Vessel density, macula thickness and foveal avascular zone measurements in young African adults with moderate myopia: A pilot study.

PURPOSE: The aim of this study was to investigate the association between macula thickness and vessel density in African myopic and emmetropic eyes through the use of Spectral Domain Optical Coherence Tomography (OCT). METHODS: The study population comprised African adults aged 18-35 years old. The study was conducted at a University eye clinic located in Durban, South Africa. Purposive sampling was utilised to obtain 59 participants of whom 24 were myopes and 35 were emmetropes. Vessel density (VD), foveal avascular zone (FAZ) and retinal thickness (RT) were obtained using the Heidelberg Spectralis OCT with angiography. Thereafter, a multivariate linear regression was used to investigate associations between the spherical equivalent myopic refractive error and VD, FAZ and RT for the myopic group only. RESULTS: Myopic participants had a mean spherical equivalent (MSE) and standard deviation (SD) of -4.79 D (1.27) while the emmetropic group had an MSE (SD) of -0.32 D (0.46). Both superficial and deep VD were significantly decreased at the central fovea (radius (r) = 0.4 mm), peri-foveal (r = 1.10-1.45 mm) and para-foveal (r = 0.75-1.10 mm) sectors in myopes when compared with emmetropes. Myopes showed a significant reduction in RT in the inner retinal layer across the inferior and temporal zones of the peri-foveal region as well as the inferior and temporal zones of the para-foveal region when compared with emmetropes. A significantly smaller FAZ was found at both the superficial and deep vascular plexuses (p < 0.001). In African myopes, significant associations were not found between MSE and VD or FAZ and macula retinal thickness. CONCLUSION: Retinal vascular and thickness reduction may occur in young African adults with moderate myopia. A broad-based study targeting VD and IRT in African myopes is proposed to confirm preclinical myopic macula disruptions in adults of African ethnicity. OCT angiography should be considered when monitoring progressive myopia.

The relationship between retinal structure and visual function in non-immuno-compromised people living with HIV without retinitis on antiretroviral therapy.

BACKGROUND: This study sought to establish the association between retinal morphology, visual function and linear parameters of cerebral atrophy in non-immunocompromised people living with HIV (NIPLHIV). METHODS: Sixty participants (30 NIPLHIV, 30 controls), aged 18-45 years, were sourced from an outpatient clinic in South Africa. NIPLHIV on antiretroviral therapy (ART) had elevated CD4 counts and low viral loads. Macula thickness and volume measurements were obtained using the Spectralis optical coherence tomographer. Contrast sensitivity (CS), colour vision and visual-evoked potentials (VEP) were also obtained. Linear parameters of cerebral atrophy (Sylvian fissure ratio, SFR) and bicaudate nucleus ratio (BCR) were all acquired from computed tomography (CT) scans. Associations between retinal thickness and volume and visual function were established by principal component factor analysis. RESULTS: CS scores were indirectly associated with the Inner Nuclear Layer (INL)-ETDRS thickness and volume subfields (co-efficient = -0.07; p = 0.02 and -0.11; p = 0.001), respectively. F100 total error scores (TES) were directly associated with the thicknesses of Ganglion Cell Layer-ETDRS subfields (co-efficient = 6.06; p = 0.04) but indirectly associated with INL-ETDRS subfields (co-efficient = -5.49; p = 0.04). F100-TES were indirectly associated with volumes of RNFL (Retinal Nerve Fibre Layer)-ETDRS subfields (co-efficient = -5.54; p = 0.02) and inner retina -ETDRS subfields (co-efficient = -6.70; p = 0.02). P100 latency was directly associated with RNFL-ETDRS subfield thickness (co-efficient = 2.90; p = 0.02) and volumes of outer retina subfields (co-efficient = 2.72; p = 0.04). CS scores were directly associated with SFR (co-efficient = -0.04; p = 0.01). F100-TES were directly associated with BCR (co-efficient = 0.003; p = 0.004) and SFR (co-efficient = 0.002; p = 0.02). P100 latency was indirectly associated with BCR (co-efficient = -0.001; p = 0.03). CONCLUSION: The recognition of associations may be the first step in the proposal to develop a framework for the surveillance of vision in patients with NIPLHIV. We recommend a study of the sample population to track the stability of these observations before general recommendations for clinical care.

The Integrity of Retinal Morphology in Non-immunocompromised People Living with HIV on Antiretroviral Therapy.

SIGNIFICANCE: Non-immunocompromised people living with HIV (NIPLHIV) share a similar immunocompetence to non-HIV (HIV) people with an elevated cluster of differentiation 4 (CD4) count in the era of antiretroviral therapy (ART). This has reduced the incidence of HIV retinopathy, thus raising the question of the integrity of the retinal morphology in NIPLHIV with longer life expectancy. PURPOSE: The study assessed the retinal thickness and volume of NIPLHIV without retinitis on ART and attempted to find associations with linear parameters of cerebral atrophy. METHODS: The study was conducted at a public hospital in South Africa. All people living with HIV were on ART with CD4 counts above 350 cells/mm3 and viral loads less than 10,000 copies/mL. The Heidelberg Spectralis ocular coherence tomographer assessed the retinal thickness and volume for comparison between 30 NIPLHIV and 30 HIV-negative participants. A subset of the HIV group obtained a computed tomography scan to determine the bicaudate ratio and the sylvian fissure ratio to assess cerebral atrophy. Independent t tests were performed to identify differences in retinal thickness and volume. Multivariate linear regressions measured associations between retinal thickness and volume with cerebral atrophy. RESULTS: The NIPLHIV group had a thicker mean global temporal subfields at Early Treatment Diabetic Retinopathy Study (ETDRS) 3 mm (P = .047) and ETDRS 6 mm (P = .03). The mean global temporal subfield volume at ETDRS 3 mm was also increased in the NIPLHIV group (P = .02). Nasal macula retinal nerve fiber layer thickness and the inferior inner nuclear layer macula volume were directly related to the bicaudate ratio, whereas the volumes at the outer retinal layer subfields of the macula were inversely related to sylvian fissure ratio in NIPLHIV. CONCLUSIONS: Macula thickness and volumetric differences do exist in NIPLHIV. Practitioners should keep NIPLHIV under retinal morphometric surveillance because they live longer. Associations of cerebral atrophy with retinal morphology may be used to monitor cerebral atrophy in NIPLIV on ART.

Utilisation pattern of ophthalmic services in Ashanti Region, Ghana.

BACKGROUND:  Best practice in optometry and ophthalmology recommends regular visits to eye care professionals, as routine eye examinations support early detection of ocular defects and associated systemic, sometimes potentially life-threatening, conditions. AIM:  The study sought to determine the utilisation of ophthalmic services and its associated factors in the Ashanti region of Ghana. SETTING:  Fifty electoral areas in 10 of the 43 districts in the Ashanti region of Ghana. METHODS:  A total of 1615 participants, aged 18 years and above, were randomly selected in the Ashanti region of Ghana for this population-based, cross-sectional survey. The factors associated with having had an eye examination were guided by Andersen's Behavioural Model. The data were analysed using multiple logistic regression, employing the IBM SPSS software, version 25. RESULTS:  After statistical adjustments, compared with the 18-29-year-old age group, older participants were found to be more likely to utilise eye care services: In addition, participants with higher formal education had higher odds for eye care utilisation compared with no former education: Being hypertensive, self-reported vision problems and feeling that regular eye examinations are important, were statistically associated with eye care utilisation. CONCLUSION:  There is alarmingly poor utilisation of ophthalmic services in the Ashanti region of Ghana. Effective programmes to promote public health by addressing the socio-economic and individual barriers hindering the uptake of ophthalmic services in the Ashanti region of Ghana are thus necessary.Contribution: The study addresses a gap in the knowledge of factors associated with ophthalmic services utilisation in the Ashanti region of Ghana.

Inflammatory mechanisms contributing to retinal alterations in HIV infection and long-term ART.

People living with HIV (PLWH) may face an increased risk of eye complications associated with ageing, chronic inflammation, and the toxicity arising from long-term antiretroviral therapy (ART). This review aims to understand how inflammatory pathways contribute to retinal alterations observed in PLWH on long-term ART. This review was conducted using four electronic database searches, namely Scopus, Hinari, Google Scholar, and PubMed; from 1996 (when ART became available) until January 2022, without language restriction. Sources from clinical trials, meta-analyses, randomised controlled trials, and systematic reviews were used. Dysregulated para-inflammation (chronic inflammation) damages the blood-retina barrier, resulting in the altered retinal immune privilege and leading to the development of retinal and blood vessel changes. There is an interplay between the effects of the disease versus ART. ART causes mitochondrial toxicity, which affects the retinal ganglion cells and retinal pigment epithelium (RPE) due to oxidative stress. Infection by HIV also affects retinal microglia, which contributes to RPE damage. Both of these mechanisms affect the blood vessels. Assessing the integrity of the inner and outer blood-retina barrier is a pivotal point in pinpointing the pathogenesis of inner retinal alterations. Optical coherence tomography is a valuable tool to assess these changes. There is a paucity of research to understand how these structural changes may affect visual function, such as contrast sensitivity and colour vision.

Ophthalmic services utilisation and associated factors in the Ashanti region, Ghana.

Objective: This survey determined the utilisation of eye care services and associated factors among adults in the Ashanti region of Ghana. Design: A population-based cross-sectional descriptive study. Method: Data for this study was collected from 1615 randomly selected individuals in the Ashanti region of Ghana, using a structured, pretested interviewer-guided questionnaire. Information regarding the accessibility and determinants of, and barriers to, eye care services was based on self-reports, using the WHO Eye Care Services Assessment Questionnaire. Inferential analyses were performed using the chi-square test for statistical significance, set at p=0.05. Setting: Ashanti Region, Ghana. Participants: One thousand six hundred and fifteen randomly selected adults. Results: Public eye care facilities were used by 58.2% of the participants for their last eye exam. Of the participants, 47.0% had travelled less than five kilometres for their last eye exam. Waiting time and service cost were participants' most frequently cited challenges in seeking care. No need felt (40.1%), self-medication (37.7%) and cost (22.2%) were the most frequently mentioned barriers to seeking ophthalmic services. Conclusion: The major challenges encountered in seeking eye care services were waiting time and cost of service. Major barriers to ophthalmic services utilisation were no need felt, self-medication and cost. Factors such as cost, lack of felt need and self-medication, which serve as barriers to utilising eye care services, should be addressed by stake-holders through eye health education and promotion. Funding: None declared.

The integrity of psychophysical visual function in non-immunocompromised PLHIV (NIPLHIV) without retinitis on antiretroviral therapy (ART).

Purpose: The present study investigated the integrity of contrast sensitivity (CS), colour vision, and pattern evoked vision potentials (VEP) in non-immunocompromised people living with HIV (NIPLHIV) without retinitis. Methods: All participants were visually asymptomatic and no history of ocular disorders, with CD4 counts above 350 cells/mm3, low viral loads and on ART. Thirty NIPLHIV and 30 age-matched HIV negative control groups underwent F100 hue colour assessment, Pelli-Robson contrast sensitivity assessment and pattern-reversal VEP. Results: The median F100 total error scores for NIPLHIV and controls was 33 (IQR: 28;41) and 28 (IQR: 26;48.50) respectively, this was statistically different (p= 0.020). The median P100 amplitude for NIPLHIV was 5.75 µV (IQR: 4.4;8.85) and 4.05 µV (IQR: 3.2;5.8) for controls, this was statistically different (p=0.045). The mean LogCS score 1.83±0.14 and the median P100 peak latency was 105.45 msec (IQR: 102.98;108.98) for NIPLHIV. Higher CD4+ counts were significantly associated with having higher F100 total error scores (OR=0.995; p=0.018), lower P100 amplitudes (OR=1.007; p=0.010) and higher P100 latencies (OR=0.994; p=0.011). Conclusion: Contrast sensitivity function, colour vision, and VEP were uncompromised in NIPLHIV. Associations between CD4 counts with F100 total error scores and P100 latency may aid in the surveillance of vision of NIPLHIV.

Evidence of the Amplitude of Accommodation of School-Going Children in the 21st Century.

Purpose: The study sought to compare the normative amplitude of accommodation (AoA) in school-going children from studies in the 21st century, based on pooled estimates from meta-analyses, to assess their agreement to Hofstetter's average formula. Methods: A PRISMA checklist was used to conduct the review. PubMed, EBSCOHOST and Medline electronic databases were employed, and hand searching resulting in 259 studies up to July 2021. After title and abstract screening, 12 studies underwent full-text screening, resulting in five studies for data extraction. The pooled effect size was determined using meta-analyses for sub-groups by age. A one-sample t-test was used to compare the pool-effect size estimates (monocular) to the expected AoA from Hofstetter's average formula. Results: The comparison of pool estimates of AoA with the expected Hofstetter's average formula for the age sub-groups showed significant mean differences for: six-year olds: mean difference of -3.4 D (95% CI: -5.85; -1.04; p = 0.025); nine-year olds: mean difference of -4.1D (95% CI: -7.95; -0.20; p = 0.043); ten-year olds: mean difference of -4.6D (95% CI: -8.57; -0.54; p = 0.035) and 11-year olds: mean difference of -5.2 D (95% CI: -8.06; -2.40; p = 0.005). According to the quality assessment tool used, overall, the body of evidence was of good quality. Conclusion: Hofstetter's prediction of normative amplitude of accommodation today may over-estimate for children aged six, nine, 10 and 11. The observed under-accommodation estimates from these comparisons may warrant consideration in assessing for a larger lag of accommodation in these age groups with myopia or pre-myopia, as part of the surveillance for progression.

The Effect of Home-Based Dichoptic Therapy on Young Adults with Non-Strabismic Anisometropic Amblyopia on Stereo Acuity.

Aim: To evaluate the effect of home-based dichoptic visual therapy using anaglyphic red-green filters on the stereo acuity in a sample of young adults with non-strabismic anisometropic amblyopia. Methods: The study was observational and cross-sectional in design. Two groups (experimental vs control) were sourced using purposive sampling of young adults with non-strabismic amblyopia (experimental group) in comparison to an age-match control group without amblyopia. For the purpose of refractive adaptation, all participants in both groups were asked to wear their spectacle correction constantly for at least 16 weeks prior to exposure to home-based dichoptic therapy. Stereo acuity measurements using the Stereo Fly test were obtained before and after 40 hours exposure to home-based dichoptic therapy. The changes in stereo acuity post eight weeks (40 hours) training from baseline measurements was obtained. The difference in medians between the experimental and control groups using the Mann-Whitney U-test was measured with significance set at P value of <0.05. Results: A total of 38 young adults (19 males, 19 females) with a mean age of 24.05 ± 5.66 years were enrolled in this study. Nineteen anisometropic amblyopes comprised the experimental group, fifteen of which were classified as moderate amblyopia (6/12-6/36) and 19 non-amblyopes comprised the control group. Home-based dichoptic therapy used on the experimental group after 8 weeks showed a significant improvement in stereo-acuity with a mean improvement of 345.26 ± 184.85 sec arc-1 [IQR:260;600; p<0.001] when compared to the control group. Conclusion: Home-based dichoptic therapy improved stereo-acuity in non-strabismic anisometropic amblyopes (moderate) in young adults. Thus suggesting that binocularity can improve in anisometropic adult amblyopes with a treatment modality that may be a convenient option better suit the demanding lifestyle of economically active adults who may not be able to comply with clinic-based therapy.

Screen-based behaviour in children is more than meets the eye.

Increased screen time (ST) in children is quickly becoming a public health concern as children are now reliant on technology for social interaction and educational development. The eye-health community has paid considerable attention to this in the recent literature, documenting it as digital eye strain. Continual close eye work and a lack of outdoor play contribute to digital eye strain and today's myopia epidemic. This is a cause for concern for public health stakeholders insofar as it leads to sedentary, screen-based behaviour (SSB) in children. This results in a lack of physical activity and impacts both their bodies and their mental health. The potentially harmful effects of prolonged screen exposure on developing brains and bodies are likely to be unique and significant as physiological growth changes intersect with exponentially expanding e-platforms. While embracing the benefits of a highly digitalised world, we need to simultaneously mitigate the potential risks they pose to the health of growing children.

A protocol for a scoping review to map the assessment approaches in optometry education programmes globally.

BACKGROUND: The training of optometrists aims to prepare practitioners with critical thinking skills who utilise their education and experience to solve clinical problems in real-life practice. Professional competencies should inform assessment, and as such, assessment methods for learning should encompass a wide range of approaches. The objective of this scoping review is therefore to map assessment approaches utilised within optometry education programmes globally. METHODS: This study is a scoping review based on the PRISMA methodology. The review will be guided by the following research question, "What are the assessment approaches that inform optometry training globally?". This was validated by the Population-Concept-Context framework according to the methodology for Joanna Briggs Institution Scoping Reviews. Relevant peer-reviewed studies and grey literature conducted during the last 10 years will be identified from electronic databases including CINAHL, PubMed, PROquest and ERIC. The search strings using keywords such as "Optometry students and staff", "Assessments" and "Optometry education" will be conducted using Boolean logic. An independent reviewer will conduct all title screening, two independent reviewers will conduct abstract and full article screening, followed by data extraction. Thereafter, a thematic analysis will be conducted. The Mixed Method Appraisal Tool version 2018 will be used for quality appraisal of mapped studies. DISCUSSION: The review will document evidence of assessment approaches utilised in optometry training globally. Considering the exit level competencies required in the basic job function of an optometrist, a coherence in assessment approaches and relevant rationale for these would be expected, if the accredited (regulated) training programmes follow a competency-based model.

A case study of digital eye strain in a university student population during the 2020 COVID-19 lockdown in South Africa: evidence of an emerging public health issue.

Background: The COVID-19 pandemic resulted in a nationwide lockdown in South Africa, initiating a shift in society's interaction to the online space. Students therefore became reliant on electronic devices for learning. Objective: The study aimed to investigate the prevalence of digital eye strain (DES) in a university student population during the nationwide COVID-19 lockdown in South Africa. Methods: Randomly sampled 290 university students were surveyed online about their screen time and DES during lockdown. The survey included a validated screen time questionnaire to measure screen time in hours per day and a validated computer vision syndrome questionnaire (CVS-Q) to measure the frequency and intensity of symptoms during edevice use (s). Descriptive statistics were used to analyze CVS-Q scores and screen time. Results: The mean (SD) age of the sample was 21.04 _ 2.32 years. Of these, 82.41% used smartphone devices and 55.52% of the participants did not use any optical correction. The prevalence of DES during COVID-19 lockdown in 2020 was 64.24%. Screen time on an average weekday and over the weekend, as a primary activity, had a median of 13 hours per day during lockdown. Conclusion: The high prevalence of digital eye strain may be a harbinger of a decrease in student performance. Creating awareness of proper visual hygiene amongst students is paramount in decreasing the high prevalence of DES.

A Study to Assess the Feasibility of Utilising Virtual Reality for the Treatment of Accommodative and Vergence Infacility.

BACKGROUND: To assess the feasibility, as well as viability, of utilising gaming using virtual reality (VR) to treat accommodative and vergence infacilities. METHODS: Forty-two emmetropic and asymptomatic participants between the ages of 18 and 30, with normal binocular visual function, were selected for the study in 2018. Participants with binocular accommodative infacilities and/or vergence infacilities comprised the study population. The binocular accommodative facilities (BAF) were assessed using amplitude-scaled facilities (probe lens = 30% amplitude of accommodation; test distance = 45% amplitude of accommodation). All those with less than 10 cycles per minute (cpm) were regarded as failing. Vergence facilities were assessed using 12 pd base out and 3 pd base in prisms. All those with less than 15 cpm were regarded as failing. The participants were separated into age-matched experimental and control groups. The experimental group played a fast-paced game using Samsung Gear VR (SM-R323), whilst the control group watched a television film projected onto a two-dimensional screen at a distance of one metre. Pre-test and post-test binocular amplitude-scaled facilities and vergence facilities were measured for both groups after exposure for 25 minutes. RESULTS: There was a significant, mean increase in binocular accommodative facilities of 4.67 ± 5.05 cpm (p = 0.008) for the experimental group (n = 12). There was a significant mean increase in vergence facilities of 3.72 ± 3.18 cpm (p < 0.001) for the experimental group (n = 32). A statistically significant mean difference of 4.07 cpm (95%CI: 0.97, 9.19; p = 0.03) between the respective control and experimental groups was found for binocular accommodative facilities and 2.45 cpm (95%CI: 0.68, 4.22; p = 0.008) for vergence facilities. CONCLUSION: Binocular accommodative facilities and vergence facilities increased after 25 minutes of VR gaming in asymptomatic emmetropic participants with accommodative infacilities and vergence infacilities. However, due to the small-scale, unmasked and unrandomised nature of the study more research is needed to confirm the results of this study.

The Investigation of the Effect of Hyperglycemic Changes on Psychophysical Measurements of Visual Function in Pseudophakic People Living with Diabetes Mellitus.

PURPOSE: The purpose of this study was to show the effect of increasing blood glucose level (BGL) on psychophysical visual function represents by visual acuity and contrast sensitivity in pseudophakic people living with diabetes (PDM). STUDY DESIGN: This was quasi-experimental, quantitative study using a pretest-posttest approach. METHODS: The study was conducted at Gamalakhe community health centre located in Gamalakhe township and included a sample of 50 pseudophakic people living without diabetes mellitus (PWDM) and 50 pseudophakic PDM. BGL as well as psychophysical measurements of visual function were measured preprandial and postprandial. Visual acuity (VA) was measured at distance (4 m) and near (40 cm) using logMAR VA charts, and contrast sensitivity (CS) was measured at 50 cm using a Mars chart. The data collected were captured and subsequently analyzed using SPSS version 25. RESULTS: Glycemic changes measured preprandial and postprandial observed a mean increase of 2.06±1.35 mmol/L (p=0.350) and 1.08±0.47 mmol/L (p=0.291) in pseudophakia PDM and pseudophakic PWDM, respectively. CS showed a mean increase of 0.01±0.10 (p=0.23) and 0.002±0.02 (p=0.19) log units in PDM and PWDM, respectively; however, the independent t-test showed this was insignificant between PDM and PWDM (p=0.27). A insignificant mean increase of 0.01±0.04 log units (p=0.25) and 0.001±0.01 (p=0.32) in distance VA of pseudophakic PDM and PWDM was found, respectively. A mean increase of 0.001±0.01 log units (p=0.32) and 0.01±0.03 (p=0.06) near logMAR VA of pseudophakic PDM and PWDM was found, respectively. CONCLUSION: Acute hyperglycemic changes do not result in overall significant changes in visual acuity and contrast sensitivity in pseudophakic PDM and PWDM for an increase in glycemia of 2 mmol/L. We recommend studies investigate if changes occur for glycemic increases exceeding 2 mmol/L.

The Effect of Ocular Perfusion Pressure on Retinal Thickness in Young People with Presumed Systemic Hypotension.

Low ocular perfusion pressure (OPP) may increase the risk of optic neuropathy. This study investigated the effects of OPP on the ganglion cell complex (GCC) and optic nerve head-retinal nerve fibre layer (ONH-RNFL) thickness in presumed systemic hypotensives (PSH). Fifteen participants with PSH and 14 controls underwent automated sphygmomanometry and Icare tonometry to calculate OPP: mean OPP (MOPP), systolic OPP (SOPP), and diastolic OPP (DOPP). ONH-RNFL and macula GCC thickness were evaluated using the Optovue iVue optical coherence tomographer. Statistical analysis comprised independent t-tests, the Mann-Whitney U test and binary logistic regression analysis. There was no significant difference when comparing ONH-RNFL and macula GCC thickness between both groups. Increased MOPP (OR = 0.51; 95% CI: 0.27-0.97; p = 0.039) and SOPP (OR = 0.79; 95% CI: 0.64-0.98; p = 0.035) were significantly associated with a decreased risk of reductions in GCC total thickness. Increased SOPP (OR = 0.11; 95% CI: 0.01-0.89; p = 0.027) was significantly associated with a decreased risk of reductions in the average ONH-RNFL thickness. The study found no significant retinal thickness changes in PSH's, in comparison to the controls. The study established that, by increasing MOPP and SOPP, there was a decreased risk of reductions in the total GCC thickness and average ONH-RNFL thickness. Higher SOPP may decrease the possibility of retinal thinning of the GCC and ONH-RNFL. However, higher MOPP may decrease the odds of thinning of the GCC before ONH-RNFL changes.

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 15y 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.

The effect of gaming on accommodative and vergence facilities after exposure to virtual reality head-mounted display.

BACKGROUND: To investigate the change between accommodative and vergence facilities before and after exposure to gaming in a virtual reality (VR) device amongst participants with normal binocular visual function. METHODS: 62 participants between the ages of 18-30 years with normal binocular visual function and inter-pupillary distances between 51 and 70 mm were selected for the study. Spectacle and contact lenses users were excluded. The experimental group (n = 42) was exposed to gaming using Samsung Gear VR(SM -R323) whilst the control group (n = 20) watched a television film projected on a two-dimensional screen at 1 m. Pre-test and post-test binocular amplitude-scaled facilities and vergence facilities were obtained for both groups after exposures of 25 min. RESULTS: Binocular accommodative facilities for the experimental group had a mean pre-test and post-test facility of 11.14 ± 3.67 cpm and 13.38 ± 3.63 cpm, respectively, after gaming using VR device. The vergence facilities for the experimental group had a mean pre-test and post-test facility of 11.41 ± 3.86 cpm and 15.28 ± 4.93 cpm, respectively, after gaming using a VR device. Binocular accommodative facilities for the control group had a mean pre-test and post-test facility of 11.70 ± 3.2 cpm and 11.95 ± 3.4 cpm, respectively. Vergence facilities for the control group had a mean pre-test and post-test facility of 11.55 ± 6.4 cpm and 11.70 ± 4.9 cpm, respectively. The mean change for binocular accommodative facilities was 2.24 ± 3.43 cpm and 0.25 ± 1.25 cpm for the experimental and control group, respectively. The mean change for vergence facilities was 3.81 ± 3.09 cpm and 0.15 ± 2.72 cpm for the experimental and control group, respectively. Binocular accommodative facilities and vergence facility showed a statistically significant mean increase greater than the control group after gaming using a VR device using an independent t-test (p < 0.05). CONCLUSION: The results showed that binocular accommodative facilities and vergence facilities increased after 25 min of VR gaming in emmetropic participants under 30 years of age with inter-pupillary distances between 51 mm and 70 mm.

A pre-test post-test assessment of non-invasive keratograph break up time and corneal epithelial thickness after vaping.

BACKGROUND: The effects of electronic cigarettes on the ocular surface has yet to be shown. The purpose of the study was to assess the impact of e-cigarette use on the anterior corneal surface integrity. METHODS: Forty three males and 21 females with an average of 21years were required to vape 0.05ml of e-liquid of 8mg nicotine concentration. Corneal epithelial thickness (CET) and Non Invasive Keratograph Tear Break up Time (NIKBUT) measurements were obtained prior to and post vaping. The Optovue iVue optical coherence topographer was used to measure central; superior; inferior; nasal and temporal CET and NIKBUT was assessed using the Oculus Keratograph 5M. RESULTS: There was a mean increase for central corneal epithelial thickness of 0.3448 microns. The superior CET increased by 0.2414 microns. The inferior CET increased by 0.2931microns. The nasal CET increased by 0.2069 microns. The temporal CET increased by 0.2759 microns. The mean change in NIKBUT post-vaping was an increase of 1.40 seconds. All observations occurred at p > 0.05. CONCLUSION: The acute effect of e-cigarette use does not impact corneal epithelial thickness and non-invasive keratography tear break up time after 10 puffs mild exposure but more research is needed to assess if this remains the case with more frequent, higher exposure.

Ophthalmic services utilisation and associated factors in the Ashanti region, Ghana

Objective: This survey determined the utilisation of eye care services and associated factors among adults in the Ashanti region of Ghana. Design: A population-based cross-sectional descriptive study Method: Data for this study was collected from 1615 randomly selected individuals in the Ashanti region of Ghana, using a structured, pretested interviewer-guided questionnaire. Information regarding the accessibility and determinants of, and barriers to, eye care services was based on self-reports, using the WHO Eye Care Services Assessment Questionnaire. Inferential analyses were performed using the chi-square test for statistical significance, set at p=0.05.Setting: Ashanti Region, Ghana Participants: One thousand six hundred and fifteen randomly selected adults Results: Public eye care facilities were used by 58.2% of the participants for their last eye exam. Of the participants, 47.0% had travelled less than five kilometres for their last eye exam. Waiting time and service cost were participants' most frequently cited challenges in seeking care. No need felt (40.1%), self-medication (37.7%) and cost (22.2%) were the most frequently mentioned barriers to seeking ophthalmic services. Conclusion: The major challenges encountered in seeking eye care services were waiting time and cost of service. Major barriers to ophthalmic services utilisation were no need felt, self-medication and cost. Factors such as cost, lack of felt need and self-medication, which serve as barriers to utilising eye care services, should be addressed by stakeholders through eye health education and promotion

A correlation analysis of cone characteristics and central keratometric readings for the different stages of keratoconus.

BACKGROUND: Knowledge of the cone characteristics for the different stages of keratoconus may potentially assist practitioners in diagnosing and managing keratoconic patients. AIM: This study aims to determine if any correlation exists between the central keratometric readings and the cone characteristics for the different stages of keratoconus. SETTING: A university eye clinic. MATERIALS AND METHODS: In this retrospective study, a saturated sample of 190 eyes from 106 cases of previously diagnosed keratoconic patient files was analyzed. The stage of keratoconus and cone characteristics, namely, cone location, cone decentration, topographical patterns, and morphology were analyzed using an Oculus 3M corneal topographer. RESULTS: Analysis revealed a correlation between cone decentration and stage of keratoconus (P = 0.007). The association was found to exist when central K-readings were between 45D and 52D and with an apical cone decentration of 3-4 mm. No correlations were obtained for the stage of keratoconus and the cone location; topography and morphology. CONCLUSION: It can be concluded that cone apices are not central in all stages. Practitioners should consider the peripheral cornea when diagnosing and managing keratoconic patients. No correlation between stage, morphology or topography was respectively revealed.