In order to determine the expression level of miR 125b in every group relative real-time PCR was performed. The level of miR 125b expression was increased in each of the study groups (PEXg, Gg and PEXGg) compared to the control group (Figure 1)
The qualitative analysis revealed statistically significant 3.33 time higher miR 125b levels in PEXg cohort as compared to the Cg cohort (p=0.046, chi-square test, table 1). There were no statistically significant differences in miR 125b levels between the samples from the Gg and Cg cohorts.
Table 1 shows the mean and standard deviations of RQ values, however the RQ distributions are right-skewed. Therefore the ANOVA test was used after the RQ logarithm transformation. An LSD test as post hoc test was used after ANOVA. No differences in sex distribution between groups has been found (p=0.4822).
In the PEXg vs all others (Gg and PEXGg), the number of patients with the RQ value >0.6 was increased by 10%, while 10% fewer patients had an RQ value < -0.3. This further supports the statistical difference between the described groups (Figure 2).
The quantitative analysis of miR 125b expression conducted between PEXg+PEXGg (combined group of all the patients that have the pseudoexfoliation syndrome with or without glaucoma) and Cg revealed a statistically significant difference (p=0,04, t-test) (Figure 3).
Additionally the logistic regression model (Figure 4) revealed the statistically significant correlation (probability >50%) between level of RQ and defined in the study diagnosis (A) existing PEX with or without glaucoma, (B) existing Glaucoma with or without PEX; the PEXG - a secondary glaucoma is combined with primary open angle glaucoma; (C) only PEX, (D) only Glaucoma vs control group. The PEXG group is an additional factor that reverses the 95%CI RQ values from predominantly positive in the PEXg and Gg into the predominantly negative in the combined groups such as PEXg+PEXGg and PEXGg+Gg. This analysis with wide 95%CI range should be specified in further studies. The p-values and 95%CI ranges are: 0.0013, -6.94 – 2.17; 0.0056, -14.32 – 2.09; 0.0002, 1.35-7.90; 0.0027, 0.95 – 12.89 respectively for PEXg+PEXGg, PEXGg+Gg, PEXg and Gg.
Factors that may affect miR 125b expression
There were no statistically significant correlations between the levels of miR 125b and the age of the patients.
During the assesment of relationships between levels of miR 125b and important factors obtained from patients‘ history records (smoking, drops for glaucoma) only one statistically significant difference was found. A lower level of RQ miR 125b (p=0,01) was found in patients who smoked compared to those who did not (Table 2).