Evidence for the use of nutritional supplements and herbal medicines in common eye diseases

Prevalence of traditional eye medicine and self-treatment in Gurage Zone, Rural Ethiopia

INTRODUCTION

Traditional medicines are commonly used worldwide, especially in Africa-however, there is limited information on the prevalence and types of traditional eye medicine utilization in Ethiopia. The goal of this study was to determine the prevalence, the type and nature of traditional eye medicine use and practices related to self-medication for ophthalmic diseases in a rural Ethiopian population.

METHODS

A cross-sectional study was conducted in six randomly selected primary health centers in rural Gurage Zone, Southern Ethiopia. Health-seeking behavior, use of self-medication, and traditional eye medicine were assessed in the population using a semi-structured questionnaire. Descriptive statistics and multivariable logistic regression analysis were computed to determine associated factors for using self-medication and traditional eye medicine.

RESULT

Of the 814 participants interviewed, 487 (59.8%) reported using traditional eye medicine, mainly for combinations of symptoms of ocular redness, irritation, and eye discharge (95.5%). Besides, 604 (74.2%) participants reported self-treatment with tetracycline 1% eye ointment. Older age, females, low income, no formal education, and lack of access to media were risks for utilizing traditional eye medicine.

CONCLUSION

The use of traditional eye medicine and self-treatment are common in this population. Regulatory legislation, public awareness, and making eye care are vital activities required to monitor such practices.

The effects of probiotics supplements on metabolic indices and clinical signs in patients with diabetic retinopathy, a randomized double blind clinical trial

Purpose

This study was carried out to evaluate the effects of probiotics administration on clinical status and metabolic profiles in diabetic retinopathy (DR) patients.

Methods

This randomized, double-blind, placebo-controlled trial was conducted among 72 DR patients. Subjects received probiotics including Lactobacillus acidophilus, Bifidobacterium bifidum, Bifidobacterium langum, Bifidobacterium lactis daily (2 × 109 CFU/each strain) (n = 36) or placebo (starch) (n = 36) and were instructed to take one capsule daily for 12 weeks. Finally, 55 participants [probiotic group (n = 30) and placebo group (n = 25)] completed the study. Fasting blood samples were obtained at baseline and after the 12-week intervention to determine metabolic profiles. To determine the effects of probiotic supplementation on clinical symptoms and biochemical variables, we used one-way repeated measures analysis of variance.

Results

After the 12-week intervention, compared with the placebo, probiotic supplementation significantly decreased means serum insulin concentrations (Probiotic group: -4.9 ± 6.5vs. Placebo group: 3.0 ± 7.7 µIU/mL, Ptime×group<0.001), homeostatic model assessment for insulin resistance (Probiotic group: -2.5 ± 3.8 vs. Placebo group: 1.1 ± 2.7, Ptime×group<0.001) and hemoglobin A1c (HbA1C) (Probiotic group: -0.4 ± 0.7 vs. Placebo group: -0.02 ± 0.2%, Ptime×group=0.01), and significantly increased the quantitative insulin sensitivity check index (QUICKI) (Probiotic group: 0.02 ± 0.03 vs. Placebo group: -0.03 ± 0.04, Ptime×group<0.001). There was no significant effect of probiotic administration on other metabolic profiles and clinical symptoms.

Conclusions

Overall, probiotic supplementation after 12 weeks in DR patients had beneficial effects on few metabolic profiles. This study was registered under the Iranian website for clinical trials as http://www.irct.ir: IRCT20130211012438N29.

Review on the potential roles of traditional Chinese medicines in the prevention, treatment, and postoperative recovery of age-related cataract

ETHNIC PHARMACOLOGICAL RELEVANCE

Cataract is the most common cause of blindness worldwide, a visual disorder caused by a clouded lens that seriously affects People's Daily lives. Age-related cataract (ARC) is the most common type of cataract due to long-term combined effects of many factors, and its pathogenesis is varied. At present, the surgery is the main treatment for cataracts, but it is still limited to the prevention, treatment of early cataracts and the postoperative complications care. While, its drug treatments are still in the stage of exploration and research. Traditional Chinese Medicine (TCM), a unique resource in China, is conceived under the guidance of traditional Chinese medicine theory and has little toxicity and side effects, but it has made great progress in the treatment and prevention of ARC.

AIM OF THIS REVIEW

This review presents an overview of the pathogenesis of ARC in both traditional and modern medicines and summarizes the history and therapeutic effect of TCM on ARC including their formula, crude drugs and active components, and also the other auxiliary methods.

METHODS

A number of recognized databases like SciFinder, PubMed, Science Direct, Google Scholar, and China National Knowledge Infrastructure (CNKI) were extensively explored by using keywords and phrases such as "cataract", "age-related cataract", "traditional medicine", "ethnopharmacology", "herbs", "medicinal plants", or other relevant terms, and the plants/phytoconstituents that are evaluated in the models of age-related cataract. As well as the current TCM adjuvant therapy used in the clinical treatment were summarized.

RESULTS

TCM revealed to plays an active role in treating age-related cataract, via multi-pathway and multi-target, and can treat or delay ARC by inhibiting abnormal glucose metabolism, antioxidant damage, inhibiting LEC apoptosis, and so on, which is in concordance with the good effects of the global use of TCM in clinical application. Concerning the early prevention and treatment of cataract and postoperative complications, TCM and auxiliary methods remain to achieve better clinical effects.

CONCLUSION

ARC belongs to the category of "Yuan Yi Nei Zhang" in TCM theory, showing that there are many causes of ARC including aging, and kidney-yang, spleen, sperm and blood deficiencies. At the same time, the viscera gradually decline, as well as yin or yang progressively become weak, especially in the elder people. So, TCM could be mainly based on liver, kidney, and spleen syndrome differentiation, personalizing diagnosis and treatment, following multiple targets, regulating fundamentally yin and yang, and thus justifying the advantages of Chinese medicine in the prevention and treatment of ARC.

Complementary Approaches to Retinal Health Focusing on Diabetic Retinopathy

Diabetes mellitus affects carbohydrate homeostasis but also influences fat and protein metabolism. Due to ophthalmic complications, it is a leading cause of blindness worldwide. The molecular pathology reveals that nuclear factor kappa B (NFκB) has a central role in the progression of diabetic retinopathy, sharing this signaling pathway with another major retinal disorder, glaucoma. Therefore, new therapeutic approaches can be elaborated to decelerate the ever-emerging "epidemics" of diabetic retinopathy and glaucoma targeting this critical node. In our review, we emphasize the role of an improvement of lifestyle in its prevention as well as the use of phytomedicals associated with evidence-based protocols. A balanced personalized therapy requires an integrative approach to be more successful for prevention and early treatment.

The effect of GLP-1 receptor agonist lixisenatide on experimental diabetic retinopathy

AIMS

Glucagon-like peptide-1 receptor agonists are effective treatments for type 2 diabetes, effectively lowering glucose without weight gain and with low risk for hypoglycemia. However, their influence on the retinal neurovascular unit remains unclear. In this study, we analyzed the effects of the GLP-1 RA lixisenatide on diabetic retinopathy.

METHODS

Vasculo- and neuroprotective effects were assessed in experimental diabetic retinopathy and high glucose-cultivated C. elegans, respectively. In STZ-diabetic Wistar rats, acellular capillaries and pericytes (quantitative retinal morphometry), neuroretinal function (mfERG), macroglia (GFAP western blot) and microglia (immunohistochemistry) quantification, methylglyoxal (LC-MS/MS) and retinal gene expressions (RNA-sequencing) were determined. The antioxidant properties of lixisenatide were tested in C. elegans.

RESULTS

Lixisenatide had no effect on glucose metabolism. Lixisenatide preserved the retinal vasculature and neuroretinal function. The macro- and microglial activation was mitigated. Lixisenatide normalized some gene expression changes in diabetic animals to control levels. Ets2 was identified as a regulator of inflammatory genes. In C. elegans, lixisenatide showed the antioxidative property.

CONCLUSIONS

Our data suggest that lixisenatide has a protective effect on the diabetic retina, most likely due to a combination of neuroprotective, anti-inflammatory and antioxidative effects of lixisenatide on the neurovascular unit.

Restoring the oxidative balance in age-related diseases - An approach in glaucoma

As human life expectancy increases, age-related health issues including neurodegenerative diseases continue to rise. Regardless of genetic or environmental factors, many neurodegenerative conditions share common pathological mechanisms, such as oxidative stress, a hallmark of many age-related health burdens. In this review, we describe oxidative damage and mitochondrial dysfunction in glaucoma, an age-related neurodegenerative eye disease affecting 80 million people worldwide. We consider therapeutic approaches used to counteract oxidative stress in glaucoma, including untapped treatment options such as novel plant-derived antioxidant compounds that can reduce oxidative stress and prevent neuronal loss. We summarize the current pre-clinical models and clinical work exploring the therapeutic potential of a range of candidate plant-derived antioxidant compounds. Finally, we explore advances in drug delivery systems, particular those employing nanotechnology-based carriers which hold significant promise as a carrier for antioxidants to treat age-related disease, thus reviewing the key current state of all of the aspects required towards translation.

Carotenoids and Carcinogenesis: Exploring the Antioxidant and Cell Signaling Roles of Carotenoids in the Prevention of Cancer

Carotenoids are lipid soluble pigments found in various fruits and vegetables and are naturally produced in photoautotrophic plants. Various studies have investigated the properties of carotenoids to determine how they are able to mitigate numerous diseases, including cancer. Carotenoids present in human serum, including β-carotene, α-carotene, lycopene, β-cryptoxanthin, zeaxanthin, and lutein have demonstrated the ability to act as anticarcinogenic agents. Prevention of disease is often described to be more effective than treatment; as cancer impacts millions of lives globally, the role of carotenoids in the prevention of oncogenesis for numerous types of cancers have been extensively researched. This review provides an in-depth analysis of the structure and properties of carotenoids, as well as the identified and potential mechanisms by which carotenoids can act as a chemopreventative agent.

Insight into the potential application of polyphenol-rich dietary intervention in degenerative disease management

In recent times, a great number of plants have been studied in order to identify new components with nutraceutical properties, among which are polyphenols. Dietary polyphenols represent a large group of bioactive molecules widely found in the food of plant origin and they have been found able to prevent the onset and progression of degenerative diseases, and to reduce and control their symptoms. These health protective effects have been mainly related to their antioxidant and anti-inflammatory properties. However, it must be considered that the application of isolated polyphenols as nutraceuticals is quite limited due to their poor systemic distribution and relative bioavailability. The present review highlights the potential effect of dietary intervention with polyphenol-rich food and plant extracts in patients with cancer, diabetes and neurodegenerative, autoimmune, cardiovascular and ophthalmic diseases, as well as the possible molecular mechanisms of action suggested in numerous studies with animal models.

Natural Products: Evidence for Neuroprotection to Be Exploited in Glaucoma

Glaucoma, a leading cause of irreversible blindness worldwide, is an optic neuropathy characterized by the progressive death of retinal ganglion cells (RGCs). Elevated intraocular pressure (IOP) is recognized as the main risk factor. Despite effective IOP-lowering therapies, the disease progresses in a significant number of patients. Therefore, alternative IOP-independent strategies aiming at halting or delaying RGC degeneration is the current therapeutic challenge for glaucoma management. Here, we review the literature on the neuroprotective activities, and the underlying mechanisms, of natural compounds and dietary supplements in experimental and clinical glaucoma.

Effect of dietary modification and antioxidant supplementation on intraocular pressure and open-angle glaucoma

Primary open-angle glaucoma (POAG) is an age-dependent, intraocular pressure (IOP)-related degeneration of the retinal ganglion cells (RGC). At present, IOP is the only modifiable factor that has been identified to prevent glaucomatous vision loss. Though the pathogenesis of glaucomatous optic neuropathy is still not well understood, increasing evidence suggests oxidative stress may contribute to the induction and progression of glaucoma. Furthermore, antioxidant use may be protective against glaucoma through various mechanisms, including reducing IOP, preserving vascular health, and preventing ganglion cell loss. This article provides a comprehensive review of the effect of oxidative stress, diet, and antioxidant therapy on IOP and open-angle glaucoma.

Degradation and regulation of edible flower pigments under thermal processing: a review

More and more consumers are aware of the potential health benefits of edible flower pigments. With the increased popularity and broader application of edible flower pigments, their degradation under thermal processing has attracted researchers' attention, because this may affect the pigment functionalities. At high temperature of thermal processing, polyene pigments are easy to oxidize, degrade and isomerize due to high unsaturation, and phenolic pigments may hydrolyze and isomerize of glycosides, which will result in the decreased antioxidant activity and eating quality, and discounted potential health benefits. Therefore, it is very important to understand the degradation mechanisms of edible flower pigments under thermal processing, which is important to develop corresponding control methods to minimize such negative impacts. This review paper discussed the recent development in the degradation mechanisms and regulation methods of edible flower pigments under thermal processing.

Health Benefits of Polyphenols and Carotenoids in Age-Related Eye Diseases

Oxidative stress and inflammation play a critical role in the initiation and progression of age-related ocular abnormalities as cataract, glaucoma, diabetic retinopathy, and macular degeneration. Therefore, phytochemicals with proven antioxidant and anti-inflammatory activities, such as carotenoids and polyphenols, could be of benefit in these diseases. We searched PubMed and Web of Science databases for original studies investigating the benefits of different carotenoids and polyphenols in age-related ophthalmic diseases. Our results showed that several polyphenols (such as anthocyanins, Ginkgo biloba, quercetin, and resveratrol) and carotenoids (such as lutein, zeaxanthin, and mezoxanthin) have shown significant preventive and therapeutic benefits against the aforementioned conditions. The involved mechanisms in these findings include mitigating the production of reactive oxygen species, inhibiting the tumor necrosis factor-α and vascular endothelial growth factor pathways, suppressing p53-dependent apoptosis, and suppressing the production of inflammatory markers, such as interleukin- (IL-) 8, IL-6, IL-1a, and endothelial leucocyte adhesion molecule-1. Consumption of products containing these phytochemicals may be protective against these diseases; however, adequate human data are lacking. This review discusses the role and mechanisms of polyphenols and carotenoids and their possible synergistic effects on the prevention and treatment of age-related eye diseases that are induced or augmented by oxidative stress and inflammation.

Rational Basis for Nutraceuticals in the Treatment of Glaucoma

BACKGROUND

Glaucoma, the second leading cause of blindness worldwide, is a chronic optic neuropathy characterized by progressive retinal ganglion cell (RGC) axons degeneration and death. Primary open-angle glaucoma (OAG), the most common type, is often associated with increased intraocular pressure (IOP), however other factors have been recognized to partecipate to the patogenesis of the optic neuropathy. IOP-independent mechanisms that contribute to the glaucoma-related neurodegeneration include oxidative stress, excitotoxicity, neuroinflammation, and impaired ocular blood flow. The involvement of several and diverse factors is one of the reasons for the progression of glaucoma observed even under efficient IOP control with the currently available drugs.

METHODS

Current research and online content related to the potential of nutritional supplements for limiting retinal damage and improving RGC survival is reviewed.

RESULTS

Recent studies have suggested a link between dietary factors and glaucoma risk. Particularly, some nutrients have proven capable of lowering IOP, increase circulation to the optic nerve, modulate excitotoxicity and promote RGC survival. However, the lack of clinical trials limit their current therapeutic use. The appropriate use of nutraceuticals that may be able to modify the risk of glaucoma may provide insight into glaucoma pathogenesis and decrease the need for, and therefore the side effects from, conventional therapies.

CONCLUSION

The effects of nutrients with anti-oxidant and neuroprotective properties are of great interest and nutraceuticals may offer some therapeutic potential although a further rigorous evaluation of nutraceuticals in the treatment of glaucoma is needed to determine their safety and efficacy.

The use of orchids in Chinese medicine

In this article, the therapeutic uses of five Chinese medicines that contain orchids are discussed, together with a brief report of some of the animal experimentation undertaken. The impression that these preparations have no therapeutic use may be incorrect. However, herbal preparations have not usually been subject to the rigorous characterization and standardization necessary for clinical study, and persuading practitioners that substances in use for many centuries still need to be tested in randomized controlled clinical trials is proving a significant challenge.

Characterization of Emodin as a Therapeutic Agent for Diabetic Cataract

Aldose reductase (AR) in the lens plays an important role in the pathogenesis of diabetic cataract (DC) by contributing to osmotic and oxidative stress associated with accelerated glucose metabolism through the polyol pathway. Therefore, inhibition of AR in the lens may hold the key to prevent DC formation. Emodin, a bioactive compound isolated from plants, has been implicated as a therapy for diabetes. However, its inhibitory activity against AR remains unclear. Our results showed that emodin has good selectively inhibitory activity against AR (IC50 = 2.69 ± 0.90 μM) but not other aldo-keto reductases and is stable at 37 °C for at least 7 days. Enzyme kinetic studies demonstrated an uncompetitive inhibition against AR with a corresponding inhibition constant of 2.113 ± 0.095 μM. In in vivo studies, oral administration of emodin reduced the incidence and severity of morphological markers of cataract in lenses of AR transgenic mice. Computational modeling of the AR-NADP(+)-emodin ternary complex indicated that the 3-hydroxy group of emodin plays an essential role by interacting with Ser302 through hydrogen bonding in the specificity pocket of AR. All the findings above provide encouraging evidence for emodin as a potential therapeutic agent to prevent cataract in diabetic patients.

Anti-osmotic and antioxidant activities of gigantol from Dendrobium aurantiacum var. denneanum against cataractogenesis in galactosemic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Dendrobium aurantiacum var. denneanumis widespread in southern China, locally known as "Shihu", "Huangcao" or "Fengdou", has long been used in traditional Chinese medicine for antipyretic, immunomodulatory, anti-aging effects and eye benefiting.

AIM OF THIS STUDY

To investigate the effects of gigantol extracted from the stem of D. aurantiacum var. denneanum on the formation of galactose-induced cataractogenesis and the potential mechanisms underlying these effects.

MATERIALS AND METHODS

Cataract lens models were induced by d-galactose both in vitro and in vivo. The transparency of the rat lenses in vitro and in vivo was observed with an anatomical microscope and a slit lamp microscope. The differential protein and action targets of gigantol were determined and compared among the control group, model group, and gigantol group using two-dimensional electrophoresis and mass spectrometry (MS). Enzyme kinetics was used to show the ability of gigantol to respress aldose reductase (AR) and inducible nitric oxide synthase (iNOS). Quantitative real-time PCR (RT-qPCR). was used to detect repression of the expression of AR and iNOS genes. Molecular docking and dynamic simulation were used to predict the interaction points and combination patterns between gigantol, AR, and iNOS.

RESULTS

Gigantol was found to prevent galactose-induced damage to the rat lenses both in vitro and in vivo, to delay lens turbidity, and to keep the lenses transparent. Differential proteomes, MS, and RT-qPCR showed AR and iNOS to be the target proteins of gigantol. Gigantol reduced the galactose-induced AR and iNOS mRNA expression by 51.2% and 60.9%, respectively. The IC50 of gigantol for inhibition of AR and iNOS activities were 65.67 μg/mL and 8.768 μg/mL, respectively. Gigantol-AR binding sites were Trp111, His110, Tyr48, and Trp20, and gigantol-iNOS binding sites were Ile195 and Gln257. The main forms of interaction were hydrophobic forces, hydrogen bonds, and van der Waals forces.

CONCLUSION

Gigantol extracted from D. aurantiacum var. denneanum was found to inhibit galactose-induced formation of cataracts through repression of the gene expression and activity of AR and iNOS.

Preserving neural retina through re-emerging herbal interventions

Eye related diseases such as glaucoma, diabetic retinopathy, cataract, conjunctivitis are very common worldwide. With the current scenario India will be among the top five countries in the number of glaucoma cases. Limited discovery of successful drugs for the treatment of such diseases led scientists to look towards the use of conventional sources for treatment. Herbal extracts from Ayurveda have remained an important part of treatment regime in many parts of world even today. For this reason, local herbs possessing curative properties are still being used by local inhabitants due to its anti-inflammatory and antioxidant properties. Because retinal damage involves alterations in oxidative enzymes, blood flow changes and increase in apoptotic signals, herbal extracts are being tested for their ability to moderate antioxidant machinery and trigger neuroprotective pathways. The present review summarizes some of such herbal extracts which have been tested for their neuroprotective role in eye related diseases. The active components that exert neuroprotective effects have also been discussed along with possible mechanisms of action.

Dietary factors and the risk of glaucoma: a review

Glaucoma is an optic neuropathy characterized by a progressive typical pattern of optic neurodegeneration and visual field loss. A relatively high proportion of glauctomatous individuals admit to interest in dietary modification in an attempt to manage their disease. Heavy caffeine consumption appears to have a transient effect on increasing intraocular pressure (IOP). This effect may be clinically insignificant for nonglaucomatous individuals, but the association warrants clinical consideration in those with the disease. Studies investigating the relationship between self-reported antioxidant intake and risk of glaucomatous disease have reported conflicting results. Preliminary studies investigating the relationship between self-reported glaucoma diagnosis and consumption of the oxidants calcium and iron suggest a possible relationship indicating increased risk of the disease with increased consumption of these dietary factors. Initial reports in the literature suggest a potential role for dietary modification in the treatment of glaucomatous optic neuropathy. Further study, with randomized controlled trials, may be necessary to further characterize these relationships.

Antioxidants and diabetic retinopathy

The biochemical perturbations in diabetes mellitus (DM) create the conditions for the production of free radicals, the consequence of which is increased oxidative stress. Evidence has accrued over the past 2 decades that suggests that oxidative stress is an important pathogenetic factor in the development of diabetic retinopathy (DR). Experimental data show that the use of strategies that ameliorate oxidative stress can prevent and retard the development of DR in the animal model. Clinical observations also suggest that reducing oxidative stress may help to reverse pathological manifestations of DR. The present article constitutes an examination of the role of antioxidants in the management of DR and the current state of clinically relevant knowledge.

Flavonoid intake and eye health

In the modern era of evidence-based scientific medicine, there is little recognition of centuries of shaman observational evidence. Yet it is extremely difficult to conduct long duration controlled studies of large populations. The controversy surrounding the issue of flavonoid bioactivity and alleged benefits for eye health is also plagued by natural product industry marketing efforts that rely on small, often poorly designed studies. Ample laboratory evidence exists from in vitro and in vivo studies that provide plausible mechanistic evidence for flavonoid interactions relevant to visual function. Lacking are large randomized double-blind placebo-controlled studies in older subjects who have early signs of vision impairment. These studies could link flavonoid intake and bioavailability to efficacy in prevention of age related vision disorders that develop over decades. Support for clinical trials remains to be found before a full "recommendation" can be made regarding the value of diets high in flavonoids for eye health.

Modulation of diabetic retinopathy pathophysiology by natural medicines through PPAR-γ-related pharmacology

Diabetic retinopathy (DR) is one of the most common microvascular complications of diabetes and remains a major cause of preventable blindness among adults at working age. DR involves an abnormal pathology of major retinal cells, including retinal pigment epithelium, microaneurysms, inter-retinal oedema, haemorrhage, exudates (hard exudates) and intraocular neovascularization. The biochemical mechanisms associated with hyperglycaemic-induced DR are through multifactorial processes. Peroxisome proliferator-activated receptor-γ (PPAR-γ) plays an important role in the pathogenesis of DR by inhibiting diabetes-induced retinal leukostasis and leakage. Despite DR causing eventual blindness, only a few visual or ophthalmic symptoms are observed until visual loss develops. Therefore, early medical interventions and prevention are the current management strategies. Laser photocoagulation therapy is the most common treatment. However, this therapy may cause retinal damage and scarring. Herbal and traditional natural medicines may provide an alternative to prevent or delay the progression of DR. This review provides an analysis of the therapeutic potential of herbal and traditional natural medicines or their active components for the slowdown of progression of DR and their possible mechanism through the PPAR-γ pathway.

Nutrient intake and risk of open-angle glaucoma: the Rotterdam Study

Open-angle glaucoma (OAG) is the commonest cause of irreversible blindness worldwide. Apart from an increased intraocular pressure (IOP), oxidative stress and an impaired ocular blood flow are supposed to contribute to OAG. The aim of this study was to determine whether the dietary intake of nutrients that either have anti-oxidative properties (carotenoids, vitamins, and flavonoids) or influence the blood flow (omega fatty acids and magnesium) is associated with incident OAG. We investigated this in a prospective population-based cohort, the Rotterdam Study. A total of 3502 participants aged 55 years and older for whom dietary data at baseline and ophthalmic data at baseline and follow-up were available and who did not have OAG at baseline were included. The ophthalmic examinations comprised measurements of the IOP and perimetry; dietary intake of nutrients was assessed by validated questionnaires and adjusted for energy intake. Cox proportional hazard regression analysis was applied to calculate hazard ratios of associations between the baseline intake of nutrients and incident OAG, adjusted for age, gender, IOP, IOP-lowering treatment, and body mass index. During an average follow-up of 9.7 years, 91 participants (2.6%) developed OAG. The hazard ratio for retinol equivalents (highest versus lowest tertile) was 0.45 (95% confidence interval 0.23–0.90), for vitamin B1 0.50 (0.25–0.98), and for magnesium 2.25 (1.16–4.38). The effects were stronger after the exclusion of participants taking supplements. Hence, a low intake of retinol equivalents and vitamin B1 (in line with hypothesis) and a high intake of magnesium (less unambiguous to interpret) appear to be associated with an increased risk of OAG.

Traditional eye medicine use by newly presenting ophthalmic patients to a teaching hospital in south-eastern Nigeria: socio-demographic and clinical correlates

BACKGROUND

This study set out to determine the incidence, socio-demographic, and clinical correlates of Traditional Eye Medicine (TEM) use in a population of newly presenting ophthalmic outpatients attending a tertiary eye care centre in south-eastern Nigeria.

METHODS

In a comparative cross-sectional survey at the eye clinic of the University of Nigeria Teaching Hospital (UNTH), Enugu, between August 2004 - July 2006, all newly presenting ophthalmic outpatients were recruited. Participants' socio-demographic and clinical data and profile of TEM use were obtained from history and examination of each participant and entered into a pretested questionnaire and proforma. Participants were subsequently categorized into TEM- users and non-users; intra-group analysis yielded proportions, frequencies, and percentages while chi-square test was used for inter-group comparisons at P = 0.01, df = 1.

RESULTS

Of the 2,542 (males, 48.1%; females, 51.9%) participants, 149 (5.9%) (males, 45%; females, 55%) used TEM for their current eye disease. The TEMs used were chemical substances (57.7%), plant products (37.7%), and animal products (4.7%). They were more often prescribed by non-traditional (66.4%) than traditional (36.9%) medicine practitioners. TEMs were used on account of vision loss (58.5%), ocular itching (25.4%) and eye discharge (3.8%). Reported efficacy from previous users (67.1%) and belief in potency (28.2%) were the main reasons for using TEM. Civil servants (20.1%), farmers (17.7%), and traders (14.1%) were the leading users of TEM. TEM use was significantly associated with younger age (p < 0.01), being married (p < 0.01), rural residence (p < 0.01), ocular anterior segment disease (p < 0.01), delayed presentation (p < 0.01), low presenting visual acuity (p < 0.01), and co-morbid chronic medical disease (p < 0.01), but not with gender (p = 0.157), and educational status (p = 0.115).

CONCLUSION

The incidence of TEM use among new ophthalmic outpatients at UNTH is low. The reasons for TEM use are amenable to positive change through enhanced delivery of promotive, preventive, and curative public eye care services. This has implications for eye care planners and implementers. To reverse the trend, we suggest strengthening of eye care programmes, even distribution of eye care resources, active collaboration with orthodox eye care providers and traditional medical practitioners, and intensification of research efforts into the pharmacology of TEMs.

Reduced-serum vitamin C and increased uric acid levels in normal-tension glaucoma

BACKGROUND

Vitamin A, B(9), C, E, and uric acid are well-known antioxidants and may prevent age-related eye disorders. The aim of the present study was to investigate the levels of antioxidant vitamins, A, B(9), C, E, and antioxidative substance, uric acid in the serum of Japanese patients with normal-tension glaucoma and compare the results with normal controls.

METHODS

All subjects with suspicion of primary open-angle glaucoma who came to the glaucoma subspeciality clinic of Keio University Hospital were enrolled in this study. Sixty patients (28 males, 32 females; mean age +/- standard deviation: 59.9 +/- 9.8 years) with newly diagnosed primary open-angle glaucoma patients were consecutively enrolled in this study. After the diagnosis of primary open-angle glaucoma, the patients underwent 24-h IOP measurements. Forty-seven newly diagnosed consecutive normal-tension glaucoma patients (18 males, 29 females; mean age +/- standard deviation: 59.5 +/- 10.2 years) were enrolled in this study. The control subjects were recruited from subjects who came to the clinic for annual refractive check-up. The 44 consecutive control subjects of the current study, (16 males, 28 females; 62.7 +/- 14.8 years) did not have any ocular diseases. The serum levels of vitamins A, B(9), C, E, and uric acid were measured. The values were compared between the normal-tension glaucoma and control groups by the Mann-Whitney U test.

RESULTS

Serum levels of vitamin C were significantly lower in normal-tension glaucoma patients than in normal healthy controls (P = 0.04; normal-tension glaucoma; 4.6 +/- 4.0 microg/ml control; 6.3 +/- 3.9 microg/ml). Uric acid level was significantly higher in normal-tension glaucoma patients than in controls (P = 0.01; normal-tension glaucoma; 5.8 +/- 1.5 mg/dl control; 4.9 +/- 1.4 mg/dl). No statistically significant difference was seen in vitamin A (P = 0.41; normal-tension glaucoma; 82.1 +/- 26.7 microg/dl control; 77.1 +/- 30.1 microg/dl), B(9) (P = 0.37; normal-tension glaucoma; 8.7 +/- 4.3 ng/ml control; 8.0 +/- 3.1 ng/ml)and E (P = 0.83; normal-tension glaucoma; 1.5 +/- 0.6 control; 1.5 +/- 0.6) levels between normal-tension glaucoma and control groups.

CONCLUSION

Normal-tension glaucoma patients had lower serum levels of vitamin C and increased levels of uric acid. These observations may pave the way for possible alternative treatment for normal-tension glaucoma.

Biological diversity, dietary diversity, and eye health in developing country populations: establishing the evidence-base

Human and ecosystem health converge around biological diversity issues. Cultivated and wild plants as food and medicine make essential contributions to human health, which in turn provides rationales for conservation. While wild and cultivated plant diversity reasonably facilitates dietary diversity and positive health outcomes, the challenges of demonstrating this relationship limit its impact in concept, policy, and practice. We present a rationale for testing the dietary contribution of biological diversity to improved eye health as a case study based on existing phytochemical, pharmacological, and clinical knowledge. We consider the empirical evidence needed to substantiate, interpret, and apply this relationship at a population and ecosystem level within a unified research framework. Epidemiological data strongly support the prevention of childhood vitamin A deficiency blindness, cataract, and age-related macular degeneration by fruit and vegetable consumption. Phytonutrients, including the carotenoids lutein and zeaxanthin, protect the eye from oxidative stress and harmful light exposure. Laboratory, community, and population level research should prioritize food composition of dietary plants from both agriculture and the wild. Intervention studies, focus groups, and transmission of knowledge of local species and varieties within communities will further interpretation of epidemiological data. Population-based studies combining clinical data and measures of access and consumption of biological diversity are key to demonstrating the important relationships among biodiversity, dietary diversity, and health outcomes.

Glaucoma risk and the consumption of fruits and vegetables among older women in the study of osteoporotic fractures

PURPOSE

To explore the association between the consumption of fruits and vegetables and the presence of glaucoma.

DESIGN

Cross-sectional cohort study.

METHODS

In a sample of 1,155 women located in multiple centers in the United States, glaucoma specialists diagnosed glaucoma in at least one eye by assessing optic nerve head photographs and 76-point suprathreshold screening visual fields. Consumption of fruits and vegetables was assessed using the Block Food Frequency Questionnaire. The relationship between selected fruit and vegetable consumption and glaucoma was investigated using adjusted logistic regression models.

RESULTS

Among 1,155 women, 95 (8.2%) were diagnosed with glaucoma. In adjusted analysis, the odds of glaucoma risk were decreased by 69% (odds ratio [OR], 0.31; 95% confidence interval [CI], 0.11 to 0.91) in women who consumed at least one serving per month of green collards and kale compared with those who consumed fewer than one serving per month, by 64% (OR, 0.36; 95% CI, 0.17 to 0.77) in women who consumed more than two servings per week of carrots compared with those who consumed fewer than one serving per week, and by 47% (OR, 0.53; 95% CI, 0.29 to 0.97) in women who consumed at least one serving per week of canned or dried peaches compared with those who consumed fewer than one serving per month.

CONCLUSIONS

A higher intake of certain fruits and vegetables may be associated with a decreased risk of glaucoma. More studies are needed to investigate this relationship.

The use of orchids in Chinese medicine

In this article, the therapeutic uses of five Chinese medicines that contain orchids are discussed, together with a brief report of some of the animal experimentation undertaken. The impression that these preparations have no therapeutic use may be incorrect. However, herbal preparations have not usually been subject to the rigorous characterization and standardization necessary for clinical study, and persuading practitioners that substances in use for many centuries still need to be tested in randomized controlled clinical trials is proving a significant challenge.

Supplements and age-related eye conditions the beaver dam eye study

OBJECTIVE

To investigate the association of use of vitamin, mineral, and nonvitamin nonmineral supplements with common age-related eye diseases.

DESIGN

Population-based prospective study with incidence data.

PARTICIPANTS

Subjects were participants in the Beaver Dam Eye Study who contributed data in 1988 to 1990 (n = 4926), 1993 to 1995 (n = 3722), 1998 to 2000 (n = 2962), and 2003 to 2005 (n = 2375).

METHODS

Use of all medications and supplements were collected from study participants at each of 4 examinations. Intraocular pressure (IOP) measurement and fundus and lens photography were done at each visit. Visual field data are available only from baseline. Photographs of the lenses, retina, and discs were graded using standard protocols by trained graders.

MAIN OUTCOME MEASURES

Incidence of age-related cataracts, macular degeneration (AMD), and high IOP for one set of analyses and incidence of supplement use for the second set of analyses.

RESULTS

There was little evidence of any significant associations between supplement use and incident ocular outcomes except for a small protective effect for cortical cataracts by vitamins A and D, zinc, and multivitamins and increased odds of late AMD. Late AMD was associated with incident use of vitamins A, C, and E and zinc.

CONCLUSIONS

Age-related macular degeneration seems to precede use of vitamins A, C, and E and zinc. This may reflect advice by family, friends, and health care providers about the benefits of Age-Related Eye Disease Study-like supplements.

Macular degeneration

Macular degeneration is a term that describes a large group of conditions that are collectively the most common cause of irreversible vision loss in the developed world. Approximately one in three people will be affected to some degree by the time they reach 75 years of age. Many forms of macular degeneration have a significant genetic component, and a large amount of progress has recently been made in understanding the genes involved. In the future, genetic testing may allow specific preventive treatments to be delivered to individuals at risk, decades before the disease would ordinarily become manifest.