Increased expression of oxyproteins in the optic nerve head of an in vivo model of optic nerve ischemia

Co-occurrence of chronic kidney disease and glaucoma: Epidemiology and etiological mechanisms

As the histology, physiology, and pathophysiology of eyes and kidneys show substantial overlap, it has been suggested that eye and kidney diseases, such as glaucoma and chronic kidney disease (CKD), may be closely interlinked. We review the relationship between CKD and various subtypes of glaucoma, including primary open-angle glaucoma, primary angle- closure glaucoma, normal tension glaucoma, pseudoexfoliation syndrome, and several glaucoma endophenotypes. We also discuss the underlying pathogenic mechanisms and common risk factors for CKD and glaucoma, including atherosclerosis, the renin-angiotensin system, genes and genetic polymorphisms, vitamin D deficiency, and erythropoietin. The prevalence of glaucoma appears elevated in CKD patients, and vice versa, and the literature points to many intriguing associations; however, the associations are not always confirmed, and sometimes apparently opposite observations are reported. Glaucoma and CKD are complex diseases, and their mutual influence is only partially understood.

Role of Oxidative Stress in Ocular Diseases Associated with Retinal Ganglion Cells Degeneration

Ocular diseases associated with retinal ganglion cell (RGC) degeneration is the most common neurodegenerative disorder that causes irreversible blindness worldwide. It is characterized by visual field defects and progressive optic nerve atrophy. The underlying pathophysiology and mechanisms of RGC degeneration in several ocular diseases remain largely unknown. RGCs are a population of central nervous system neurons, with their soma located in the retina and long axons that extend through the optic nerve to form distal terminals and connections in the brain. Because of this unique cytoarchitecture and highly compartmentalized energy demand, RGCs are highly mitochondrial-dependent for adenosine triphosphate (ATP) production. Recently, oxidative stress and mitochondrial dysfunction have been found to be the principal mechanisms in RGC degeneration as well as in other neurodegenerative disorders. Here, we review the role of oxidative stress in several ocular diseases associated with RGC degenerations, including glaucoma, hereditary optic atrophy, inflammatory optic neuritis, ischemic optic neuropathy, traumatic optic neuropathy, and drug toxicity. We also review experimental approaches using cell and animal models for research on the underlying mechanisms of RGC degeneration. Lastly, we discuss the application of antioxidants as a potential future therapy for the ocular diseases associated with RGC degenerations.

Systemic oxidative stress in non-arteritic anterior ischemic optic neuropathy

PURPOSE

To investigate whether the serum total oxidant status (TOS), total antioxidant status (TAS), advanced oxidation protein products (AOPP), and thiol parameters could play a role in the pathogenesis of non-arteritic anterior ischemic optic neuropathy (NA-AION).

METHODS

In this study, 18 newly diagnosed NA-AION patients and 17 healthy subjects (control group) were included. Serum plasma TOS and TAS, AOPP, and thiol parameters were measured by spectrophotometric method and the results were compared.

RESULTS

Mean age of the patients and the controls were 60.8 ± 8.4 and 61.9 ± 9.4 years, respectively (p = 0.729). There were no significant differences between the patients and the control group with regard to the values of TAS, TOS, AOPP, and thiol (p = 0.869, p = 0.863, p = 0.040, p = 0.314; respectively). There was a positive correlation between TOS and thiol (p = 0.002, r = 0.681).

CONCLUSION

We found no significant relationship between systemic oxidative parameters and NA-AION. However, this study should be accepted as a pilot investigation and needs to be validated.

The Relationship between Vitamin D and Glaucoma: A Kangbuk Samsung Health Study

PURPOSE

To investigate the relationship between vitamin D and glaucoma.

METHODS

This retrospective, cross-sectional study included subjects who underwent a health screening at the Health Screening Center of Kangbuk Samsung Hospital from August 2012 to July 2013. All fundus photographs were reviewed by ophthalmologists. The ophthalmologists determined if an eye was glaucomatous based on the criteria set forth by the International Society of Geographical and Epidemiological Ophthalmology and by the appearance of the retinal nerve fiber layer and optic disc. If the subjects previously underwent an ophthalmologic examination, they were enrolled based on the documented history. In addition to fundus photographs, each participant underwent a systemic examination including blood sampling and sociodemographic and behavioral questionnaires. The subjects were divided into five groups according to serum 25-hydroxyvitamin D (25(OH)D) level. Multivariate logistic regression models were constructed to assess possible associations between elevated glaucoma risk and systemic factors with a p < 0.2 on univariate analysis.

RESULTS

Of the 169,208 subjects older than 20 years, 123,331 were eligible for the study. There was no difference in the prevalence of glaucoma according to quintile of serum 25(OH)D level based on sex (p = 0.412 for males, p = 0.169 for females). According to the multivariable-adjusted logistic analysis, the odds ratio of glaucoma for the fourth quintile was significantly lower than that of the first quintile in females (odds ratio, 0.713; 95% confidence interval, 0.520 to 0.979).

CONCLUSIONS

Lower 25(OH)D level was significantly associated with an elevated risk of glaucoma in females compared with higher 25(OH)D level. Further evaluation is needed to investigate the relationship between glaucoma and vitamin D.