Hindawi Publishing Corporation
The Scientific World Journal
Volume 2013, Article ID 643764, 4 pages
Long-Term Effects of Cataract Surgery on Tear Film Parameters
Vincent D. Venincasa,1,2Anat Galor,1,2William Feuer,2David J. Lee,3
Hermes Florez,1,4and Michael J. Venincasa2
1Department of Ophthalmology, Miami Veterans Affairs Medical Center, 1201 NW 16th Street, Miami, FL 33125, USA
2Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, 900 NW 17th Street, Miami, FL 33136, USA
3Department of Epidemiology and Public Health, University of Miami, 1801 NW 9th Avenue, Miami, FL 33136, USA
4Department of Endocrinology and Geriatrics, University of Miami, 1611 Northwest 12th Avenue, Miami, FL 33136, USA
Correspondence should be addressed to Anat Galor; firstname.lastname@example.org
Received 1 November 2012; Accepted 10 December 2012
Academic Editors: Z. Bashshur, C. Haritoglou, T. Kubota, and F. M. Penha
Copyright © 2013 Vincent D. Venincasa et al. This is an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly
Purpose.To examinethedifferences intearfilmparameters morethan3monthspostsurgeryineyes withcataract surgery(surgical
Center (VAMC) who had cataract surgery by phacoemulsification in one eye more than 3 months prior to the study date and
had no history of surgical intervention in their fellow eye. Tear film parameters were measured in both eyes and compared using
McNemar tests for dichotomous variables and paired and single sample t-tests for continuous variables. Results. Mean patient age
was 73 (standard deviation (SD): 11); 26 patients (90%) identified themselves as White and 7 (24%) as Hispanic. The mean number
of days between surgery and this study was 952 (SD: 1109). There were no statistical differences between the surgical eye and the
enough to exclude a substantial effect of cataract surgery. The elapsed time between cataract surgery and measurement of the tear
parameters did not appear to affect the difference in parameters between the two eyes. Conclusion. We found that eyes that had
cataract surgery more than 3 months prior to testing had no differences in their tear film parameters compared to eyes without a
history of surgery.
Dry eye syndrome (DES) is a complex disease that presents
with many symptoms, including ocular discomfort, tear film
instability, and visual changes . It can greatly affect patient
quality of life by impairing the ability to drive, read, use
a computer, and watch television among other effects .
Various studies have estimated the prevalence of DES to be
between 5% and 34% of the population . One of the major
risk factors for developing novel DES or exacerbating pre-
 or LASIK surgery .
Over 1.5 million cataract surgeries are performed each
of over $3.4 billion . By nature of the procedure, cataract
surgery typically results in some denervation of the cornea
turn can lead to dry eye symptoms .
With the incidence of cataracts and number of cataract
surgeries performed rapidly increasing , it is important to
study the long-term effects of this procedure. In the LASIK
literature, dry eye symptoms after LASIK surgery adversely
affected patient satisfaction and willingness to have the
surgery again . Studies have shown that cataract surgery
worsens dry eye symptoms in patients with preexisting DES
DES in at least the first 2 months postsurgery [4, 10].
While the effects of cataract surgery on DES in the short
term are well described [4, 10–13], there is a knowledge
gap on the long-term effects of cataract surgery on dry
eye symptoms and tear film parameters. This study aims to
2 The Scientific World Journal
narrow the knowledge gap by examining whether or not tear
film parameters become comparable in eyes with or without
surgery in the long term.
2. Materials and Methods
2.1. Study Population. Patients were prospectively recruited
from the Miami VAMC clinic without regard to tear film
status. Patients were excluded from the study if they were
under 50 years old, had anterior segment abnormalities such
as pterygium or corneal edema, used any ocular medication
other than artificial tears/topical cyclosporine, or tested pos-
itive for human immunodeficiency virus (HIV), sarcoidosis,
or another collagen vascular disease. To be included in our
specific study, patients must have had cataract surgery by
phacoemulsification with a corneal incision in one eye more
than 3 months prior to data collection, and no cataract
surgery in the other eye. From a collection of 263 men
that were recruited to undergo tear film testing, 29 met our
specific study criteria. The Miami Veterans Affairs Institu-
tional Review Board reviewed and approved the prospective
examination of patients for this study, which was conducted
in accordance with the principles of the Declaration of
Helsinki. Informed consent was obtained from all study
past medical history, and current medical information for
each patient. The ocular surface examination included tear
osmolarity (TearLAB, San Diego, CA, USA, obtained once
in each eye), tear breakup time (range 0–15, obtained twice
and averaged in each eye), corneal staining (punctuate
epithelial erosions (PEE), range 0–5) , Schirmer’s testing
with anesthesia, and morphologic and qualitative eyelid and
meibomian gland information. The morphologic parame-
ters we collected included the degree of eyelid vascularity
(0-none; 1-mild engorgement; 2-moderate engorgement; 3-
severe engorgement)  and the degree of inferior eyelid
meibomian orifice plugging (0-none; 1-less than 1/3 lid
involvement; 2-between 1/3 and 2/3 lid involvement; 3-
(meibum) quality was rated on a scale of 0 to 4 (0-clear;
1-cloudy; 2-granular; 3-toothpaste; 4-no meibum extracted)
. All data was compiled into a standardized database.
2.3. Main Outcome Measures. The main outcomes measured
eters in the study population in the eyes that had cataract
surgery versus the eyes that had no surgery.
2.4. Statistical Analysis. All statistical analyses were per-
package. Descriptive statistics were used to characterize tear
used to compare dichotomous variables. Paired and single
sample t-tests were used to compare continuous variables.
A 𝑃𝑃 value of less than 0.05 was considered statistically
Table 1: Demographic information of study population (patients
who had cataract surgery in one eye and no history of surgery in
the other eye). (SD: standard deviation).
Number of patients
Age, mean (SD) (range)
White, n (%)
Hispanic, n (%)
Never, n (%)
Excellent, n (%)
Days after surgery, mean (SD) (range)
73.2 (10.7) (58–93)
952 (1109) (95–3650)
The difference of each tear film parameter between the
two patient eyes was calculated. A 95% confidence interval
(CI) was calculated for each of the differences in the tear
film parameters. This interval provides, for each parameter,
a likely range for the true difference between the surgical and
for each parameter could be considered wide or narrow,
we expressed it as a percentage of that parameter’s range of
measurements. The 1.5 × interquartile range (IQR) rule was
in a data set, if a value is less than the 25th percentile or
used to check for outliers in the continuous variables. The
IQR is the difference between the 25th and 75th percentile
greater than the 75th percentile by more than 1.5 × IQR, it
relationship between these differences and time between the
surgery and study tests. The strength of association between
the difference in tear film parameters and time after surgery
approximates the real data. 𝑟𝑟2> 0.7 is considered a strong
is considered an outlier.
Linear regression analysis was performed to evaluate the
was summarized with linear regression (𝑟𝑟2). 𝑟𝑟2ranges from
0 to 1 and is a measure of how well the regression line
correlation and 𝑟𝑟2< 0.3 is considered a weak correlation.
3.1. Study Population. Twenty-nine male patients were
included in the analysis. Demographic characteristics of the
study population can be found in Table 1. Mean patient age
was 73 (standard deviation (SD): 11). Twenty-six patients
(90%) identified themselves as white and 7 patients (24%)
as Hispanic. The mean number of days between surgery and
study testing was 952 (SD: 1109, range: 95–3650).
The Scientific World Journal3
Table 2: Tear film parameters of the study population comparing non-surgical eye to surgical eye.
Tear film parameters
Tear osmolarity, mean (SD) (range)
Number of patients (%)
Tear break-up time, mean (SD) (range)
Number of patients (%)
Schirmer’s, mean (SD) (range)
Number of patients (%)
MG orifice plugging
Nonsurgical eye (NSE)
306.68 (13.41) (285–339)
6 (21.4%) with value >1
13.48 (8.00) (5–30)
9 (31.0%) with value >1
Surgical eye (SE)
306.21 (13.43) (284–346)
6 (21.4%) with value >1
12.34 (7.49) (5–30)
6 (20.7%) with value >1
𝑃𝑃 value Mean differenceI(SD)
1 0.071 (0.86)
2 (7.1%) with value >325
8.66 (5.40) (1–15)
5 (17.2%) with value <5
1 (3.6%) with value >325
8.86 (4.78) (1–15)
3 (10.3%) with value <5
14 (48.3%) with value <5
5 (17.2%) with value >1
8 (27.6%) with value <5
5 (17.2%) with value >1
6 (20.1%) with value >17 (24.1%) with value >1
(IMean Difference = nonsurgical eye − surgical eye;IICI = confidence interval).
3.2. Differences in Tear Film Parameters between Eyes. There
were no statistical differences between the eye that had
cataract surgery (surgical eye) and the eye without a history
of surgery (nonsurgical eye) in any of tear film parameters
(Table 2). There were more nonsurgical eyes with tear break-
up times less than 5 compared to surgical eyes, but this was
notstatisticallysignificant(𝑃𝑃 = 0.11,95%confidenceinterval
(CI), −1.77 to 1.36). Surgical eyes had a lower mean score on
outliers were present as classified by the 1.5 × IQR rule,
Schirmer’s test but this difference was also not statistically
significant (𝑃𝑃 = 0.25, 95% CI, −0.82 to 3.10).
effect of cataract surgery. For all continuous variables, no
All of the parameters’ 95% CIs were ≤12% of their respec-
tive ranges and thus narrow enough to exclude a substantial
were not excessively large due to the presence of outliers.
3.3. Correlation between Tear Film Parameters and Time from
Surgery. No significant correlations were seen between the
difference in tear film parameters for the surgical versus
nonsurgical eye and time after surgery (𝑟𝑟2less than 0.14 in
all cases), suggesting that after 3 months tear film parameters
were similar between the two eyes.
Prior studies have examined the effect of cataract surgery on
tear film parameters and reported short-term disruptions in
tear function. Ram et al. in 23 postcataract surgery patients
(25 eyes) demonstrated decreased Schirmer scores and tear
break-up time (TBUT) at various time points up to 2 months
postoperation compared to preoperative values . Li et
al, in 37 postcataract surgery patients (50 eyes), similarity
found decreased Schirmer and TBUT values at 1-week, 1-
month, and 3-month time points compared to preoperative
values . These studies followed patients for a limited
time period after surgery, and while there was a trend
towards normalization of values, short followup limited the
their baseline values. Our study’s purpose, therefore, was to
evaluate whether patients who had cataract surgery at least
3 months prior to testing had similar tear film parameters
between the surgical and nonsurgical eyes. Indeed, our data
suggests that tear film parameters recover after surgery, as all
studied parameters were statistically similar between eyes.
tests such as Schirmer’s, TBUT, and corneal staining, but
also other less established objective measures of tear func-
tion including tear osmolarity, eyelid vascularity, meibomian
gland secretion and orifice plugging in the long term after
cataract surgery. This is an important study since it can begin
to lay the foundation of our knowledge on what long-term
changes occur in eyes that had cataract surgery.
One issue to consider when interpreting the results is the
small sample size. In a small study, such as this one, a finding
of no significant difference cannot be taken to mean that no
difference exists. Therefore, we constructed 95% confidence
intervals to assess the likely size of any differences between
have missed. For all variables, the sizes of the confidence
Further, all continuous variables were without outliers (as
classified by 1.5 × IQR), so it is unlikely that distribution of
while keeping in mind the study limitations. This study
design was different than other cataract surgery studies as
we did not measure tear film parameters in the same eye
longitudinally. We can therefore only compare the values
between eyes without commenting on whether tear film
parameters “normalized” in the operated eye. Although it
has been shown that fellow eyes have a substantial degree
of correlation with respect to tear film parameters , a
our findings. Furthermore, our study could not evaluate the
individual effects of race, age, and ethnicity on tear film
function. However, by nature of its paired design, these
factors were effectively controlled for, as any effect found
would be independent of these demographic parameters.
Finally,this study could notevaluate the impact between tear
film parameters and patients’ symptoms. The main source
of morbidity in DES is its symptoms and prior studies have
shown that correlation between symptoms and clinical tests
these ranges was overlarge due to skewed distributions.
As with all studies, our conclusions must be interpreted
4The Scientific World Journal
patients who experience increased ocular surface symptoms
after surgery have an eventual decrease in their discomfortto
Despite these limitations,our study suggests that patients
undergoing cataract surgery can be counseled that their tear
film function will mirror that of the fellow eye 3 months
after cataract surgery. Increasing patient understanding and
giving realistic expectations often improves overall patient
satisfaction and the physician-patient relationship. We hope
that these findings open the door for future research to
confirm our results and further study the mechanisms of
tear film disruption and changes after cataract extraction,
A. Galor received the VA Career Development Award. This
paper received unrestricted funds from Research to Prevent
 M. A. Lemp, C. Baudouin, J. Baum et al., “The definition
and classification of dry eye disease: report of the definition
and classification subcommittee of the international Dry Eye
WorkShop,” Ocular Surface, vol. 5, no. 2, pp. 75–92, 2007.
 B. Miljanovi´ c, R. Dana, D. A. Sullivan, and D. A. Schaumberg,
“Impact of dry eye syndrome on vision-related quality of life,”
 J. A. Smith, J. Albenz, C. Begley et al., “The epidemiology of
international Dry Eye WorkShop,” Ocular Surface, vol. 5, no. 2,
pp. 93–107, 2007.
 X. M. Li, L. Hu, J. Hu, and W. Wang, “Investigation of dry eye
disease and analysis of the pathogenic factors in patients after
cataract surgery,” Cornea, vol. 26, no. 9, supplement 1, pp. S16–
 I. Toda, N. Asano-Kato, Y. Komai-Hori, and K. Tsubota, “Dry
eye after laser in situ keratomileusis,” American Journal of
Ophthalmology, vol. 132, no. 1, pp. 1–7, 2001.
from cataract surgery?” Cleveland Clinic Journal of Medicine,
vol. 75, no. 3, pp. 193–200, 2008.
 E. D. Donnenfeld, K. Solomon, H. D. Perry et al., “The effect of
hinge position on corneal sensation and dry eye after LASIK,”
Ophthalmology, vol. 110, no. 5, pp. 1023–1030, 2003.
 A. Foster, “Vision 2020: the cataract challenge,” Journal of
Community Eye Health, vol. 13, no. 34, pp. 17–19, 2000.
 J. A. Hovanesian, S. S. Shah, and R. K. Maloney, “Symptoms
of dry eye and recurrent erosion syndrome after refractive
surgery,” Journal of Cataract and Refractive Surgery, vol. 27, no.
4, pp. 577–584, 2001.
 Y. K. Cho and M. S. Kim, “Dry eye after cataract surgery
and associated intraoperative risk factors,” Korean Journal of
Ophthalmology, vol. 23, no. 2, pp. 65–73, 2009.
of ocular surface disease,” Current Opinion in Ophthalmology,
vol. 23, pp. 68–72, 2012.
 J. Ram, A. Gupta, G. S. Brar, S. Kaushik, and A. Gupta,
“Outcomes of phacoemulsification in patients with dry eye,”
Journal of Cataract and Refractive Surgery, vol. 28, no. 8, pp.
 T. Oh, Y. Jung, D. Chang, J. Kim, and H. Kim, “Changes in
the tear film and ocular surface after cataract surgery,” Japanese
Journal of Ophthalmology, vol. 56, pp. 113–118, 2012.
 A. J. Bron, V. E. Evans, and J. A. Smith, “Grading of corneal
and conjunctival staining in the context of other dry eye tests,”
Cornea, vol. 22, no. 7, pp. 640–650, 2003.
 G. N. Foulks and A. J. Bron, “Meibomian gland dysfunction:
a clinical scheme for description, diagnosis, classification, and
grading,” Ocular Surface, vol. 1, no. 3, pp. 107–126, 2003.
 A. Tomlinson, A. J. Bron, D. R. Korb et al., “The international
nosis subcommittee,” Investigative Ophthalmology and Visual
Science, vol. 52, no. 4, pp. 2006–2049, 2011.
 R. J. Glynn and B. Rosner, “Accounting for the correlation
mology, vol. 110, no. 3, pp. 381–387, 1992.
 K. Tsubota, P. Ashell, M. Dogru et al., “Design and conduct of
clinical trials: report of the clinical trials subcommittee of the
international Dry Eye WorkShop,” Ocular Surface, vol. 5, no. 2,
pp. 153–162, 2007.