.5% levofloxacin eye drops 5 times per day for 4 days. The patients were
divided into 2 groups after receiving retrobulbar anaesthesia. The study group (75 eyes) received 15 ± 2 minutes of
ocular compression, and the control group (31 eyes) remained with their eyes closed for 15 ± 2 minutes without the ap-
plication of ocular compression or digital massage. Following the device removal (study group only) and the opening of
the eyes, bacterial cultures were taken from the lid margin and conjunctival sac. Results: The lid margin was positive
for bacteria in 23 eyes (30.7%) in the study group vs. 3 eyes (9.7%) in the control group (P = 0.0223), and the con junc-
tival sac was positive for bacteria in 16 eyes (21.3%) in the study group vs. 5 eyes (16.1%) in the control group (P =
0.5409). Conclusion: Preoperative ocular compression is associated with the release of meibomian gland secretions and
bacterial contamination of the eyelid edges.
Keywords: Bacteria; Conjunctival Sac; Endophthalmitis; Lid Margin; Ocular Compression
1. Introduction
Postoperative endophthalmitis (POE) remains a rare but
severe complication in modern cataract surgery [1]. The
most common sites of ocular bacterial contamination
leading to POE include the eyelids, skin and conjunctiva
[2,3]. The lid margins, which carry bacterial flora to the
skin surface, and meibomian gland secretions also play
an important role in POE development. However, it
remains unclear whether preoperative ocular compres-
sion (OC), which is performed to reduce intraocular pres-
sure (IOP), can promote bacterial contamination of the
eyelids and conjunctiva. Although in recent years OC has
become less popular, this technique is still commonly
performed. Pressure delivered via the modified Honan’s
balloon is realised not on ly on the eyeball but also on the
lid margin and may provoke the release of meibomian
gland secretions that contain bacteria.
The aim of this study was to determine the impact of
preoperative ocular compression on bacterial contamina-
tion in the lid margin and the conjunctival sac.
2. Materials and Methods
2.1. Study Sample
This study evaluated 106 eyes from 106 patients under-
going cataract surgery. The exclusion criteria included
systemic or local infection, con junctivitis, b lepharitis, da-
cryocystitis, meibomian gland dysfunction and diabetes
mellitus. Preoperatively, all of the patients received one
drop of 0.5% levofloxacin ophthalmic solution (Ofta-
quix®, Santen Oy, Niittyhaankatu 20, 33720 Tampere,
Finland) 5 times per day for 4 days.
The patients were placed in the supine position prior to
treatment and remained undisturbed throughout the test
period. Retrobulbar anaesthesia was administered with a
single injection of 0.5% bupivacaine hydrochloride, 2%
lidocaine hydrochloride, and 0.5% hyaluronidase (3.75
IU/ml). The volume of the block ranged from 3.5 to 5.5
ml, depending on the patient’s weight.
The patients were divided into two groups. The study
group (75 eyes of 75 patients) received retrobulbar
anaesthesia in addition to the preoperative application of
*Corresponding a uthor.
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Impact of Ocular Compression on Ocular Surface Bacterial Contaminat i on
OC (approximately 30 mm Hg) for 15 ± 2 minutes using
a modified Honan’s balloon, and the control group (31
eyes of 31 patients) received retrobulbar anaesthesia
without the preoperative application of OC or digital
massage. In the control group, the patients’ eyes re-
mained closed for 15 ± 2 minutes after the anaesthesia
administration. Approval for accessing the patient health
records was obtained from the local research ethics
committee. Informed consent was obtained from each
patient. The study protocol and the safety and efficacy of
the intervention s were explained to all of the participants
prior to their enrolment.
2.2. Bacteriological Investigation
After the specified period of 15 ± 2 minutes and follow-
ing the device removal (study group only), the eyes were
opened, and bacterial cultures from the conjunctival sac
and lid margin were immediately initiated using sterile
cotton swabs moistened with sterile saline solution. In
addition, swabbing was performed for the lower lid
margin by rolling the swab from the lateral canthus up to
the lacrimal point. The samples from each eye were
placed in separate tubes containing thioglycolate broth
and incubated at 37˚C for 24 h. The bacterial isolation
and identification were performed using standard me-
thods, as described elsewhere [4].
2.3. Statistical Analysis
The chi-squared test was used to compare the studied
variables. A P value less than 0.05 was considered statis-
tically significant.
3. Results
The results of this study are summarised in Tables 1 and
2 Coagulase-negative staphylococci were the most com-
monly cultured bacteria identified on both the lid margin
and the conjunctiva sac. In the study group, approxi-
mately 3 times as many organisms were isolated from the
lid margin compared to the control group (P = 0.0223).
There was no statistically significant difference between
the groups in the total positive culture from the conjunc-
tival sac (P = 0.5409).
4. Discussion
An analysis of the bacteria present at the edge of the eye-
lids and the conjunctiva (Tables 1 and 2) demonstrated
that increased bacterial contamination levels were sub-
stantially more pronounced at the edge of the eyelids
after the ocular compression.
This finding indicates that the probable source of con-
tamination was the lid margin, specifically the mei-
bomian gland ducts. The impact of pressure on the eye-
Table 1. Characteristic changes in the lid margin bacterial
flora after preoperative ocular compression.
Lid margin
Isolated bacteria Study group
(n = 75) Control group
(n = 31)
staphylococci 12 (16%) 2 (2.8%)
Staphylococcus aureus 2 (2.8%) 1 (3.2%)
Streptococcus viridans 2 (2.8%) 0 (0%)
Gram-positive bacilli 7 (9.3%) 0 (0%)
Total positive culture 23 (30.7%)* 3 (9.7%)
*P = 0.0223 compared with control.
Table 2. Characteristic changes in the conjunctival sac bac-
terial flora after preoperative ocular compression.
Conjunctival sac
Isolated bacteria Stu dy group
(n = 75) Control group
(n = 31)
staphylococci 7 (9.3%) 5 (16.1%)
Staphylococcus aureus 2 (2.8%) 0 (0%)
Streptococcus viridans 2 (2.8%) 0 (0%)
Gram-posi t iv e bacilli 6 (8.5%) 0 (0%)
Total positive culture 16 (21.3%)* 5 (16.1%)
*In one cas e, 2 strains were isolated.
ball indirectly triggers an increase in the meibomian
gland secretion; multiple studies have demonstrated an
increased frequency of meibomitis in patients undergoing
cataract surgery [5,6]. Meibomitis has a bacterial origin,
which likely exp lains the contamination o f the lid margin
after the compression. In addition, there was less time for
the released secretion to move into the conjunctival sac
during the evaluated procedure, which likely explains
why less significant levels of bacterial contamination
were observed in the conjunctival sac. Although all of
the patients received a 0.5% levofloxacin ophthalmic
solution preoperatively, this administration could not
prevent contamination in the lid margin after the com-
pression, which is likely explained by the fact that the
bacteria reside deep within the meibomian glands. In
addition, the meibomian gland secretions contain a large
proportion of fat, which makes the lid margin hydropho-
bic and thus impenetrable by the 0.5% levofloxacin oph-
thalmic solution.
It is well known that the eyelid edges can negatively
impact eye wounds, which is why eyelids are often
covered with an adhesive film. Although this technique is
beneficial and has become the modern standard in
ophthalmic surgery, we believe the use of this adhesive
film could be improved. For example, the eyelids are
covered in a fatty substance; therefore, the film does not
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Impact of Ocular Compression on Ocular Surface Bacterial Contaminat i o n
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reliably adhere to the eyelid s. Moreover, the liquid filling
the conjunctive sac washes the free edge of the eyelids
and transfers bacteria from the lids to the surgical wound.
We studied the effect of ocular compression using the
modified Honan’s balloon, although the use of an eyelid
speculum may have a similar but less dramatic effect.
Presumably, the factors that contribute to the release of
meibomian gland secretions may be related to the ma-
nipulations performed during retrobulbar or peribulbar
anaesthesia. Theoretically, even eye movements during
surgery and immediately after surgery (performed while
the patient is under topical anaesthesia) could place
pressure on the meibomian glands. Improperly applying
antibiotics on the first postoperative day might also result
in negative consequences. Garcia-Arumi further reported
that the POE rate was higher following the administra-
tion of local anaesthesia compared to retrobulbar anaes-
thesia [7].
The most effective method of suppressing bacterial
surface contamination may be via the isolation of the lid
margin during surgery. We initiated this type of study
and evaluated the effects of covering the lid edges with
textile napkins impreg nated with 0.02% aqueous so lution
of chlorhex idine. The results indicated that the continued
presence of a strong antiseptic intraoperatively reduced
the POE rate [8].
5. Conclusion
Preoperative ocular compression performed with the goal
of reducing IOP was associated with the release of mei-
bomian gland secretions and bacterial contamination of
the eyelids. Thus, reliable intraoperative isolation of the
eyelids and the postoperative application of antibiotics
are required for effective POE prophylactic measures.
6. Acknowledgements
The authors thank the individuals who participate in this
study. None of the authors had financial or personal con-
flict of interest with regard to this study. This paper was
derived from a PhD thesis.
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