The Ahmed Glaucoma Valve in Refractory Glaucoma: Experiences in Southwest Ethiopia

Background

The management of refractory glaucoma is a challenging task for any glaucoma surgeon. This study is aimed to evaluate the efficacy of Ahmed Glaucoma Valve implantation in refractory glaucomas in South-West Ethiopia.

Methods

A retrospective review was conducted on the charts of consecutive patients treated with Ahmed glaucoma valve implantation at Jimma University Specialized Hospital between August 2012 and August 2014. Success was defined as Intraocular Pressure (IOP) less than 22 mm Hg and greater than 5mm Hg at 6 months, with at least 30% reduction from baseline, without medical therapy (complete success) or either with or without medication (qualified successes).

Results

A total of 12 eyes of 11 patients were included. The mean age of patients was 40.7 (SD= 19.0) years; 63.6% of them were males. The main types of glaucoma were pseudoexfoliative (3 eyes), uveitic (2 eyes), chronic angle closure (2 eyes) and Juvenile Open Angle (JOAG) (2 eyes). The mean IOP was reduced from preoperative level (32.75±7.14 mmHg) to (15.75 ±4.35 mmHg) at six postoperative months, (P<0.001); 66.7% eyes had complete successes while 83.3% had qualified success. Intra-operative complications were encountered in 2(16.7%) eyes, while 5/12 (41.7%) eyes had post-operative complications-hypotony (one with choroidal effusion) and progression of cataract in 2 eyes each. Hypertensive phase was diagnosed in 2(16.7%) eyes.

Conclusion

The Ahmed glaucoma valve implant appears to be effective and relatively safe for treating complicated glaucomas with success rate comparable with those reported from other studies. KEYWORDS: Ahmed glaucoma valve, refractory glaucoma, complications, Ethiopia     

Risk factors for active trachoma and Chlamydia trachomatis infection in rural Ethiopia after mass treatment with azithromycin

Objectives To investigate risk factors for ocular Chlamydia trachomatis infection and active trachoma, comparing communities receiving or not receiving an intervention programme of community‐wide azithromycin treatment and health education. Methods In a 3‐year post‐intervention follow‐up survey, 1722 children aged 3–9 years, from randomly selected households in 37 communities, were examined for signs of active trachoma and had samples taken to test for ocular C. trachomatis by polymerase chain reaction. Multivariate random effects logistic regression analyses considered interventions at community level, adjusting for other independent risk factors as appropriate. Results Younger age, ocular discharge and flies on eyes were risk factors for active trachoma in communities with and without antibiotic treatment. After azithromycin treatment, odds of active trachoma were lower in children aged 6–9 years than in children aged 3–5 years (OR 0.48, 95% CI: 0.36–0.66) and higher for children with ocular discharge (OR 4.5, 95% CI: 2.6–7.7) or flies on their eyes (OR 2.5, 95% CI: 1.6–3.7). Odds of C. trachomatis infection were lower in children aged 6–9 years than in younger children (OR 0.47, 95% CI: 0.23–0.96); and in children who received 2 or 3 doses rather than 1 (OR 0.26, 95% CI: 0.08–0.88). Conclusions In communities that received or did not receive the mass antibiotic treatment, the same risk factors for C. trachomatis and active trachoma were identified. Education and environmental improvements need to supplement antibiotic campaigns in order to positively impact on these remaining child level risk factors.     

Stereoselective disposition of talinolol in man

The disposition of the beta-blocking drug talinolol is controlled by P-glycoprotein in man. Because talinolol is marketed as a racemate, we reevaluated the serum-concentration time profiles of talinolol of a previously published study with single intravenous (30 mg) and repeated oral talinolol (100 mg for 14 days) before and after comedication of rifampicin (600 mg per day for 9 days) in eight male healthy volunteers (age 22-26 years, body weight 67-84 kg) with respect to differences in the kinetic profiles of the two enantiomers S(-) talinolol and R(+) talinolol. Additionally, the metabolism of talinolol in human liver microsomes was examined. After oral administration, S(-) talinolol was slightly less absorbed and faster eliminated than R(+) talinolol. The absolute bioavailabilty of the R(+) enantiomer of talinolol was slightly but significantly higher than of its S(-) enantiomer. Coadministration of rifampicin further intensified this difference in the disposition of R(+) and S(-) talinolol (p < 0.05). Formation of 4-trans hydroxytalinolol was the major metabolic pathway in human liver microsomes. All Cl(int) values of S(-) were higher than of R(+) talinolol; 0.1 microM ketoconazole inhibited the formation of all metabolites. In conclusion, the stereoselectivity of talinolol disposition is of minor importance, and most likely caused by presystemic biotransformation via CYP3A4. The less active R(+) talinolol might be suitable for phenotyping P-glycoprotein expression in man.     

Ocular Biometry and Intra Ocular Lens Power among Cataract Patients in Rural Eastern Ethiopia

BackgroundThe objective of the study was to report on the main parameters of ocular biometry and Intraocular lens (IOL)power of patients attending a cataract surgical campaign in Eastern Ethiopia.MethodsThe study was a cross-sectional study on 765 eyes which were eligible for cataract surgery during a mass cataract surgical campaign conducted from April 04 to April 10, 2018 at Bisidimo Hospital, Eastern Ethiopia. Ocular biometric parameters were measured by automated keratorefractometer and Sonomed A-Scan (Model 300AP) using contact applanation method. Multiple linear regression analysis was done to determine association of ocular biometry components with socio demography of the study subjects.ResultsThe mean corneal curvature and anterior chamber depth (ACD, measured from corneal epithelium to lens) were found to be 7.61 mm and 2.88mm respectively. The mean axial length was estimated to be 22.98 mm. The mean refractive power of IOL was calculated to be 19.34D. The mean axial length in females was shorter than that of males by 0.24 (P - value = 0.01). The mean ACD in males was also larger than that of females by 0.1 (P - value = 0.001).ConclusionThis study provided a larger population based normative data on ocular biometry in Ethiopia. The female sex was a strong predictor of small axial length. Increasing age had no effect on axial length but was found to be a stronger predictor of shallow ACD.     

Boron and pyridinic nitrogen-doped graphene as potential catalysts for rechargeable non-aqueous sodium–air batteries

In this work, we performed density functional theory (DFT) analysis of nitrogen (N)- and boron (B)-doped graphene, and N,B-co-doped graphene as potential catalysts for rechargeable non-aqueous sodium–air batteries. Four steps of an NaO₂ growth and depletion mechanism model were implemented to study the effects of B- and N-doped and co-doped graphene on the reaction pathways, overpotentials, and equilibrium potentials. The DFT results revealed that two-boron- and three-nitrogen (pyridinic)-doped graphene exhibited plausible reaction pathways at the lowest overpotentials, especially during the charging process (approximately 200 mV), thus, significantly improving the oxygen reduction and oxidation reactions of pristine graphene. In addition, pyridinic nitrogen-doped graphene meaningfully increased the equilibrium potential by approximately 0.30 eV compared to the other graphene-based materials considered in this study. This detailed DFT study provides valuable data that can be used for the successful development of low-cost and efficient graphene-based catalysts for sodium–air battery systems operating with non-aqueous electrolyte.

We performed density functional theory analysis of heteroatom doped graphene as potential catalysts for rechargeable non-aqueous sodium–air batteries. Pyridinic nitrogen and boron doped graphene exhibited too low overpotential reaction pathways.     

Prevalence and risk factors analysis of bovine tuberculosis in cattle raised in mixed crop‐livestock farming system in Tigray region,Ethiopia

Bovine tuberculosis (BTB) is a disease of animal and public health importance in developing countries. In rural Ethiopia, there is potential for a shift in the epidemiologic of this disease driven by transformation of dairy industry. This includes gradual change from the traditional mixed crop‐livestock husbandry practice to a semi‐intensification system. It is therefore, essential to document the prevalence and risk factors of BTB to continuously update the designing and implementation of control and prevention strategies. Here, we present findings of a cross‐sectional study on the prevalence and associated risk factors of BTB among cattle reared under mixed crop‐livestock farming system in Tigray region, Ethiopia. A multistage purposive sampling approach was used to select districts, villages, herds and individual cattle. A total of 1,357 cattle from 310 herds were examined for BTB infection using a comparative intradermal tuberculin skin test (CIDT). Questionnaires were used to gather data on herd structure and herd management practices. A multilevel logistic mixed effect model was used to determine risk factors after accounting for clustering effect at three levels (village, herd and individual animal). Overall prevalence of BTB was 4.3% (95% CI = 3.4–5.6), with the highest prevalence recorded in Alamata district (5.6%) and lowest in Korem (1.6%). Multilevel logistic mixed effect model analysis identified exotic breed (OR = 3, p = 0.014), closed barn (OR = 2.6, p = 0.018), large herd size (OR = 2.6, p = 0.05) and purchase of cattle (OR = 2.1, p = 0.027) as important risk factors for BTB. Taken together, these findings suggest that the current dairy development program centred on the introduction of exotic and or crossed animals could have contributed to changing epidemiological situations of BTB in the study area.     

Implementation of tuberculosis preventive treatment among people living with HIV,South Sudan

ObjectiveTo describe an intervention to scale up tuberculosis preventive treatment for people living with human immunodeficiency virus (HIV) in South Sudan, 2017–2020.MethodsStaff of the health ministry and United States President’s Emergency Plan for AIDS Relief designed an intervention targeting the estimated 30 400 people living with HIV on antiretroviral therapy across South Sudan. The intervention comprised: (i) developing sensitization and operational guidance for clinicians to put tuberculosis preventive treatment delivery into clinical practice; (ii) disseminating monitoring and evaluation tools to document scale-up; (iii) implementing a programmatic pilot of tuberculosis preventive treatment; and (iv) identifying a mechanism for procurement and delivery of isoniazid to facilities dispensing tuberculosis preventive treatment. Staff aggregated routine programme data from facility registers on the numbers of people living with HIV who started on tuberculosis preventive treatment across all clinical sites providing this treatment during July 2019–March 2020.FindingsTuberculosis preventive treatment was implemented in 13 HIV treatment sites during July–October 2019, then in 26 sites during November 2019–March 2020. During July 2019–March 2020, 6503 people living with HIV started tuberculosis preventive treatment.ConclusionLessons for other low-resource settings may include supplementing national guidelines with health ministry directives, clinician guidance and training, and an implementation pilot. A cadre of field supervisors can rapidly disseminate a standardized approach to implementation and monitoring of tuberculosis preventive treatment, and this approach can be used to strengthen other tuberculosis–HIV services. Procuring a reliable and steady supply of tuberculosis preventive treatment medication is crucial.