Visual problems: a review of prevalence studies on visual impairment in school-age children

Childhood visual impairment(VI) have a significant impact on the educational achievement, career choices and social life of affected individual, and in children, is mainly due to either preventable or treatable causes. Reliable data on the prevalence and causes of VI in children will guide the development of a systematic vision screening program for its early detection and successful treatment of possible causes. The purpose of this literature review is to summarize the available data on prevalence and causes of VI in school-age children from various regions globally. A discussion on the major findings highlighting the definition criteria, classifications and limitations for further studies is also presented.

A review of paediatric vision screening protocols and guidelines

Vision screening plays an important role in the early detection of children who have or probably are predisposed to have specific visual problems. The validity and reliability of the screening batteries in relation to the age group to be screened, and the person administering the test as well as the referral and follow-up criteria contribute to the overall outcome of the vision screening. Despite the long history of vision screening and significant improvement in the development of screening protocols, no agreement exists concerning the age at which children should be screened, the exact test batteries that should be in eluded and who should conduct the screening. This review highlights some important aspects of the history of paediatric vision screening and available evidence in support of their use to detect visual conditions in children. It also examines some of the barriers against the development of paediatric vision screening models especially in low and medium income countries.

Anti-inflammatory effect of Heliotropium indicum Linn on lipopolysaccharide-induced uveitis in New Zealand white rabbits

AIM: To investigate the anti-inflammatory effect of an aqueous whole plant extract of Heliotropium indicum(HIE) on endotoxin-induced uveitis in New Zealand white rabbits.·METHODS: Clinical signs of uveitis including flares,iris hyperemia and miosis, were sought for and scored in1.0 mg/kg lipopolysaccharide(LPS)-induced uveitic rabbits treated orally with HIE(30-300 mg/kg),prednisolone(30 mg/kg), or normal saline(10 m L/kg). The number of polymorphonuclear neutrophils infiltrating, the protein concentration, as well as levels of tumor necrosis factor-α(TNF-α), prostaglandin E2(PGE2), and monocyte chemmoattrant protein-1(MCP-1) in the aqueous humor after the various treatments were also determined. A histopathological study of the anterior uveal was performed.· RESULTS: The extract and prednisolone-treatment significantly reduced(P ≤0.001) both the clinical scores of inflammation(1.0-1.8 compared to 4.40 ±0.40 in the normal saline-treated rabbits) and inflammatory cells infiltration. The level of protein, and the concentrationsof TNF-α, PGE2 and MCP-1 in the aqueous humor were also significantly reduced(P ≤0.001). Histopathological studies showed normal uveal morphology in the HIE and prednisolone-treated rabbits while normal saline-treated rabbits showed marked infiltration of inflammatory cells.· CONCLUSION: The HIE exhibits anti-inflammatory effect on LPS-induced uveitis possibly by reducing the production of pro-inflammatory mediators.

Associations between near work, outdoor activity, parental myopia and myopia among school children in Aba, Nigeria

●AIM:To assess the influence of near work,time outdoor and parental myopia on the prevalence of myopia in school children in Aba,Nigeria.●METHODS:Primary and secondary school children aged between 8 and 15 y were randomly recruited from 12 schools in Aba.Information on family history,near work and outdoor activity was obtained using myopia risk factor questionnaire.Cycloplegic refraction was performed using autorefraction technique.Myopia was defined as spherical equivalent refraction(SER)≤-0.50 D in the poorer eye.Data were analysed for 1197(male:538 and female:659)children with full relevant data.●RESULTS:Risk of developing myopia was positively associated with parental myopia[odds ratio(OR):6.80;95%CI,2.76-16.74;P<0.01)for one myopic parent and(OR:9.47;95%CI,3.88-23.13;P<0.01)for two myopic parents,longer daily reading hour(OR:1.21;95%CI,1.03-1.42;P=0.02)and less time outdoors(OR:0.8;95%CI,0.74-0.87;P<0.01).●CONCLUSION:Parental history of myopia is the most important risk factor associated with myopia.In addition,children with both parents being myopic has increased odds of developing myopia than those with one myopic parent.It is recommended therefore,that children spend more time outdoors as this could reduce the prevalence and progression of myopia.

Anti-glaucoma potential of Heliotropium indicum Linn in experimentally-induced glaucoma

Background:Heliotropium indicum is used as a traditional remedy for hypertension in Ghana.The aim of the study was to evaluate the anti-glaucoma potential of an aqueous whole plant extract of H.indicum to manage experimentally-induced glaucoma.Methods:The percentage change in intraocular pressure(IOP),after inducing acute glaucoma(15 mLkg^(−1) of 5%dextrose,i.v.),in New Zealand White rabbits pretreated with Heliotropium indicum aqueous extract(HIE)(30–300 mgkg^(−1)),acetazolamide(5 mgkg^(−1)),and normal saline(10 mLkg^(−1))per os were measured.IOPs were also monitored in chronic glaucoma in rabbits(induced by 1%prednisolone acetate drops,12 hourly for 21 days)after treatments with the same doses of HIE,acetazolamide,and normal saline for 2 weeks.The anti-oxidant property of the extract was assessed by assaying for glutathione levels in the aqueous humour.Glutamate concentration in the vitreous humour was also determined using ELISA technique.Histopathological assessment of the ciliary bodies was made.Results:The extract significantly reduced intraocular pressure(p≤0.05–0.001)in acute and chronic glaucoma,preserved glutathione levels and glutamate concentration(p≤0.01–0.001).Histological assessment of the ciliary body showed a decrease in inflammatory infiltration in the extract and acetazolamide-treated group compared with the normal saline-treated group.Conclusion:The aqueous whole plant extract of Heliotropium indicum has ocular hypotensive,anti-oxidant and possible neuro-protective effects,which therefore underscore its plausible utility as an anti-glaucoma drug with further investigation.