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: This study investigated the toxic effects of an antineoplastic agent, cisplatin (CIS), on retinal cells and the potential capacity of astaxanthin (ASTA) to elicit a future therapeutic protocol in CIS-induced retinal toxicity. Materials and methods: Six groups were formed for the assessment; control (healthy; Group 1), olive oil (olive oil only; Group 2), ASTA control group (ASTA only, Group 3), the single intraperitoneal (IP) dose of 16 mg/kg CIS (CIS only group; Group 4), 16 mg/kg CIS +25 mg/kg (IP) ASTA (Group 5), and 16 mg/kg CIS +75 mg/kg (IP) ASTA (Group 6). On the third day after CIS administration, rats in all groups were sacrificed under anesthesia and the analysis of the biochemical parameters and histopathological levels were performed. Results: A significant decrease in GSH levels and increases in MDA, eNOS, and 8-OHdG expressions were recorded. Additionally, CIS treatment had caused acidophilic staining in retinal histological appearance. ASTA treatment reduced the increases in MDA, eNOS, and 8-OHdG levels following CIS administration and increased the levels of GSH expressions, as well. Conclusions: These results may suggest that the ASTA molecule as a promising option to prevent retinal toxicity in patients receiving CIS treatment for malignant tumors.

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.

Purpose/Aim of the Study: Detailed analysis of retinal structure such as the retinal nerve fiber layer can be performed by spectral-domain optical coherence tomography (OCT). There are no published studies concerning a relationship between retinal nerve fiber layer and human sphenoid sinus volumes. We investigated this relationship. Material and Methods: Spectral-domain OCT. The peripapillary retinal nerve fiber layer (RNFL) thickness and sphenoid sinus volume estimation of both sides of sex-matched patients were retrospectively analyzed. Results: The mean RNFL thicknesses at the left side (91.8 μm) were significantly smaller than the right side (94.5 μm) (P = 0.040). However, the mean left sinus volume (44.5 cm³) is larger than the right side, (34.5 mm³) (P < 0.005). Left and right differences of both parameters are statistically significant (P < 0.05). Conclusion: There is a negative correlation between mean RNFL thicknesses and mean sinus volumes. To our knowledge, this article is the first report demonstrating the asymmetry relationship between RNFL and sphenoid sinus volumes.