Purpose: To evaluate the serum 25-hydroxy vitamin D, vitamin B12, and folic acid (FA) levels in progressive and nonprogressive patients with keratoconus (KCN). Methods: Fifty-five patients with KCN (28 progressive and 27 nonprogressive) who were followed up for at least 12 months were recruited and separated into 2 groups according to corneal topographic progression criteria. Age- and sex-matched 30 healthy individuals formed the control group. Serum vitamin D, B12, FA, and Ca levels were compared among control, nonprogressive, and progressive groups. The effect of gender, age, vitamin D, B12, and FA parameters on KCN progression was investigated. Results: Serum vitamin D levels were 12.77 ± 5.52, 11.78 ± 4.32, and 17.40 ± 5.12 ng/mL in nonprogressive, progressive, and control groups, respectively. The serum vitamin D levels in KCN groups (nonprogressive and progressive) were significantly lower than the control group (P = 0.002 and P < 0.001, respectively). There was no significant difference between all groups in serum vitamin B12, FA, and Ca levels (P > 0.05). Decreased vitamin D levels significantly increased nonprogressive KCN probability 1.23 times and progressive KCN probability 1.29 times more than the control group (P = 0.002, 95% confidence interval, 0.708–0.925; P < 0.001, 95% confidence interval, 0.668–0.888, respectively). Conclusions: Serum vitamin D levels were significantly decreased in both KCN groups. However, serum vitamin B12, FA, and Ca levels were similar in all groups. Serum vitamin D evaluation of patients with KCN at onset and follow-up examinations may help to predict the course of the disease.

Purpose: To investigate the acute effects of brinzolamide, betaxolol, and latanoprost (drugs commonly used in the medical management of glaucoma) on choroidal thickness using enhanced depth imaging optical coherence tomography (EDI-OCT). Methods: Ninety healthy volunteers were evaluated in this prospective study. Participants were randomly divided into 3 groups. Brinzolamide, betaxolol, and latanoprost were administered into the left eyes of the first group (n = 30), second group (n = 30), and third group (n = 30), respectively, and artificial tear (Sodium hyaluronate) was instilled into the right eyes of all participants. Subfoveal choroidal thickness (SFCT) was measured using EDI-OCT before and 45 minutes after administration of the antiglaucomatous drops. Results: SFCT revealed a significant increase in the left eye (administered antiglaucomatous drop) in the brinzolamide (p = 0.001) and betaxolol groups (p = 0.049) and a significant increase also in the right eye (administered artificial drop) in the brinzolamide (p = 0.001) and betaxolol groups (p = 0.001). However, SFCT did not reveal a significant increase in the left eye (p = 0.213) or in the right eye (p = 0.062) in the latanoprost group. Conclusion: Brinzolamide and betaxolol caused an increase in SFCT, while latanoprost had no significant effect on SFCT.

Precis: Serum netrin-1 levels are significantly lower in patients with pseudoexfoliation syndrome (PES) and pseudoexfoliative glaucoma (PEG) compared to the control group. Purpose: To investigate serum netrin-1 levels in PES and PEG patients and to determine the relevance of this molecule in the etiopathogenesis of PES and PEG related diseases. Patients and Methods: This prospective study included 29 PES and 17 PEG patients in the study groups and age-sex matched 47 cataract patients without pseudoexfoliative accumulation as a control group. Serum netrin-1 levels were measured by enzyme-linked immunosorbent assay. Results: Serum netrin-1 level was significantly lower in the PES and PEG groups compared to the control group (P=0.007). Multinominal logistic regression analysis was performed in terms of netrin-1 levels ≤712.9▒pg/mL; >712.9▒pg/mL and gender which may affect PES and PEG. It were found that netrin-1 was a significant negative predictor for PES (OR:3.45 [95% CI: 1.230–9.716], P=0.019) and PEG (OR: 3.57 [95%CI: 1,008–12.669], P=0.049,), respectively. Conclusion: Decreased serum netrin-1 levels were detected in PES and PEG patients, similar to atherosclerosis and Alzheimer’s disease. Inflammation lays behind in the common pathogenesis of these diseases. Therefore, netrin-1 promises a potential anti-inflammatory role.

To evaluate alterations in the serum concentrations of vascular endothelial growth factor (VEGF) and netrin-1 after intravitreal bevacizumab (BCZ) injection for the treatment of diabetic macular edema (DME). This prospective case-control study included a total of 50 participants assigned to one of three groups, including 10 individuals with DME and non-proliferative diabetic retinopathy (NPDR), 13 with DME, and proliferative diabetic retinopathy (PDR), and 27 healthy individuals as a control group. Serum VEGF and netrin-1 concentrations were measured by enzyme-linked immunosorbent assays (ELISAs) immediately before, as well as 1 week and 1 month after, intravitreal BCZ injection. The mean VEGF serum concentrations in the PDR and NPDR groups were 388.4 and 196.9 pg/mL at baseline, respectively. After 1 week, these concentrations changed to 193.41 and 150.23 pg/mL, respectively (P = 0.001 and P = 0.005, respectively); after 1 month, the concentrations were 97.89 and 76.46 pg/mL, respectively (P = 0.001 and P = 0.009, respectively). The mean netrin-1 serum concentrations in the PDR patients and NPDR groups were 318.2 and 252.7 pg/mL at baseline, respectively. After 1 week, these concentrations increased to 476.6 and 416.3 pg/mL, respectively (P = 0.033 and P = 0.005, respectively), and after 1 month, they were 676.6 and 747.5 pg/mL, respectively (P = 0.001 and P = 0.005, respectively). The correlation analysis revealed a significant inverse relationship between changes in serum VEGF and netrin-1 concentrations in both the PDR and NPDR groups (r = − 0.685, P = 0.029). Intravitreal BCZ injections work systemically to significantly decrease serum VEGF levels, leading to a significant upregulation in the concentration of another angiogenic mediator, netrin-1.