-
Investigative Ophthalmology & Visual... Sep 2014To determine the association of cigarette smoking with pterygium. (Meta-Analysis)
Meta-Analysis Review
PURPOSE
To determine the association of cigarette smoking with pterygium.
METHODS
Potentially eligible studies published from the year 1946 to December 28, 2013 were identified from MEDLINE, EMBASE, and Cochrane Library databases, and reference lists. All studies that evaluated smoking as an independent factor for pterygium were identified. Study-specific odds ratios (ORs) were combined using the random-effects model when P < 0.1 in the test for heterogeneity, or otherwise the fixed-effects model was used. Meta-regression, sensitivity analysis, and evaluation of potential biases were undertaken. The ORs with 95% confidence intervals (CIs) of smoking as an associated factor for pterygium were analyzed.
RESULTS
We included 24 articles incorporating 95,279 participants from 20 cross-sectional studies, 2 hospital-based case-control studies, and 2 population-based cohort studies. The combined OR of cigarette smoking (current or ever smoked) for risk of pterygium was 0.82 (95% CI, 0.69-0.97; P = 0.025). The results remained consistent among current smokers (OR, 0.68; 95% CI, 0.61-0.76; P = 4.57 × 10(-12)), but not in ex-smokers (OR, 1.05; 95% CI, 0.87-1.27; P = 0.59). The impact of ultraviolet light (UV) exposure (P = 0.082) and sex (P = 0.553) on the effect of smoking was insignificant in meta-regression. Sensitivity analysis confirmed the protective effect and nonrelevance of these two study-level variables. Begg's funnel plots and Egger's test showed minimal publication bias.
CONCLUSIONS
The results of this meta-analysis show that cigarette smoking was associated with a reduced risk of pterygium, especially in current smokers. This effect may be independent of UV exposure and sex. Investigations are needed to unveil its molecular basis serving therapeutic purposes.
Topics: Global Health; Humans; Morbidity; Prognosis; Pterygium; Risk Assessment; Risk Factors; Smoking
PubMed: 25190665
DOI: 10.1167/iovs.14-15046 -
BMJ Open Nov 2013Pterygium is considered to be a proliferative overgrowth of bulbar conjunctiva that can induce significant astigmatism and cause visual impairment; this is the first...
OBJECTIVE
Pterygium is considered to be a proliferative overgrowth of bulbar conjunctiva that can induce significant astigmatism and cause visual impairment; this is the first meta-analysis to investigate the pooled prevalence and risk factors for pterygium in the global world.
DESIGN
A systematic review and meta-analysis of population-based studies.
SETTING
International.
PARTICIPANTS
A total of 20 studies with 900 545 samples were included.
PRIMARY OUTCOME MEASURE
The pooled prevalence and risk factors for pterygium.
RESULTS
20 studies were included. The pooled prevalence of pterygium was 10.2% (95% CI 6.3% to 16.1%). The pooled prevalence among men was higher than that among women (14.5% vs 13.6%). The proportion of participants with unilateral cases of pterygium was higher than that of participants with bilateral cases of pterygium. We found a trend that the higher pooled prevalence of pterygium was associated with decreasing geographical latitude and age in the world. The pooled OR was 2.32 (95% CI 1.66 to 3.23) for the male gender and 1.76 (95% CI 1.55 to 2.00) for outdoor activity, respectively.
CONCLUSIONS
The pooled prevalence of pterygium was relatively high, especially for low latitude regions and the elderly. There were many modifiable risk factors associated with pterygium to which healthcare providers should pay more attention.
PubMed: 24253031
DOI: 10.1136/bmjopen-2013-003787