Mitigation of cataractogenic potential of cyanide by antioxidant vitamin administration

The effect of antioxidant vitamin (AOV) administration on cyanide-induced ocular damage was investigated in New Zealand White rabbits maintained for 30 days on either pure growers mash or mash + 400ppm cyanide with or without oral AOVs. Cyanide caused significant decreases in superoxide dismutase, catalase and Na+-K+ ATPase; and significant increases in malondialdehyde levels in the lens (p < 0.05). AOVs reversed the elevation in malondialdehyde but had no effect on the enzymes. The results suggest that the damaging effects of oxidative stress imposed by cyanide on the lens can be mitigated by AOVs, probably through enhancement of its antioxidant status rather than directly reversing the inhibition of SOD and catalase. This underscores the need for AOV supplements especially by individuals routinely exposed to habitual, dietary and occupational cyanide

Prevalence of corneal ulcer among contact lens wearers in Nigeria

Corneal Ulceration has been described as the most serious complication of contact lens wear worldwide. The incidence of corneal ulceration in contact lens wearers in Nigeria was determined retrospectively. 1759 case notes of patients who had worn contact lenses for at least one year were obtained from eye clinics in Lagos, Abuja and Port Harcourt. The incidence of corneal ulcer was 1.36 per 100 wearers over the 5-year period (January 1994 –December 1998), with an annual incidence of 0.27 per 100 wearer. Disposable extended wear soft lenses had the highest incidence of 2.94 per 100 closely followed by rigid gas permeable lenses 2.86 per 100. There were no corneal ulcers among conventional daily wear soft lens users. Males showed more cases of corneal ulceration 1.63% than females 1.24% and the age group of 10-19 years had the highest rate of corneal ulcerations (1.66%). It is therefore important for contact lens practitioners to encourage patients to comply with their lens case regimen or switch to daily wear lenses. Key Words: Contact lenses, Corneal ulcers, Lens type, Age. Global Jnl Medical Sciences Vol.2(2) 2003: 127-13

Pharmacological effect of tropical Vitamin A ointment and pothalmic Vitamin A solution in chemically induced corneal ulceration

No Abstract

Vitamin A ststus assessment of cataract and non-cataract elderly patients in midwestern (Edo and Delta States) Nigeria

No Abstract

The risks of external oculotoxicity in the usage of hydroquinone containing, cosmetic products (A case study of Warri, Del Ta State, Nigeria)

Hydroquinone, (benzene-1, 4-diol) belongs to the quinol group of compounds which are derivatives of phenols known to possess hypopigmentary effects on the skin. Among the dark skinned, it is described as a skin lightening substance when added to creams, soaps, lotions, gels and ointments. To look fair skinned has been the fancy and attraction of some female and male blacks whose major motive is for social (aesthetic) reasons so as to obtain a sense of distinction from their dark skinned contemporaries. The adverse effects of hydroquinone abuse have been of great concern to the government and people of Nigeria and the outcomes of such abuse range from skin cancers to toxicity of the external adnexia. Clinical eye examinations and questionnaires were used to investigate the oculo-toxic effects of hydroquinone among 200 respondents using hydroquinone containing products (Group A), compared to a control of 200 not using hydroquinone containing products (Group B), all residing in Warri, Delta State, Nigeria. Oculovisual disorders namely redness and itching, itching alone, redness alone and blurred vision occurred in 65% of the experimental group (group A) compared to 35% in control (group B). Among the experimental group, red eye and itching (120 respondents) followed by itching alone (90), red eye alone (47) and blurred vision (40) were the common signs and symptoms. In addition, 25% became exposed to hydroquinone-containing products through personal knowledge while (65%) were through encouragement by friends and relations and 3.0% through the prescription of dermatologists. The results indicate that there are indeed adverse oculotoxic effects of hydroquinone abuse in Nigeria.Keywords: hydroquinone, abuse, adverse effects, eyeWest African Journal of Pharmacology and Drug Research Vol. 20(1&2) 2005: 62-6

ASSESSMENT OF PLASMA ZINC STATUS OF SENILE CATARACT AND NON-CATARACT ELDERLY PATIENTS IN MID-WESTERN NIGERIA- A CASE STUDYOF EDO AND DELTA STATES OF NIGERIA

Cataract is the opacification of the crystalline lens, which may result in visual impairment and subsequent blindness. Incidence of cataract is distinctively more in tropical/ developing countries where pronounced exposure to sunlight and profound nutritional deficiencies are prevailing. Zinc is a trace element essential in human nutrition, ubiquitous in cells, significant in membrane function and cellular metabolism like protection of lens from oxidative damage and photochemistry of vision. Deficiency of zinc may be due to decreased intake, metabolic disorders, poor absorption and medication and may result in prolonged dark adaptation time, night blindness, retinal degenerations and cataract. The aim of this study was to assess the level of zinc in cataract and non-cataract elderly patients in Nigeria . Five hundred senile cataract and five hundred non-cataract respondents (males and females), ³ 60 years, without any other underlying factor that may cause visual impairment, were randomly (simple) selected among patients attending eye clinics of the teaching hospitals in Irrua and Benin City and general hospital Sapele. Blood samples were assessed by computerized atomic absorption spectroscopy and questionnaires were used to estimate dietary pattern (Modified Helen Keller International food frequency method). Using a baseline of plasma zinc levels < 1,050 mg/L, 38% of cataract and 17% of non-cataract respondents had deficient zinc status while the questionnaire showed 48% cataract and 21% non-cataract patients had reduced dietary zinc intake; with all the zinc deficient patients complaining of prolonged dark adaptation and night blindness. Physiological, biochemical and dietary parameters influence zinc status in the elderly which severally affect vitamin A metabolism with regard to absorption, and transportation. Majority of respondents with deficient zinc status suffered night blindness, which may occur in zinc deficiency even with normal vitamin A status. Zinc deficiency may, therefore, be implicated in the high prevalence of cataract manifestation in developing countries. Additionally, zinc deficiency may contribute to the high incidence of night blindness usually involved in vitamin A deficiency (VAD) in areas with high prevalence of VAD. KEY WORDS: Cataract, Zinc, Nutritional Status, Eye ETUDE DU PLASMA DE ZINC DANS LA SITUATION DE CATARACTE ET NON-CATARACTE SENILE CHEZ LES MALADES ASSEZ AGES DANS LE MIDWEST DU NIGERIA – UNE ETUDE DE CAS DES ETATS DE EDO ET DU DELTA DU NIGERIA. NOTE DE SYNTHESE La cataracte représente une opacification du cristallin qui peut donner lieu à un affaiblissement visuel et plus tard à la cécité. L\'incidence de la cataracte est typiquement plus fréquente dans les pays tropicaux/en voie de développement où prévaut une exposition marquée à la lumière solaire ainsi que des déficiences nutritionnelles profondes. Le zinc est un oligo-élément essentiel dans l\'alimentation humaine, omniprésent dans les cellules, important dans la fonction des membranes et du métabolisme cellulaire tels que la protection des lentilles cristallines contre les dégâts d\'oxydation et la photochimie de la vision. La déficience en zinc peut être due à une faible ingestion, des troubles métaboliques, une mauvaise absorption et une médication. Elle peut se traduire par l\'adaptation prolongée à l\'obscurité, la cécité de nuit, la dégénération de la rétine ainsi que la cataracte. La présente étude a pour objet d\'évaluer le niveau de zinc chez les malades assez âgés de cataracte et de non-cataracte du Nigeria qui ne présentent aucun autre facteur fondamental qui peut causer un affaiblissement visuel. Un échantillon aléatoire (simple) de cinq cents cas de cataracte sénile et de cinq cents cas de non-cataracte (hommes et femmes), âgés de plus de ³ 60 ans. Ces personnes ont été sélectionnées parmi les malades en consultations ophtalmologiques des hôpitaux universitaires de Irrua et Benin City et de l\'hôpital général de Sapele. Des échantillons de sang ont été analysés par la spectroscopie informatisée d\'absorption atomique. En outre, des questionnaires ont été utilisés pour étudier le modèle diététique (Méthode modifiée de la fréquence alimentaire de Helen Keller International). En utilisant des points de comparaison dont les niveaux de plasma de zinc sont < 1,050 mg/L, 38% des personnes interrogées à cataracte et 17% de celles qui n\'ont pas de cataracte ont une déficience en zinc. D\'autre part, le questionnaire a révélé que 48% de cas de cataracte et 21% de cas non-cataracte avaient diminué la quantité de zinc absorbée dans la nourriture. La plupart des malades ayant une déficience en zinc se plaignent d\'une adaptation prolongée à l\'obscurité et d\'une cécité de nuit. Les paramètres physiologiques, biochimiques et diététiques chez les personnes assez âgées influencent la condition par rapport au zinc qui affecte sévèrement le métabolisme de la vitamine A, à savoir l\'absorption et le transport. La plupart des personnes interrogées qui ont une déficience en zinc souffrent de cécité nocturne, qui peut apparaître à cause de la déficience en zinc même lorsque le niveau de vitamine A est normal. Le manque de zinc peut par conséquent compromettre le niveau élevé des cas de cataracte dans les pays en voie de développement. En outre, la déficience en zinc peut contribuer à une incidence élevée de cécité nocturne, souvent impliquée dans la déficience de la vitamine A (DVA) dans les régions à haute prévalence de DVA. Mots-clés :: Cataracte, Zinc, Condition nutritionnelle, Œil) AJFAND Vol.4(2) 200

Evaluation of Phytochemical Constituents, Antibacterial Activities and Effect of Exudate of Pycanthus Angolensis Weld Warb (Myristicaceae) on Corneal Ulcers in Rabbits

Purpose: A 1: 1: 2 mixture of exudates of Anchomonas difformis, Cyrtrospherma senegalense and Pycanthus Angolensis is claimed to be used for the treatment of corneal ulcers. The purpose of the study is to evaluate the phytochemical constituents, antibacterial activities and the effectiveness of a mixture of these exudates in the treatment of corneal ulcers as claimed in Traditional medicine practice. Method: Fresh exudates were collected in different containers. They were reduced to dryness and each residue tested for phytochemical constituents. Exudates of P. angolensis was further tested for antimicrobial activities and its effect on chemical - induced corneal ulcers in rabbits. Result: Only reducing sugars were detected in exudates of A. angolensis and C. senegalensis. Bioactive constituents detected in exudates of P. angolensis were the reducing sugars and phenolic compounds- tannins and flavonoids. This also showed antimicrobial activity against the organisms used. It healed the NaOH - induced corneal ulcers in rabbits within ten of days of treatment. Conclusion: Exudates of P.angolensis contained bioactive constituents and exhibited antibacterial activity, and healed the corneal ulcers induced in rabbits. Its use in traditional practice for healing corneal ulcers is rational, even in the absence of exudates of A. angolensis and C. senegalensis

The pharmacological effect of leaf extracts of Pillostigma thinningii(Schum) on chemically induced and bacterially infected corneal ulceration of Rabbit eyes

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Effect of Orally Administered Zingiber Officinale on the Intra Ocular Pressure of Experimental Rabbits

PURPOSE: To determine the therapeutic effect of Ginger (Zingiber officinale) on increased intraocular pressure (IOP). METHODS: Twenty male and female New Zealand rabbits divided into 5 groups (A, B, C, D and E) were used. Groups B and D were administered with topical atropine 1% for 2 weeks while groups A and C were not so treated and group E was used as control. After increased IOP was achieved in groups B and D, oral ginger (1.00 ml) obtained by hot (100 oC) extraction was administered to each rabbit in groups A and B while 1.0 ml of cold (37 oC) extracts of ginger was administered to groups C and D all twice daily. RESULTS: There was significant decrease in mean IOP (within the range of 3.0 ± 1.0 mmHg daily which finally stabilized at 7.00 ± 1.0 mmHg) in all groups treated with both hot and cold extracts of ginger. CONCLUSION: Ginger lowers IOP in rabbits’ eyes and may be a useful agent in reducing IOP in humans as it is cheap, commonly available, relatively free from adverse effects and beneficial to all the major tissues of the body. eywords: Intraocular pressure, Ginger, Zingiber officinale, Topical applicatio