vitamin-b-12 and Keratoconus

To evaluate blood levels of vitamin B12, folic acid, riboflavin, and homocysteine in keratoconus (KC) and healthy subjects.. Eskişehir Osmangazi University, Eskişehir, Turkey.. Cross-sectional study.. 100 KC patients (patient group) between the ages of 18 to 35 years and 200 healthy individuals (control group) in the same age range were included in the Eskişehir Osmangazi University Hospital Eye Clinic between October 2019 and March 2020. In all cases, a complete ophthalmologic examination and corneal tomography evaluation with a Pentacam Scheimpflug camera were performed. In blood samples, vitamin B12 and folic acid levels were measured using an electrochemiluminescence immunoassay analyzer, and homocysteine and riboflavin levels were measured using high-performance liquid chromatography. Chi-square tests were used in the analysis of categorical variables, and Mann-Whitney U and Kruskal-Wallis tests were used in the analysis of numerical variables.. Homocysteine (13.0 ± 6.6 vs 12.1 ± 5.4 μmol/L, P = .190), vitamin B12 (313.5 ± 119.4 vs 322.9 ± 128.3 pg/mL, P = .619), and folic acid (7.0 ± 2.7 vs 7.4 ± 2.9 ng/mL, P = .230) levels were not different between KC (100 eyes of 100 subjects) and control (200 eyes of 200 subjects) groups. The mean riboflavin level was 84.0 ± 21.8 μg/L in the patient group and 183.6 ± 74.3 μg/L in the control group, with a significant difference between the 2 groups ( P < .001). Riboflavin levels were below 180 μg/L in 99% (n = 99) of the cases in the KC group and 53.5% (n = 107) in the control group ( P < .001).. Low blood riboflavin levels in KC patients may be a possible risk factor in the pathogenesis of KC.

Topics: Adolescent; Adult; Cross-Sectional Studies; Folic Acid; Healthy Volunteers; Homocysteine; Humans; Keratoconus; Riboflavin; Vitamin B 12; Young Adult

To evaluate the serum 25-hydroxy vitamin D, vitamin B12, and folic acid (FA) levels in progressive and nonprogressive patients with keratoconus (KCN).. 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.. 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).. 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.

Topics: Adolescent; Adult; Corneal Pachymetry; Corneal Topography; Disease Progression; Female; Folic Acid; Humans; Intraocular Pressure; Keratoconus; Luminescent Measurements; Male; Tonometry, Ocular; Visual Acuity; Vitamin B 12; Vitamin D; Young Adult

To compare the plasma levels of homocysteine between patients with keratoconus and healthy subjects.. Thirty-three keratoconus patients, and 47 age-gender matched healthy subjects were included in this prospective study. The plasma level of homocysteine, folic acid, and vitamin B12 was assessed using the chemiluminescence immunometric method. According to the manufacturer's instructions, the normal plasma level of homocysteine, vitamin B12 and folic acid was accepted as ≤ 13 μm/L, 191-663 pg/mL, and 4.6-18.7 ng/mL respectively. Mann-Whitney U and Spearman's correlation tests were used for pairwise comparisons and correlation analysis, respectively.. There was a statistically significant difference between keratoconus patients and healthy subjects in terms of mean plasma level of homocysteine (15.02 ± 8.01 μm/l in keratoconus patients versus 12.62 ± 8.17 μm/l in healthy subjects, p = 0.01). However, the mean plasma level of either vitamin B12 (263.78 ± 107.2 pg/ml in keratoconus patients versus 264.78 ± 94.2 pg/ml in healthy subjects, p = 0.3), or folic acid (5.98 ± 3.2 ng/ml in keratoconus patients versus 6.72 ± 3.1 ng/ml in healthy subjects, p = 0.1) were not statistically significantly different between two groups. A negative correlation was found between plasma homocysteine level and central corneal thickness (p < 0.001). A positive correlation was found between plasma homocysteine level and steepest keratometry (p = 0.004) and average Sim-K (p = 0.002).. The increased plasma level of homocysteine in keratoconus patients may either arise from a consequence of biochemical events such as oxidative stress, or it may contribute to the pathogenesis or progression of keratoconus by chelating copper, which is an important co-factor of lysyl oxidase enzyme taking place in corneal collagen crosslinking.

Topics: Folic Acid; Homocysteine; Humans; Keratoconus; Prospective Studies; Vitamin B 12