[Global ophthalmology : Update]. / Globale Ophthalmologie : Aktueller Stand.

The aim of global ophthalmology is to maximize vision, ocular health and functional ability, thereby contributing to overall health and well-being, social inclusion and quality of life of every individual worldwide. Currently, an estimated 1.1 billion people live with visual impairment, 90% of which can be prevented or cured through largely cost-effective interventions. At the same time, 90% of people affected live in regions with insufficient eye health coverage. This challenge drove the World Health Organization (WHO) and a group of nongovernmental organizations to launch "VISION 2020: the Right to Sight", a global campaign which recently concluded after 20 years. The achievements, challenges and lessons learned were identified and incorporated into the current campaign "2030 IN SIGHT".

Simulating the Effects of Partial Neural Conduction Delays in the Visual Evoked Potential.

Purpose: The purpose of this study was to understand the double peaks or broadening of P100 observed in some cases of optic neuritis by inducing conduction delays in healthy eyes through stimulus luminance manipulation in analogy to the perceptual Pulfrich effect. Methods: Checkerboard pattern reversal visual evoked potentials (VEPs) with check sizes of 0.8 degrees, 0.4 degrees, and 0.2 degrees were recorded in healthy participants using two experiment variants. Variant (1) involved binocular stimulation with inter-ocular luminance difference achieved by a 1.8 neutral density (ND) filter, along with monocular control conditions. Variant (2) included monocular stimulation with hemifields having a luminance difference (half of monitor with ND filter), along with single-hemifield control conditions. In both variants, VEP curves under mixed stimulation were compared to synthesized VEPs computed from offline summation of curves from the relevant control conditions, followed by assessing P100 characteristics. Results: Despite considerable variability between participants, the binocular variant demonstrated marked differences between VEPs from mixed recordings and synthesized curves, whereas in the hemifield variant, agreement was strong. The anticipated double peak or broadened deflection pattern was observed to varying extents in participants, often contingent on check size, with nominal peak time frequently failing to indicate partial conduction delays. Conclusions: The present findings corroborate the hypothesis that nominal peak time does not always reflect conduction delays if only a subset of fiber bundles is affected. Peak shape might provide additional diagnostic evidence of a partial conduction delay. Translational Relevance: Enhancing the understanding of VEP waveform changes associated with partial conduction delays could offer diagnostic insights for optic neuritis.

Computed tomography estimation of the prevalence of neuro-ophthalmic injuries in head trauma patients seen in a tertiary health facility in Ghana.

INTRODUCTION: Prevalence of traumatic brain injury (TBI) is extremely high and potentially associated with severe incapacitating consequences. Literature reports that 90% of road traffic deaths and injuries including TBI occur in low and middle-income countries including Ghana. Computed Tomography (CT) scan is the imaging modality of choice for the initial assessment of the extent of head injury. Some Neuro-ophthalmic injuries (NOI) may sometimes be ambiguous and indistinct although a serious injury with potential damaging consequences. Data on the prevalence of NOI post trauma is non-existent in Ghana to inform policy. The onus therefore lies on the Radiologist who will review the head CT scan to be very meticulous not to miss any NOI if present. We therefore decided to diligently review a large cross-sectional retrospective post trauma head CT scans for occurrence of NOI. OBJECTIVE: To determine the incidence of NOI secondary to head trauma and the possible loss of vision thereof in a retrospective study using patients' head CT scan data from a tertiary hospital's CT centre in Cape Coast, Ghana. METHOD: All head CT scans secondary to trauma for the period January 2016 to December 2018, were retrieved and carefully analysed. A total number of 1043 of head CT scan images were analyzed by Consultant Radiologists. RESULTS: Results showed out of 1043 CT scans reviewed, 742 (71,1%) were males and 301 (28.9%) were females. A total of 609 (58.4%) out of the 1043 patients sustained NOIs of various anatomical types. More Males 398 (65.4%) sustained NOI than females 211 (34.6%). The incidence of NOI was more among the youth as majority 167 (27.4%) of the patients were within the 18-29 years followed by 30-39 years bracket of 148 (24.3%). Fourteen anatomical types of NOI were elicited and further analysis revealed, intra-ocular foreign body to be the highest 107 (17.6%) cases, orbital floor fractures injury was 92 (15.1%) cases, with globe rupture injury and intraocular hemorrhage recording 79 (13.0%) cases each. Optic nerve injury was the least revealing 7 (1.1%) cases. There was a relationship between the gender of patient and the propensity to sustain NOI as males were more disposed to NOI than females. Road traffic accident (RTA) was the main pervasive cause of TBI and this accounted for 71.9% of all cases, followed by fall from height 24%, and the least cause of TBI was ascribed to gunshot injury of 0.33%. CONCLUSION: Prevalence of NOI is high. Urgent measures must therefore be implemented to reduce the RTA menace in general and to mitigate the associated NOI and possible loss of vision thereof.

Profile, knowledge, and attitude of contact lens users regarding contact lens wear in Ghana.

BACKGROUND: Contact lenses are gaining popularity in developing countries as an alternative to spectacles for the correction of refractive errors. It is needful, therefore, to generate information to guide the mode of practice, and assist the industry in developing products for the increasing contact-lenses-user population. The purpose of this study was to identify the demographic profile, as well as the knowledge, attitude to wear and care regimen of wearers of contact lenses in Ghana. METHODS: In a cross-sectional study, case folders of 87 users of contact lenses were selected from the database eye contact lenses practices. The folders were reviewed for the demographic profile, type, and purpose for which the contact lenses were prescribed. Forty-two (42) contact lenses users were then randomly surveyed, using a semi-structured questionnaire to collect information on their knowledge, lens wear regimen, and attitudes regarding lens hygiene. Chi-square test was used to test associations between demographics and lens wear variables. RESULTS: Out of the 87 cases reviewed, 46 (52.9%) were females and 41 (47.1%) males. Their ages ranged from 15 to 68 years with a mean age of 28.62 ± 9.38 years. The majority- 65 (75%) - were youthful (≤ 40 years), with the highest proportion of them - 46 (53%) - being between 20-29 years. The majority - 60 (68.9%) - had a tertiary level of education. Soft contact lenses were commonly worn by 68 (78.2%) users while 19 (21.8%) wore rigid gas permeable lenses. The purpose for wearing contact lenses included for vision correction - 46 (52.9%), followed by for cosmesis - 23 (26.4%) - and therapeutic reasons -18 (20.7%). The commonest refractive error corrected was myopia - 38 (43.7%), followed by astigmatism -19 (21.8%) and hyperopia 6 (6.9%). Among the 42 users who responded to the questionnaire, by proportion, the majority -17 users (40.5%) - were introduced to contact lenses by optometrists. All respondents reported previous symptoms associated with the use of their contact lenses, but slightly more than half, 25 (57.1%) did yearly follow-up visits. CONCLUSION: The majority of contact lenses used in Ghana are soft lenses, for the purpose of vision correction. The use of contact lenses was common among individuals in their early adulthood and those with tertiary education.

Meibomian Gland Dysfunction in a Youthful Clinical Sample in Ghana.

SIGNIFICANCE: This study showed a high frequency of nonobvious obstructive meibomian gland dysfunction, which can be detected only via the expression of the meibomian glands. The study advocates that meibomian gland expressibility should be a routine part of the clinical examination of patients especially those with dry eyes to avoid missing meibomian gland dysfunction among a youthful population. PURPOSE: The aim of this study was to estimate the frequency of meibomian gland dysfunction including asymptomatic and symptomatic meibomian gland dysfunction and obvious and nonobvious obstructive meibomian gland dysfunction among a youthful population in Ghana. METHODS: This was a clinic-based prospective cross-sectional study of consecutive patients visiting the University of Cape Coast Optometric clinic for comprehensive eye examination. RESULTS: Two hundred fifteen clinical subjects consented to participate in the study. Mean age of the entire sample was 21.9 (±3.8) years with an age range of 17 to 40 years. One hundred five males and 107 females participated. Frequency of meibomian gland dysfunction among the sample was 25.5% (95% confidence interval [CI], 19.8 to 31.6%). Frequencies of asymptomatic and symptomatic meibomian gland dysfunction were 10.1% and 15.4%, respectively. Frequencies of obvious and nonobvious obstructive meibomian gland dysfunction were 0.9% and 24.6%, respectively. In univariate logistic regression analysis, age (odds ratio, 1.246; 95% CI, 1.037 to 1.496; P = .019) was significantly associated, but sex (odds ratio, 1.315; 95% CI, 0.707 to 2.446; P = .387) was not significantly associated, with meibomian gland dysfunction. There was a statistically significant difference in the mean corneal staining scores between meibomian gland dysfunction subjects and non-meibomian gland dysfunction subjects (t = 3.51, P = .01). There was also a statistically significant difference in the mean tear breakup time between meibomian gland dysfunction subjects and non-meibomian gland dysfunction subjects (t = 4.44, P < .001). CONCLUSIONS: Because of the high frequency of nonobvious obstructive meibomian gland dysfunction, reliance on overt posterior lid margin abnormalities for the diagnosis of meibomian gland dysfunction may lead to underdiagnosis of meibomian gland dysfunction among clinicians in a youthful population.