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Magnetic reconnection can be used for studying the geoeffective processes in the coupled Sun--Solar wind -- Magnetosphere dynamics leading to geomagnetic disturbance. In this study, 1-hour resolution solar wind plasma parameters from OMNIweb were used to investigate the relationship between moderate southward interplanetary magnetic field, IMF-Bz (i.e., Bz > -10 nT) and geomagnetic storm time disturbance, Dst, during the ascending, maximum and descending phases of solar cycle 23. Occurrences of different classes of geomagnetic storms during moderate southward Bz are reported. The occurrence of weak and moderate geomagnetic storms is more predominant during maximum solar activity than intense and super intense storms. It was found that 10.11 % (181) of all the classes of the storm were intense, and 0.17 % (3) were super intense storms. Furthermore, it was found that 4 (2.2 %) out of the 181 intense storms were caused by southward Bz > -10 nT which were associated with the complex structure due to the high-speed solar wind stream and corotating interacting region. In such a complex structure and Bz > -10nT, we observed that an intense geomagnetic storm rarely occurs and if it does, would be predominant around solar maximum. It was found that longduration (Δt > 6 hrs) of southward Bz (i.e., -10 nT < Bz ≤ -3:6 nT) can also lead to an intense geomagnetic storm during the solar maximum and descending phase (moderate solar activity) of a solar cycle. The complex structure of intense geomagnetic storms associated with the Bz > -10nT is rare and possesses a special configuration of magnetic field and solar wind parameters structures which are CIR manifestations. [ABSTRACT FROM AUTHOR]

A short review of the pattern and morphology of the equatorial plasma drift velocities, particularly during the evening-time Pre-reversal enhancement (PRE) period in the African region had been presented. The seasonal PRE peak values across some locations in the West-African region were considered and compared with other sectors of the world. While most plasma drift observations in the African region were calculated from ionosonde measurements, the observations from other sectors involved direct measurement from satellite and the Incoherent Scatter Radar (ISR) observations. The importance of the PRE in ionospheric electrodynamics was highlighted, the better in the use of either the virtual or real heights of the F-layer in inferring vertical drift velocities were enumerated, revealing the strengths and weakness of each method. The general observations revealed that PRE peak magnitude is commonly weaker in the African region in comparison with the American/Peruvian and Indian sectors, seasonal and solar activity dependent, and could be higher during either magnetic quiet or disturbed activity than when both magnetic activity conditions are combined. The first work to present a regional PRE model around the African equatorial ionization anomaly region (Adebesin et al model) was mentioned. The relevance of the E × B drift in quantifying the daytime equatorial electrojet (EEJ) current was also discussed. [ABSTRACT FROM AUTHOR]

Background: Malignant glaucoma is an ocular emergency and may lead to blindness if not promptly recognized and treated effectively. It is usually reported after trabeculectomy, and spontaneous or bilateral cases are not common in the literature. Case report: This article reports the case of a Nigerian woman who developed spontaneous bilateral malignant glaucoma with resultant visual impairment. A literature review on the subject is also undertaken. Possible etiology and management challenges of the case are also discussed. Conclusion: This study is aimed at drawing attention to this potentially blinding eye disease, and ultimately improves knowledge on its diagnosis and management, to reduce the visual morbidity. [ABSTRACT FROM AUTHOR]

Background: The aim is to report cases of unusual and infrequent complication of otitis media in North-central Nigeria, as well as evaluate their outcome. We present 7 case reports of patients with unusual complications from otitis media in our setting. Case 1: A fifteen year old Yoruba girl presented at the Accident and emergency of our hospital with a 2 week history of left sided ear ache, 10 day history of left sided ear discharge and 3 day history of jaw and neck stiffness. There was a positive history of use of 'Turari' locally prepared perfume and application of an ear drop from a local chemist. Caregiver said patient was fully immunized. Examination revealed a young girl, conscious and alert, not pale, anicteric with stiff neck, positive and rigid joints on movement. Case 2: An 8 year old Yoruba girl presented first to the eye clinic with 2 days history of swelling of the right eye, associated pain, reduction in vision and eyelid swelling without eye discharge or itch. There was a of purulent ear discharge 8 days prior to eye symptoms. No history of trauma was obtained. Examination revealed proptosis with zygomatic abscess extending to the post-auricular. She had incision and drainage with systemic and topical antibiotics for ear dressing. Outcome was uneventful. Conclusion: The unusual complication of otitis media still occurs in our environment usually due to late presentation and contamination of wound. Prevention is still the best option. [ABSTRACT FROM AUTHOR]

The limitation of ionospheric models in describing short-term ionospheric events has led to the development of data assimilative models e.g. the International Reference Ionosphere extended to Plasmasphere (IRI-Plas) model . This paper compares the IRI-Plas derived total electron content (TEC), the peak height (hmF2) and critical frequency (foF2) of the F2-layer with those obtained from Global Positioning System (GPS) receiver's and Digisonde Precision Sounder (DPS-4) measurements over Ilorin (Geog. Lat. 8.50 o N; Long. 4.50 o E, dip: - 7.9 o ) during geomagnetic storm days. The model estimation was done by assimilation of Ionosonde foF2 and TEC derived from GPS (GPS-TEC) and Global Ionospheric Map (GIM-TEC) into the model code. In order to study the effect of data assimilation on the model's representation, the "no input" option of the model was used as reference. The result shows that with the exception of the foF2 assimilation mode, all the options generally reproduced TEC quite well for all the storm days considered. Overall, the model adjusted with GPS-TEC gives the best prediction of TEC as it reduced the prediction error of TEC by a multiple of up to three compared to using the GIM-TEC. Also, all the options failed to reproduce the storm induced prominent features in the storm-time features of foF2 and hmF2. In other word, assimilation with the TEC does not generally improve the storm-time predictions of foF2 and hmF2 at the station. Consequently, for storm-time estimation of the F2-layer peak parameters, the 'no input' representation of the model is more valid at this station.

Aims and Objectives: There is a paucity of data onthe human resourcesand ophthalmic equipmentavailable for the diagnosis and management of glaucoma in Nigeria. This study is aimed at describing the ophthalmic human resources, as well as available and functioning equipment used in diagnosing and managing glaucoma in Lagos State, Nigeria., Materials and Methods: This was a prospective multicentre cross sectional study.Data on human resources and equipmentavailable were collected from all government tertiaryand secondary health institutions in the state. One large-practice private eye hospital in the state was included for comparative purposes., Results: The average number of ophthalmologists per hospital was 1.3 and 4.5 in the secondary and tertiary centres respectively, with overall ophthalmologists to population ratio of 1:400,000, and ophthalmic nurses to population ratio of 1:150,000. There were only 2 full time low vision therapists and 3 equipment technicians. Only the private hospital had a dedicated patient counsellor and an eye unit manager. 64% of ophthalmic equipment in the government sector were functioning compared with 100% in the private centre. Overall, equipment to population ratios were; slit lamp=1:517,000, 78/90D lens=1:1,487,000, tonometer=1:660,000, visual field analyser=1:2,380,000, and pachymeter=1:5,950,000., Conclusions: Current population ratios for ophthalmologists and ophthalmic nurses in the state meets vision 2020 recommendations, but there are shortages of other key human resources such as equipment technicians, low vision therapists and patient counsellors. In addition, equipment required for the management of glaucoma wereinadequate, not available or not functioning. Findings from this study suggest that there is an urgent need for increased government funding to glaucoma services in Lagos State.

Corneal scarring is the fourth largest cause of blindness globally, and a much more prominent factor in developing countries. Blindness from corneal scarring is largely a preventable phenomenon, and is capable of causing significant morbidity that can last for a lifetime. A significant proportion of these cases are caused by the use of harmful traditional eye medicines/remedies, and are used and prescribed by friends, relatives and traditional healers, with widespread use especially in developing countries. Use of traditional remedies can also cause harm indirectly by causing delays before seeking medical treatment. Reducing corneal scarring from the use of harmful traditional medicine is through a combination of approaches with the key strategies being community diagnosis, education, participation, and intervention, with provision of basic eye care integrated into the primary health care of the community. Collaboration with traditional healers in the community is also another approach that has been found to be useful.

Objective: To determine the prevalence of visual impairment among commercial intercity vehicle drivers (CIVDs) in Ilorin, Nigeria., Design: A cross-sectional descriptive study., Participants: Among the estimated 450 drivers operating in 5 motor parks for CIVDs in Ilorin, 399 drivers participated in the study., Methods: A structured questionnaire was administered at the motor parks to consecutive and consenting drivers, and basic ocular examinations were done., Results: Using the Federal Road Safety Commission's requirement for commercial drivers in Nigeria, the prevalence of drivers with inadequate visual acuity (VA) was determined to be 11.5%, and 3.3% had monocular blindness. The prevalence of abnormal colour vision and visual field loss was 4.3% and 5.5%, respectively. There was no statistically significant relationship between visual impairment (VA and visual fields) and involvement in road traffic accidents (p > 0.05). Uncorrected refractive error, cataract, and glaucoma were the commonest causes of visual defects. Three hundred thirty-seven drivers (84.5%) did not have their eyes tested at first licensing and 370 drivers (92.7%) did not have testing at least once during renewals., Conclusions: A significant number of CIVDs in Ilorin are operating with VA that is far below the expected for their class of licence, and another unacceptably high percentage did not undergo any form of ocular examination prior to obtaining their driving licence. There is a need for renewed efforts to enforce a compulsory basic ocular examination for all prospective commercial drivers, and to ensure that the visual requirement for driving is met.

Introduction: HIV is assuming an alarming pandemic worldwide and presently in Nigeria it is a source of concern to all and sundry., Aim: To review the demography of cases positive for HIV in the eye clinic over a 5-year period and to identify ocular diseases that have high predictive value for HIV., Methods: A retrospective study of all the patients that were screened for HIV in the eye clinic over a 5-year period was done. Screening was by ELISA method with confirmation by Western blot test., Results: A total of 60 patients were screened and 26 (43.3%) of them were HIV positive. The male to female ratio of HIV positive patients was 1:1. All the seropositive patients were between the ages of 20-49 years and about a third were students from the higher institutions. Half of the patients were single. Diagnoses with high predictive values were Herpes Zoster Ophthalmicus (62%), Steven Johnson syndrome (50%), HIV retinopathy (75%), Bilateral Unresolving Toxoplasmosis (42%). The common presentations however are Herpes Zoster Ophthalmicus (HZO) and unresolving bilateral Uveitis., Conclusion: HIV and ocular involvement is increasing in Ilorin. The high-risk groups among patients presenting to the hospital are students of higher institutions and Soldiers. Diseases of high predictive indices are Herpes zoster Ophthalmicus, Steven Johnson's syndrome, HIV retinopathy.