Prevalence of pterygium in Iran: a systematic review and meta-analysis study

Background and aim

Pterygium is one of the most prevalent pathologies involving the cornea, which can lead to various vision signs and even reduction in eyesight. No accurate estimate has been reported about the prevalence of pterygium in Iran. Hence, this study aimed to determine the pterygium prevalence in Iran by meta-analysis method.

Methods

Searching for data of the last eleven years (from 2004 to 2015) was conducted using the keywords of pterygium, eye, and Iran in International and domestic indexing services and databases including Iranmedex, Scientific Information Database (SID), Magiran, Irandoc, Medlib, IranPsych, Science Direct, Web of Science (Thomson Reuters), PubMed, and Scopus. The data were analyzed using the meta-analysis method (the random effects model). The disharmony of the studies was investigated using the I2 index. The data were analyzed by STATA Ver.11 software.

Results

In 5 studies conducted in Iran, with a sample size of 10,838 people between 2004 and 2015, the extent of the prevalence was estimated to be 11% (95% CI: 3 to 18%). Also, the prevalence of pterygium in women and men was 18% and 13%, respectively.

Conclusion

According to the published reports from Iran and its comparison with other points in the world, the prevalence of pterygium in Iran is high, especially among women.

The prevalence of visual disorders in Iranian students: A meta-analysis study and systematic review

Background

Visual defects have dramatic effects on health, self-esteem, and educational function of students, and delayed diagnosis will cause complications, like academic failure and psychologic disorders.

Objective

The present study aimed to investigate the prevalence of ocular disorders in Iranian students in a systematic review.

Methods

We searched databases, including PubMed, SID, Magiran, Google Scholar, and Iranmedex using the following keywords in Persian and English: disorders, vision, amblyopia, refractive errors, astigmatism, student, and Iran with all the possible combinations, important, chief, and sensitive words. Search resulted in 28 articles, conducted during a period from 1996 to 2014 in Iran and their data was analyzed using meta-analysis and random effects model. Heterogeneity of studies was assessed using I2 index, and data was finally analyzed with R Software and STATA (Version 11.2).

Results

Total number of subjects in the study was 1,117,274, aged 2 to 18 years. The prevalence of disorders related to amblyopia, refractive error, and strabismus was 8%, 7% and 1%, respectively. The greatest amount of refractive error was related to astigmatism (19%) followed by myopia (17%).

Conclusion

According to the study results, the prevalence of visual disorders among Iranian students indicated the critical necessity of screening programs for prevention of visual disorders in this age group.

Age-dependent antibody response to Plasmodium falciparum merozoite surface protein 2 (MSP-2)

Merozoite surface protein 2 (MSP-2), a very immunogenic malaria antigen, is a highly polymorphic 45-53 kDa merozoite surface protein, which is regarded as a promising vaccine candidate. The highly polymorphic nature of MSP-2 suggests that the molecule can be involved in protective immunity against malaria. The antibody responses to MSP-2 antigen are mostly directed against polymorphic and dimorphic regions of the protein. The current study aimed at testing the reactivity of human sera from a malaria-endemic area of Gambia against MSP-2 regions 2, 3 and 4 compared to crude schizont extract in a period of 20 years. The age-dependent immunity was analysed in a manner of cross-sectional study (the data of the first visit) and also a longitudinal study design (analysing the data at four different time points from 1960 to 1980) testing the sera of 178 individuals randomly selected from the Keneba Serum Collection by using MSP-2 recombinant protein. The total IgG responses were measured by ELISA. Kolmogorov-Smirnov was used to check the normal distribution of OD, Hb and parasitaemia, and then Spearman correlation was applied to analyse the data. Most sera recognized, predominantly, the variable regions of the MSP-2, particularly the domain 3. The IgG response against all the antigens increased with age. The IgG responses against domain 3 of MSP-2 were associated with an increase in haemoglobin levels but a decrease in parasitaemia, suggesting that this immune response may be one of the most useful means for further studies on protective immunity against malaria.

The inverse association of serum HBV DNA level with HDL and adiponectin in chronic hepatitis B infection

BACKGROUND

The natural history of hepatitis B virus (HBV) is complex and influenced by the level of viral replication and host factors. The hepatoprotective role of high density lipoproteins (HDL) and adiponectin as host factors on HBV persistence is less well understood.

METHODS

To investigate correlation between HBV DNA level with clinical parameters in patients with chronic hepatitis B, 92 male subjects with HBV infection without any risk factors for diabetes were enrolled in this study. Age and BMI of the study population were matched and HBV DNA, ALT, tumor necrosis factor alpha (TNF-α), adiponectin and lipid levels was measured.

RESULTS

Serum HBV DNA correlated inversely with serum HDL level (r = -0.23; P = 0.014). The median of log copies/ml for HBV DNA (3.67) was considered as cut off point. Patients with HBV DNA level higher than cut off point had lower adiponectin (8.7 ± 5.3 vs 10.7 ± 4.9 μg/ml p = 0.05). Also, adiponectin had a negative correlation with TNF-α (r = -0.21, P = 0.04) and positive correlations with HDL (r = 0.18, P = 0.043). Multivariate regression models show that serum HDL level is an independent factor to predict serum HBV DNA.

CONCLUSION

Our findings showed that higher HBV DNA levels are associated with lower HDL and adiponectin but induced TNF-alpha values.