Blood thiamine pyrophosphate concentration and its correlation with the stage of diabetic retinopathy.

PURPOSE: To assess the possible relationship between blood thiamine pyrophosphate (TPP) concentration and stage of diabetic retinopathy (DR). METHODS: This comparative cross-sectional study included 80 patients with type 2 diabetes mellitus (T2DM) and 20 age- and gender-matched healthy controls. Diabetic patients were subclassified into four groups each consisting of 20 subjects: no DR, mild-moderate non-proliferative DR (mild-moderate NPDR), severe NPDR, and proliferative DR (PDR). Blood TPP concentration was assessed with high-performance liquid chromatography (HPLC) assay and was correlated with the stage of DR. RESULTS: Mean blood TPP concentration was 80.2 ± 14.8 nmol/L in control group. It was, respectively, 69.85 ± 18.1, 64.95 ± 13.4, 61.9 ± 13.4 and 60.75 ± 14.3 nmol/L in no DR, mild-moderate NPDR, severe NPDR and PDR groups. For mild-moderate NPDR, severe NPDR and PDR groups, TPP concentrations were significantly lower compared with controls (p: 0.014, 0.002, 0.001, respectively). Mean TPP concentration for NPDR patients was higher than for PDR patients, but the difference was not significant (p: 0.478). ANOVA revealed a significant difference between TPP concentrations of groups (p: 0.001). Mean TPP concentration decreased with the stage of DR, and number of patients with thiamine deficiency increased gradually with the stage of DR. A negative correlation was found between the TPP level and occurrence of DR (p: 0.000). CONCLUSION: The results suggest that lower blood TPP concentrations were associated with higher risk of DR. Thiamine might play an important role in the pathophysiology and progression of DR. Thiamine and its derivatives might represent an approach to the prevention and/or treatment of early DR.

Phacoemulsification and Core Vitrectomy in Fuchs' Heterochromic Uveitis.

OBJECTIVE: To evaluate the efficacy of phacoemulsification combined with posterior capsulorhexis, core vitrectomy and ciliary sulcus intraocular lens (IOL) implantation in patients with Fuchs' heterochromic uveitis (FHU). MATERIALS AND METHODS: A total of 18 eyes of 18 patients with FHU underwent cataract surgery were included in the study. 18 eyes with FHU underwent posterior capsulorhexis, core vitrectomy and poly (methyl methacrylate) (PMMA) IOL implantation in the ciliary sulcus. Subjects were chosen for this procedure based on an intraoperative vitreous haziness assessment, performed by indirect ophthalmoscopy. Patients with +2 or more vitreous haziness qualified for this procedure. RESULTS: Of the 83 eyes with FHU that underwent cataract surgery, 18 eyes (21.6%) of 18 patients were employed in the study. There were 11 (61.1%) men and 7 (38.9%) women in the study; ages ranged from 23 to 47, with a mean of 32.06 years. Follow-up ranged from 8 months to 49 months. There were no intraoperative complications except for peripheral iris bleeding in 7 eyes. There was no severe intraocular inflammation in any patient postoperatively. All patients had 0.05 or better logMAR visual acuity after corneal suture removal. Glaucoma developed in 2 patients. For the short term period, the main vision threatening problem was suture-induced astigmatism. CONCLUSION: Cataract surgery combined with posterior capsulorhexis, core vitrectomy and IOL implantation in the ciliary sulcus is safe and leads to good visual outcome due to the removal of the hazy vitreous in patients with FHU.

Evaluation of cardiovascular biomarkers in patients with age-related wet macular degeneration.

AIM: To evaluate levels of homocysteine, asymmetric dimethylarginine (ADMA), and nitric oxide (NO), as well as activity of endothelial NO synthase (eNOS), in patients with age-related macular degeneration (AMD). METHODS: The levels of homocysteine, ADMA, and NO and activity of eNOS in patients who were diagnosed with wet AMD by fundus fluorescein angiography (n=30) were compared to a control group with no retinal pathology (n=30). RESULTS: Levels of homocysteine and ADMA were found to be significantly higher in the wet AMD group than in the control group (P<0.001), whereas NO levels and eNOS activity were higher in the control group (P<0.001). In the wet AMD group, we detected a 2.64- and 0.33-fold increase in the levels of ADMA and homocysteine, respectively, and a 0.49- and 2.41-fold decrease in the eNOS activity and NO level, respectively. CONCLUSION: Elevated levels of homocysteine and ADMA were observed in patients with wet AMD. Increased ADMA may be responsible for the diminished eNOS activity found in these patients, which in turn contributes to the decrease in NO levels, which likely plays a role in the pathogenesis of AMD.