Optometry

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Assessment of visual function amongst motor vehicle drivers in Maseru, Lesotho.
(2021) Moledi, Zubeta.; Van Staden, Diane Beverly.
Background: Driving is a primary mode of travel in many countries. It relies primarily on the function of vision to navigate roads and traffic safely. Ensuring good vision for motor vehicle drivers is therefore important to promote safety for all road users. Lesotho is a developing country, with road transportation central to the movement of people and goods within, and across the borders of the country. The absence of clear minimal requirements for visual function among holders of motor vehicle licences in Lesotho motivated this study. Aim: To assess the visual function of motor vehicle drivers in Maseru, Lesotho. Methods: A descriptive, mixed methods cross-sectional study employing systematic random sampling was conducted at the Traffic Department in Maseru, Lesotho. Active licensed drivers, both males and females, from 22–76 years of age participated in the study. Data was collected by means of key informant interviews, structured questionnaires and a comprehensive vision examination of all participants. Quantitative data was analysed using Strata version 14 software, while qualitative data was analysed descriptively. Results: The study included 460 licensed drivers with an overall mean age of 42.9 years, of which 64% (n=294) were men. One in five participants had not had an eye examination before obtaining their driving licence. Most participants (70.87%) had normal vision (6/9 or better) in the better-seeing eye, while 29.13% had visual acuity worse than 6/9 in the better-seeing eye. Among those with sub-normal vision, 29% had visual acuity ranging between 6/18 and 6/48 in the better-seeing eye. More than one third (39%) of participants had some form of refractive error, with myopia showing the highest distribution (46.46%), followed by astigmatism (32.96%) and hyperopia (24.59%). Of those with hyperopia, the majority (98%) were classified as having mild hyperopia (+0.50DS up to +2.00DS). Although myopia had the highest distribution, most cases were mild to moderate myopia (-0.50DS up to -5.75DS). The majority of participants (97.61%) passed the colour vision test, 53.70% achieved contrast sensitivity of up to 6/12 in the better eye and 99.6% achieved a measurement of 100 degrees for visual field test screening. Most participants did not wear spectacles when driving, with 37% of these having previously been advised to wear them based on identified need. Almost half (44%) of the participants reported to have been involved in road traffic accidents. Discussion: While most participants in this study presented with good vision for driving, it is concerning, that almost one in three (29%) had mild to moderate visual impairment and 39% had refractive error, yet they continued to drive without any form of refractive correction. Also, almost half of the participants (44%) had been involved in road traffic accidents, with almost one in five (19%) who had refractive error. It is possible that refractive error and visual impairment could have contributed to their involvement in road traffic accidents. The visual function findings in this study suggest that the Traffic Department in Lesotho should have guidelines on the minimum visual requirements for driving, as well as routine screening procedures. Conclusion: A significant proportion of the motor vehicle drivers in Lesotho have some form of compromised visual function, with many not undergoing an eye examination before obtaining a driver’s licence. If drivers are advised to have their eyes examined regularly, many visual function anomalies could be detected early and their vision corrected accordingly. The absence of effective screening methods for drivers in Lesotho could possibly be a contributor to the incidence of road traffic accidents in the country with the resultant negative socio-economic impacts.
The availability and accessibility of low vision services in Ashanti and Brong Ahafo Regions of Ghana.
(2018) Kyeremeh, Sylvester.; Mashige, Khathutshelo Percy.
Background: The prevalence of low vision on the African continent is generally high and varies across and within countries, as well as in people of different socioeconomic status. While regional studies on the prevalence of blindness and low vision in Ghana have been conducted, there is a lack of information on the availability and accessibility of low vision services in these regions. The aim of the study was to assess the availability and accessibility of low vision services in the Ashanti and Brong Ahafo regions of Ghana. Methods: This was a descriptive, quantitative, cross-sectional study design. Hand-delivered semi-structured questionnaires were used to collect information from eye care professionals selected from 58 eye care facilities within the Ashanti and Brong Ahafo regions of Ghana. In addition, face-to-face interviews were conducted with 29 low vision patients from the same regions. Results: Forty-four eye care facilities from the Ashanti region and 10 from the Brong Ahafo region responded to the questionnaire, giving an overall response rate of 93%. A total of 29 patients including 16 males and 13 females with a mean age of 33.79±17.42 years were interviewed from four different eye care facilities. Out of 50 eye care facilities who reported that they had low vision patients attending their clinics, 33 (66%) did not provide low vision services and 17 (34%) offered some form of this service. Eleven out of 15 (73.3%) patients reported that it was either difficult or very difficult to acquire optical low vision devices while 10 (83.3%) out of 12 patients reported the same about non-optical low vision devices. Of the 15 patients who responded to the questions on where they obtained their optical devices, 7 (47%) reported that they were donated to them, 2 (13%) obtained them from the market while 6 (40%) reported getting their devices from the hospitals or eye care facilities. For non-optical devices, the patients reported obtaining them from the market 5 (31%) and through donations 5 (31%). Others obtained them from the society for the blind 2 (15%), hospitals or eye clinics 2 (15%) and a resource centre 1 (8%). Barriers to the provision and uptake of low vision services included the lack of testing equipment, lack of assistive devices and high cost of services. Conclusions: Availability and accessibility of low vision services are limited in the Ashanti and Brong Ahafo regions. These findings should help to inform interventions to make low vision services available and accessible as well as to overcome the barriers to providing and utilising these services to minimise the impact of visual impairment.
Barriers to eye health care among school going children in Swaziland: towards the development of a framework for access to child eye health care.
(2018) Sukati, Velibanti Nhlanhla.; Moodley, Vanessa Raquel.; Mashige, Khathutshelo Percy.
Background: Good vision and eye health plays an important role in the overall development and well-being of a child. Visual impairment in children has a significant impact on their social interaction, quality of life, and economic independence. Providing accessible and equitable eye health delivery for all children, particularly the disadvantaged, requires establishing a balance between their eye care demands and the services a country can afford to supply. Purpose: The study aimed to investigate the barriers to child eye health services in the public health system in Swaziland in order to recommend, through the development of an access framework, strategies to improve access and address their specific eye health needs. Methods: A mixed methods study design was used in the study which entailed a document review of neighbouring country’s eye health policies, quantitative surveys to establish parents, teachers and eye health professionals knowledge and practices about children eye health; clinical facility assessment questionnaire to determine the availability of eye care facilities and services for children and qualitative interviews with Health and Education officials to determine current levels and factors that impact on access for children. The analyses included descriptive analysis for the quantitative data, thematic analysis for qualitative data and content analysis for the documents. The qualitative (interviews) and quantitative data (questionnaires) were triangulated to develop the draft access framework, and the Delphi technique used for experts’ input and comments for the draft access framework. Results: South Africa has national eye health guidelines that advocate for better public eye health services guided by formulated objectives with set targets. Although strides towards providing eye health care in Mozambique are noticeable, the country still lacks concrete eye health guidelines. Three major themes emerged from both the Health and Education interviews, these being; level of access, structural barriers and knowledge barriers to child eye care services. The absence of an eye care referral system, an outdated National Health Policy, the lack of or skewed distribution of human eye care resource and clinics, and inadequate knowledge about eye health care for children were the most important issues contributing to poor access and provision of ophthalmic services. Poor access to basic education excludes many children, particularly those from rural areas, from benefiting from school health programmes, despite these being characterized by poor service delivery. The clinical facility assessments indicated that only a few children presented to the public sector eye care facilities that are available in the country and that the majority lacked working equipment and essential drugs for patient management. In addition, low vision and contacts lens fitting services were lacking while only two out of the five clinics conducted outreach programmes at schools. Many (60.1%) parents reported that they have never taken their children for an eye test and 31.7% felt that their children’s vision was fine. The presence of a health facility in a community influenced early child eye examination (p=0.001). The majority (90.1%) of teachers indicated that they were able to detect signs and symptoms of eye diseases, although, this was insignificantly associated with those who indicated being well informed about eye health (p=0.089). Children wearing spectacles was significantly associated with teachers who indicated being well informed about eye health (p<0.001) and those who were more likely to advise parents to take their children for eye testing (p=0.003). Nine (60%) eye health practitioners felt that they were less informed about eye health problems among children and six (40%) reported being well informed. Eight (53.3%) respondents indicated that there were no school and community eye care outreach programmes and seven (46.7%) reported that their clinics offered outreach programmes. This is the first access framework study for child eye care in Swaziland and provides an opportunity to be a benchmark for other developing countries facing similar challenges. The framework advocates for a holistic approach in order to eliminate the isolation of eye health services. It further adopts a consumer oriented approach, with a particular focus on the current and future eye health status of children. The framework will serve as a foundation for eye health policy formulation and programmes aimed at redressing, promoting and preventing visual impairment or blindness. Conclusion: A carefully planned public health system, supported by an effective eye health plan and public health agencies, is needed to promote access to eye health services by children in the public education system in Swaziland. There is also a need for parents to be informed about basic child eye health in order to seek appropriate care. Teachers need adequate training and understanding about child eye health, including visual disabilities, to remove barriers in the teaching system. Developing and implementing guidelines for promoting access to child eye health may be useful to improve eye health service delivery in the country. The Swaziland government need to adopt and translate the framework into practice according to its intent as the information contained will be useful to the Ministry of Health and Social Welfare, Ministry of Education and Training, eye health professionals and parents.
A clinical description of anterior segment variables measured using optical coherence tomography in a healthy South African young adult population: the development of normal reference intervals.
(2018) Rampersad, Nishanee.; Hansraj Singh, Rekha.
Background: Assessment of anterior segment variables is important to screen, diagnose and monitor ocular anomalies. Previous studies, which have focused exclusively on Caucasian and Asian sub-populations with limited attention to South African sub-populations, suggest that anterior segment variable (corneal and anterior chamber angle) measurements vary with demographic and/or ocular factors. This study investigated anterior segment variables, measured using optical coherence tomography, in a healthy South African young adult population and develop a clinical biometric guideline with normal reference intervals. Methods: A quantitative cross-sectional research design was used. Multistage random sampling was used to select 700 participants from a university population. Anterior segment variables were measured using the Fourier-domain iVue100 Optical Coherence Tomographer. The Oculus Keratograph, Goldmann applanation tonometer and Nidek US-500 ultrasonographer were used to measure corneal topography, intraocular pressure (IOP) and axial biometry respectively. Data were analysed by descriptive and inferential statistics. The reference intervals were computed using the non-parametric method recommended by the Clinical and Laboratory Standards Institute. Results: The mean age of the sample, which consisted of 350 males and 350 females, was 20.4 ± 1.8 years. The anterior segment variable measurements of the right and left eyes showed high levels of interocular symmetry with intraclass correlation coefficients greater than 0.933 and marginal mean interocular differences. Accordingly, data from only the right eyes were analysed because of the high levels of interocular symmetry. The mean central corneal thickness (CCT) was 501.91 ± 33.74 μm and significantly thinner than the mean corneal thickness in each quadrant of the paracentral and peripheral cornea (p < 0.001). The mean minimum corneal thickness was 495.73 ± 33.89 μm and 1.23% thinner than the mean CCT measurement (p < 0.001). The thinnest point on the cornea was central for 94% of participants (n = 659). The anterior chamber angle (ACA) width variables, which included the angle-opening distance taken at 500 μm (AOD500) and trabecular-iris angle (TIA), were ~553 μm and ~37° respectively. The majority of participants showed ACA width variable measurements associated with open non-occludable ACAs. The temporal ACA had slightly higher variable measurements than the nasal ACA. The corneal thickness measurements in the different zones were normally distributed (p ≥ 0.095) whereas the ACA width variable measurements were asymmetrically distributed (p < 0.001). Black participants had significantly thinner mean corneal thickness measurements than Indian participants (range between 29.10 μm between 36.38 μm) for all zones (p < 0.001). For both the nasal and temporal ACAs, Black participants had 10 μm to 22 μm lower median AOD500 measurements (p ≥ 0.031) and slightly higher (less than 1°) median TIA measurements (p ≥ 0.068). The mean corneal thickness in males were 0.35 μm to 3.93 μm thicker compared with females (p ≥ 0.137). Female participants had higher median ACA width variable measurements than male participants for both the nasal and temporal ACAs (p ≥ 0.029). Emmetropes and hyperopes had the lowest corneal thickness and ACA width variable measurements respectively. The anterior segment variables were inversely correlated with spherical equivalent refraction (p ≤ 0.003) although the correlation coefficients were relatively weak (range between 0.111 and 0.222). The CCT was the most important anterior segment variable, with a cut-off value of 527 μm, to influence IOP in the unpruned and pruned regression tree models. The other important variables included the average peripheral corneal thickness, axial anterior chamber depth and average paracentral corneal thickness. The clinical biometric guideline presents the normal reference intervals as well as the associated 95% confidence intervals for the corneal thickness and ACA width variables in a healthy South African young adult population. The normal reference interval for the CCT measurement ranged from 434 μm to 566 μm. In the present study, the mean, range and normal reference interval for the CCT measurement differed when compared with the measurements reported in other studies involving healthy African samples living within the African continent. Conclusion: This study demonstrated that anterior segment variable measurements in a South African young adult population differ when compared with studies involving Caucasian, Asian and other African sub-populations globally. Consequently, the clinical biometric guideline with normal reference intervals therein should be used by eye care personnel when examining South African individuals. Moreover, the possible influences of demographic and/or ocular factors should be considered when evaluating anterior segment variable measurements.
Contribution of refractive errors to vision impairment in the Ashanti Region, Ghana.
(2014) Afari, Clement.; Naidoo, Kovin Shunmugam.; Amedo, Angela O.
Purpose: To determine the prevalence and causes of vision impairment with particular emphasis on uncorrected refractive error (URE) in Ashanti region, Ghana. A baseline vision impairment study in the Ashanti region is necessary to effectively plan for refractive services and blindness prevention strategies. Methods: A cross-sectional multistage cluster sampling was conducted in 24 communities in Ashanti region, Ghana. A total of 1420 participants aged 18 years and above were enumerated using a modified Rapid Assessment of Vision impairment (RAVI) protocol. This was limited to unaided visual acuity (VA) using a Snellen chart at a distance of 6 meters, near binocular visual acuity and direct ophthalmoscopy for all participants after obtaining an informed consent. The VA was repeated using a pinhole for participants with VA ≤ 6/12. A non-cycloplegic refraction was done for those whose pinhole VA improved. Near vision refraction was also assessed for each participant whose near vision was less than N8. Simple proportions were used to compute the prevalence of vision impairment and refractive error in the studied population. The results were analyzed using STATA 11. Results: One thousand three hundred (1300) of those enumerated (1420), participated in the study, a response rate of 91.5%. The mean age of the participants was 46.29 (CI 95% 45.29-47.29). The minimum age was 18 years and the maximum 99 years. Prevalence of vision impairment was 16.15% (n= 210, 95% CI, 14.15 – 18.16). Refractive error was the leading cause of vision impairment with 47.14% (n = 99, 95% CI of 40.33 - 53.9) Conclusion: Refractive error was the main cause of visual loss in Ashanti region, Ghana.
Cosmetic contact lens awareness, procurement and usage amongst students at a university in Cape Town South Africa : a descriptive study.
Hendricks, Angelique Laetitia.; Moodley, Vanessa Raquel.
No abstract available.
Design, reliability and validity of a paediatric rate of reading (PRR) chart.
(2012) Nirghin, Urvashni.; Oduntan, Olalekan Alabi.
Background: Reading rate is a measure of fluency, reflecting the level of reading performance especially in children, which is not typically measured during routine eye examinations. Optometric clinical tests such as Snellen visual acuity are often poor predictors of everyday reading performance, as they test the smallest print a person is able to read rather than fluency. Conventional reading rate tests for educational purposes presents with many limitations; they concentrate on linguistic skills, increase in complexity as the reading progresses, limited by the readers vocabulary but more importantly, they do not take the level of the child's vision into consideration. There is currently no reading rate chart that is designed with optometric notations specifically for children with normal vision and low vision. It is therefore necessary to design a reading rate chart that takes the above limitations into consideration. Aim: This study aimed to design a chart that can be used to measure reading rates in normal sighted and low vision primary school children. Methods: The aim of the study was achieved in four parts; the design, reliability, validity of a reading rate chart and finally the testing of the chart on low vision participants. In the design of the chart, ten frequently used words in grade one English reading books were randomly selected from five primary schools in KwaZulu-Natal province, South Africa. The reliability and validity of the chart were established on normal sighted children, aged nine to twelve years from two primary schools in the Durban area chosen by convenience sampling method, with sample size of 100 for reliability and 100 for validity. Reliability was established with test and retest reading rates using the new chart while validity was established by determining the reading rates using new the chart and the Wilkins reading rate chart. Data were analyzed using the Paired t-test, Pearson correlation, and Bland and Altman method. Finally, the testing of the new chart without and with low vision device, on fourteen low vision children, aged eight to nineteen years, attending a school for the visually impaired in KwaZulu-Natal. Data was analyzed using Paired t-test and Pearson correlation. Results: The words were arranged in random order, ten words per row and ten rows per paragraph. The chart consisted of six paragraphs (versions A, B, C, D, E and F) with six acuity levels and four optometric notations. Each version was printed on a separate sheet, in Arial and Times New Romans fonts and printed in black ink on approximately white cardboards. In reliability, the mean test and retest reading rates were 77.65 ± 25.30 and 78.23 ± 24.70 (p = 0.29, R² = 0.95). In Bland and Altman method, the mean difference was −0.58 with confidence limits at +10.07 and -11.23. In validity, reading rate for Wilkins chart and the new chart were 75.82 ± 23.64 and 74.92 ± 23.58 (p = 0.01, R² = 0.99) respectively. In Bland-Altman method, the mean difference was +0.90, upper limit at +6.33 and lower limit at –4.53. The mean reading rate, of the low vision children, without and with the low vision device were 59.32 ± 24.08 words per minute (wpm) and 67.04 ± 25.63 words per minute (wpm) respectively (p = 0.09 and r = 0.82). Conclusions: This chart can be used for reading rate assessment for both normally sighted and low vision children and is statistically reliable and valid.
Development of an algorithmic approach for the early detection and management of keratoconus.
(2023) Masiwa, Lynett Erita.; Moodley, Vanessa Raquel.
Empirical evidence, supported by anecdotal evidence suggests that some Keratoconic pre-pubescent children present for their first clinical examinations with advanced signs of KC and visual impairment that cannotr be corrected with readily accessible optical aids. This is evidenced by higher prevalences of KC reported in some African communities. This negatively impacts on the lives of these children and hinders the practitioner’s capacity to successfully manage the patient and provide good functional vision, often resulting in visual impairment. The study set out to verify this observation and to offer a potential solution to the problem that is the late presentation of young subjects with KC residing in Harare. Method: A questionnaire, Visual acuity check, retinoscopy and anterior segment assessment were used to award subjects attending primary school in urban Harare aged 6-12years a keratoconus risk score as per scoring sheet developed. A comprehensive exam including refraction, slit lamp exam and keratometry were then performed on the high-risk subjects for the diagnosis of clinical KC. Topography, contrast sensitivity measurement and pachymetry map analysis were then performed for the diagnosis of pre-clinical KC. Results: 1159 subjects were recruited, 57% were female, 99% of African ethnicity and Christian background. Prevalence of clinical KC was found to be 630: 100 000 and pre-clinical KC was found to be 1360:100 000. Anterior surface abnormalities were present in 30% of the subjects considered to be high risk for the development of KC. The age range of the subjects diagnosed with clinical KC was 8-12years. VKC, reduced VA, itchy eyes and eye rubbing were the most frequently encountered symptoms. Conclusion: The odds of having KC are increased if the child is aged between 8 and 12 years and of African ethnicity, regardless of gender. Increased probability of developing KC was found in the presence of VKC, reduced VA, itchy eyes and frequent eye rubbing.. The early detection and management algorithm developed will allow for the timely diagnosis of KC and in turn offer improved prognosis as the earlier management of the condition will be possible with all treatment options still viable.
Development of an assessment instrument to measure disability related distress in primary school learners with vision impairment due to uncorrected refractive error in rural areas of KwaZulu-Natal Province, South Africa.
(2017) Chan, Ving Fai.; Naidoo, Kovin Shunmugam.; Singer, Susanne Katharina.
With the increasing global emphasis on improving eye health in children, numerous efforts are being implemented to meet the eye care needs of the children. There is no instrument which can be used to measure the impact of the Disability Related Distress (DRD) on children with vision impairment (VI) due to uncorrected refractive error (URE). Aim The aim of the study was to develop an assessment instrument to measure DRD in Grade 1 to Grade 5 learners with VI due to URE in a rural and semi-rural setting. Methods This mixed-method study was conducted in 4 primary schools in Pinetown, KwaZulu Natal, Durban in 3 phases. Phase 1 involved twelve focus group discussions using semi-structured interviews to identify themes that formed the DRD items in the Instrument. A topic was qualified as an item if at least two participants made substantive comments on the topic in a single focus group and the topic was discussed by at least one child in two different groups. In Phase 2, we consulted ten experts to construct an instrument for pre-testing by considering relevance, relative importance, upsetting issues and wording of the items. Issues that had a mean score < 2 for relevance or importance were excluded. In Phase 3, we pre-tested the instrument to identify missing or redundant issues. An item was included in the final instrument if the mean score of relevance was > 1.5; prevalence ratio >30% or prevalence of scores 3 or 4 >50%; range of rate of occurrence was > 2 points; no significant concerns expressed by Primary Subjects, Secondary Subjects and Tertiary Subjects, and compliance of less than 5% of the responses to the item in the debriefing session suggested that the issues were not related to VI due to URE. Results In Phase 1, thirteen children with normal vision and 63 children with VI due to URE consented to participate in the focus group discussions. Eleven themes were generated from the focus group discussions and included as items in the draft provisional list. In Phase 2, one item was excluded and the experts pointed out the need to give explanations to the children. The items included were from the domains of Loss of Self Confidence (n=3), Loss of self-worth (n=3), Loss of interconnection/ interaction with community (n=2), Suspicion, humiliation and fight (n=1) and Discrimination (n=2). In Phase 3, pre-testing was conducted on 120 children (Normal vision, NV: Mild vision impairment, MVI: Severe vision impairment, SVI: 60:30:30). The rate of occurrence of the items showed an increasing trend, from NV to MVI and SVI. The average time needed for completing the questionnaire showed an increasing trend, from NV to MVI and SVI. All eleven items in the provisional list fulfilled the retention parameters. Conclusion The developed instrument is valid, appropriate and culturally sensitive to the rural population. Its administration is resource-friendly and efficient with straightforward analysis and interpretation of data. This makes it easy to communicate the finding to a wide range of stakeholders and decision makers.
The epidemiology of ocular injuries among patients presenting to provincial hospitals in KwaZulu-Natal, South Africa.
Sukati, Velibanti Nhlanhla.; Hansraj, Rekha.
Purpose: Ocular injuries are increasingly becoming the permanent cause of visual blindness (Mufti et al, 2004). Most of the previous studies in this area are done in countries outside the African context. A limited number of general surveys in ocular trauma appear in the ophthalmic literature in South Africa. The purpose of this study was to provide epidemiological data on ocular injuries among patients utilising the provincial hospitals eye services in KwaZulu-Natal, South Africa. Methods: A quantitative retrospective study design was carried out by collecting data on 660 patient’s record cards with ocular injuries presenting to four selected provincial eye care clinics for a four year period (January 2005-December 2008). Using a data sheet devised for capturing of the information, the following data was retrieved: (i) demographics details, (ii) place of trauma (iii) nature of trauma, (iv) type of injury, (v) management and (vi) visual outcomes following primary eye care. All patients who presented to the eye clinics with ocular injuries within the specified four years, both genders, all race groups and all age groups were included in the study. Results: There were 440 patients’ records reviewed at rural hospitals and 220 at urban hospitals. Males were more likely than females to have ever experienced an eye injury (72.3% versus 27.7%, respectively) and urban males were more likely than rural males to incur an eye injury (79.1% versus 68.9%, respectively). The Black population has a higher prevalence of ocular injuries than other race groups: Blacks 93.8% followed by Indians 3.9%, Coloureds 2% and the least in Whites 0.3%. Over one-third of all the patients were between 21 and 30 years old with second highest percentage of patients being in the age category of 31 to 40 years. A significant percentage of patients were children (13.8%) up to the age of 12 years. Open globe injuries were more frequent (56.2%) than closed globe injuries (43.8%). Blunt trauma/contusion was the most frequent type of injury (35.2%). More than half of patients (50.9%) had associated ocular signs with the predominance of haemorrhages (15.9%). The majority of the patients presenting with ocular signs had incurred blunt trauma (54%). Only 3.5% of all injuries were bilateral and 96.5% were unilateral. Solid objects were responsible for more than half of the injuries (54.4%) occurring either in the home or at work, followed by assaults (24.3%) and chemical burns (6.2%). Three percent of patients’ records (n=17) had substance (alcohol) abuse documented. The home accounted for the majority of the eye injuries (60.6%) followed by the social environment (15.2%), workplace or industry (13.6%), commercial workplace and agriculture had the same number of injuries (4.1%) and sports or leisure facilities (2.4%). The home remained the single most frequent place for an injury to occur across all age groups, highest in the 21 to 30 age group (26.8%, n=107) followed by 21.3% (n=85) in the 0 to 12 age group. Thirty patients (4.5%) required surgical intervention at initial presentation. Three hundred and forty patients (51.5%) returned for follow up examination. Only 9 (9.2%) patients with initial poor vision (<6/60) achieved 6/12 or better visual acuity after treatment. In 17 (38.6%) patients, visual acuity remained the same as initial visual acuity (6/15-6/60) and got worse in 5 (7.8%) patients (<6/60). Twenty six (59.1%) patients achieved between 6/15-6/60 vision after presenting with poor vision and 59 (92.2%) remained with poor vision after treatment. Conclusion: Ocular trauma is a relatively common problem in the province of KwaZulu-Natal, occurring most frequently in young adults and males warranting presentation to the eye casualty department for treatment. Ocular trauma is usually unilateral, but can also be bilateral and this remains a significant major public health problem. People engaged in agriculture, in industry, in the home, in the social environment, in sports and people living in rural communities are at highest risk. This warrants specific, targeted, prevention measures to be put in place to minimize the incidence of visually damaging trauma.
An evaluation of a school based vision screening programme.
(1992) Shaik, Rieaz.; Bhagwanjee, Anil Mohanlal.; Turnbull, Duncan Kenneth.
The effectiveness of a vision screening programme in government schools in the Durban Functional Region under the jurisdiction of the House of Representatives was evaluated. For the purpose of the study a Comprehensive Vision Screening Programme (CVSP) was developed based on the Modified Clinical Technique (MCT) used in the Orinda Study. Of the represetative sample of 419 children assessed, the CVSP classified 85 (20.3%) as referrals. In comparison, the school health nurses referred 35 (9.6%) of the children for a complete ocular examination, 40 per cent of which were unwarranted. Analysis of the usable records showed that the school vision screening programme (SVSP) correctly categorised 307 (83.9%) of the children and incorrectly categorised 59 (16.1%) of them. The latter consisted of 3.8% over-referrals and 12.3% under-referrals. The school vision screening programme did not detect with a reasonable degree of accuracy those children with visual disorders. The effectiveness of the SVSP, as determined by the phi coefficient, was 0.35. Approximately two thirds of the children with visual disorders were not detected by the SVSP. One in every eight children classified as having no visual problem by the SVSP was an under-referral and two in every five children referred by the SVSP were over-referred. The high incorrect referral rates was attributed to the use of inappropriate screening techniques. The prevalence of visual disorders in the children was 20.3%; in boys 18.7% and 21.9% in girls. The relative risk of visual disorders in girls compared to boys was 1.2 (95% CI = 0.8 - 1.7). The prevalence of eye co-ordination disorders was 11.2%, refractive error problems 10.3%, visual acuity 4.5%, perceptual status (colour vision and stereopsis) 4.0% and organic disorders 1.2%. The binocular disorders were characterised as convergence insufficiencies and the disorders of accommodation were described as accommodative insufficiencies. Referable myopia (6.7%) was more prevalent than referable hyperopia (2.1%). Myopia was more prevalent in girls and hyperopia was more prevalent in boys. The clinical findings of the refractive error was compared to that measured by an autorefractor. The findings were remarkably similar and the study concluded that the difference between the two measures was not clinically significant. The study recommended that the MCT be used as the method of choice in school vision screening protocols.
An evaluation of the accuracy of the Moorfields Motion Displacement Test.
(2020) Chetty, Keshia.; Loughman, James.; Naidoo, Kovin Shunmugam.; Govender-Poonsamy, Pirindhavellie.
Introduction: Recent statistics report a global blind population of 32.4 million and 191 million people with vision impairment, of which more than 90% of the world’s visually impaired live in developing countries. Glaucoma, the third leading cause of blindness in Africa (after cataract), is responsible for approximately 15% of blindness in the continent, requiring early detection, but goes undiagnosed in developing countries because of lack of awareness of the disease and its effects. Screening methods are not always affordable and relatively inaccessible in most developing countries, posing a barrier to identifying people at risk of glaucoma blindness. The Humphrey’s Visual Field Analyser (HVFA), considered as the gold standard in assessing visual fields, is not suited to mass screening due to cost, portability, test time, physical testing requirements among other issues, thereby making it inconvenient for mass screening programmes. These shortcomings motivated the development of the Moorfield’s Motion Displacement Test (MMDT), a new portable visual field instrument, at the Moorfield’s Eye Hospital in London. Aim: To determine the agreement and sensitivity between the Humphrey’s Visual Field Analyser (HVFA) and the Moorfield’s Motion Displacement Test (MMDT). Methods: The study followed a comparative design based on simple random sampling, comprising two hundred and seven subjects. Of the total number of subjects included in the study, the glaucoma group comprised sixty-two subjects, whilst the control group comprised one hundred and forty-five subjects. A total of 293 eyes were included in the study, of which 94 eyes were glaucomatous (case) and 199 eyes were non-glaucomatous (control), of participants who were selected via chart review from two district hospitals in KwaZulu-Natal (KZN), South Africa; McCords Provincial Eye Hospital (case) and Prince Mshiyeni Memorial Hospital (control). Both eyes were tested using the HVFA and the MMDT instruments. All subjects were asked to complete a questionnaire prior to and after testing on both instruments. Results: Non-parametric tests were used because results were not normally distributed. The diagnostic accuracy of the MMDT was high in terms of test sensitivity (100%), but performed less well in terms of specificity (63.3% and 65.3%) for case and control participants respectively. Despite the low specificity, there was a high level of similarity and a faster testing time (for both groups) in detecting glaucomatous visual field defects on the MMDT compared with the HVFA. A significant number of participants (83.5 %) across the different race groups, preferred the MMDT over the HVFA, and found the use of the mouse over a push button to be easier (74.5% across all race groups). Majority of participants (80.5%) reported focusing on a central white dot seemed more comfortable than a central amber light and found anxiety levels reduced whilst using the MMDT. Conclusion: The high sensitivity and design advantages of the MMDT for population screening may help improve glaucoma case finding in the community, and thereby facilitate earlier treatment and better health outcomes for those affected. The specificity issue should be addressed, however, to avoid service delivery problems associated with unnecessary false positive referrals.
An evaluation of the public sector optometric service provided within the eThekwini and the surrounding health districts in KwaZulu-Natal, South Africa.
Maake, Moraka Ephraim.; Moodley, Vanessa Raquel.
No abstract available.
Impact of low vision on quality of life of patients with low vision visiting the low vision center of the Eastern Regional Hospital, Ghana.
(2017) Adamptey, Beatrice.; Naidoo, Kovin Shunmugam.; Govender-Poonsamy, Pirindhavellie.
Introduction: Low vision impacts quality of life and more so when the vision loss is severe. Persons living with low vision have reduced functionality and psychosocial well-being with the potential for high dependence on others in carrying out everyday activities. Decreased quality of life and psychosocial well-being affect both the individual and the community economically as the productive labour force is affected. Low vision may also increase morbidity and mortality. Although the relationship between low vision and quality of life has been extensively studied in other parts of the world, with documented evidence of the adverse effect of low vision on a person’s quality of life, very little has been done in Ghana to understand the specific setbacks and challenges low vision brings to the patients in spite of the fact that there are such patients living in the country for which reason a center has been set up to manage and treat them. Understanding specific vision and functional challenges is important in ensuring management that is tailored to the needs of patients with low vision. This study aims to investigate the impact of low vision on quality of life, and as well to establish the relationship between severity of vision loss and level of impact on quality of life of subjects with low vision visiting the low vision center of the Eastern Regional Hospital in Ghana. Method: A descriptive case control study involving 41 cases and 41 controls was conducted. The cases were stratified into three categories of low vision namely moderate, severe and profound. The National Eye Institute Visual Function Questionnaire (NEI VFQ-25) which consists of twenty five questions was used in the collection of data. Descriptive statistics and logistic regression analysis were conducted to determine associations between various variables. Results: Case subjects had statistically significantly lower quality of life compared to control subjects (cases, median=46.09, IQR= 30.84-66.00, n=41), (controls, median= 98.09, IQR=94.94-100.00-, n=41), p<0.001). The functional and psychosocial subscales (driving, near and distance activities, social function and mental health) produced the lowest quality of life scores. There was, however, no statistically significant difference in the ocular pain and discomfort subscale between cases and controls ((cases; median= 87.50, IQR= 71.88-100), (controls; median= 87.50, IQR= 87.50-100), p=0.098). Regression analysis showed no significant relationship between demographic profile and quality of life. Cases with profound low vision were 0.49 (95% CI= 0.46-0.71) times less likely to have good quality of life compared to subjects with normal vision. Quality of life worsened with decreasing vision Conclusion: Quality of life is impacted by low vision especially in areas of functionality and psychosocial well-being. The degree of impact of low vision on quality of life is influenced by the severity of vision loss. Incorporation of social support services counseling and rehabilitation protocols that focus on improving functionality may be a step in the right direction in assisting persons with low vision adapt to their vision loss and improve their quality of life.
The incidence and distribution of ametropia in blacks in Umlazi.
(1988) Rasengane, Tuwani A.; Simpson, T. L.; Turnbull, Duncan Kenneth.
Age, sex, race, heredity, environment and nutrition have been found to influence ametropia. In this study, the distribution of refractive errors has been investigated in relation to age, sex, race, education and near work, and lighting conditions. Visual awareness and vision screening in pre-school and schoolchildren were also investigated. Data were collected using the Nikon auto-refractor, retinoscope, Snellen V.A chart, and subjective techniques. 777 people were refracted, whose ages ranged between four and eighty years. Measurements were made in different sections of Umlazi township, therefore people of different socio-economic sectors were refracted. Four year-old children were found to be hyperopic. Hyperopia decreased and refraction shifted towards emmetropia. Myopia started to appear at the age of ten. Myopia increased until the age of twenty, and thereafter decreased slowly until the age of thirty three, where the average refraction was emmetropia. From age forty onwards, hyperopia was predominant. The incidence of high astigmatism, high hyperopia and high myopia is low in this community. Most people fall in the spherical refractive error region of between -1.000 and +1.000. The curve is leptokurtotic with highest peak around +0.250. The cylindrical error is between -0.500 and -1.000. No significant difference between sexes was found except at the fourth age group (40-51), where females are more hyperopic than males. The other sex difference is at ages ten to twelve, where females develop myopia earlier than males. Illumination plays no important role in the development of refractive errors in this community. Education and near work seem to account very little to the development of myopia. The influence of heredity on the development of ametropia was not investigated in depth. However, there is no evidence of heredity influencing the development of ametropia. There is a lack of vision screening and visual awareness.
An investigation of saccadic eye movement abnormalities in children with HIV/AIDS on highly active antiretroviral therapy.
(2013) Naicker, Nashua.; Moodley, Vanessa Raquel.
Introduction: The Human Immuno-deficiency Virus (HIV) and the consequent Acquired Immuno-Deficiency Syndrome (AIDS) have cost the lives of millions of people globally over the past 30 years since the first cases of illness appeared. Due to the overlap in areas in the brain that are damaged by the HIV with those that control saccadic eye movements, screening of eye movement functions in children with HIV/AIDS could thus be a valuable early indicator of a declining neurological and immunological state. Therefore, movement testing through non-invasive means may give the optometrist valuable insight into the developing central nervous system (CNS) in HIV-infected children. Aim: To determine if abnormal saccadic eye movements in children with HIV/AIDS on HAART could be a predictor of the status of their immune system. Methodology: The study population comprised of 128 conveniently selected subjects aged 5 to 14years diagnosed with HIV/AIDS on HAART. This prospective study, used a descriptive design. The two significant biological parameters such as CD4 count and viral load (VL) data of patients were accessed and subjects performed the DEM test, which is a visual-verbal reading speed test, used to detect oculomotor function as well as automaticity skills. The subjects were then classified according to the different „behaviour types‟ as is specified in the DEM test based on their test performances. Statistical Analysis Software (SAS) version 9.2 was used to analyse the data. Results: Nine year olds were the most prevalent comprising of 23% of the sample. Subjects were categorised into three categories of their VL and CD4 count parameters from minimal to severe immunosuppression. Seventy eight percent (78%) of subjects had minimal immunosuppression with CD4 counts ≥500cells/mm3 with a median value of 778.5 cells/mm3. Sixty five percent (65%) of the subjects had undetectable VL (<40 copies/mm3) with the median value of <40 copies/mm3 in the sample. With the DEM test, 93% had vertical and 92% had horizontal times that were outside of the standardised DEM norm. The classification of subjects into behaviour types revealed that 53% were type 3 – automaticity problems, 22% type 4 – oculomotor problems and automaticity problems, 8% type 1 – normal performance and 3% were type 2 – oculomotor dysfunction. Fourteen percent were in the unspecified behaviour type category. The relationship between the VL with behaviour types (p=0.2) and the CD4 count against the behaviour types (p=0.17) were neither statistically nor clinically significant, hence no relationship could be established. Discussion: Since the cognitive functioning in children with HIV/AIDS was moderately affected, the DEM test could be a valuable tool, if not to only detect eye movement problems but to assess the automaticity skills, which shows the impact on their neurodevelopment. It therefore does prove to be worthwhile for optometrists and other health professionals to use the DEM test as part of a battery of neurodevelopmental tests to assess different neurocognitive functions, specifically in children with HIV/AIDS. Recommendation: DEM norms for a South African paediatric population should be established as the characteristics of this population differ from the population of English-speaking American children on which this test was standardised. Conclusion: Immunologic and virologic statuses in children with HIV/AIDS on HAART cannot be predicted from abnormal saccadic eye movements. Performances across all age groups were significantly below the standard DEM norms. Saccadic eye movement abnormalities were the least prevalent and automaticity deficiencies were the most prevalent across the sample with no associations to the CD4 count and viral load.
Lifestyle and gender influence on the relationship between hypertension and intraocular pressure amongst the South Nigerian population.
(2017) Igumbor, Brenda Avwerosuo.; Nirghin, Urvashni.
Hypertension and increased intraocular pressure (IOP) have been considered to be detrimental to systemic and ocular health respectively. Untreated and prolonged increase in blood pressure (BP) has been linked to increase in IOP for some populations. Lifestyle factors such as cigarette smoking, alcohol intake, obesity, salt, fat, fruit and vegetable intake could have great influence on the relationship between hypertension and IOP. However, this has not been investigated. Aim: The aim of this study is to investigate the influence of gender and lifestyle factors on the relationship between hypertension and IOP amongst the South Nigerian population. Method: A total of 570 subjects between 20-70 years old were included in the study. Subjects were randomly selected from six approved eye hospitals within the South Nigerian region. The population was divided into two groups comprising of 285 normotensive and 285 hypertensive subjects. All subjects were presented with the information document. Only those with signed consent forms participated in the study. With each subjects, blood pressure, intraocular pressure, weight and height measurements were taken using the mercury sphygmomanometer, schiotz tonometer, measuring scale and measuring tape respectively. Thereafter, a lifestyle questionnaire about cigarette smoking, alcohol intake, obesity, salt, fat and fruit and vegetable intake were administered. Data was analyzed using the Statistical Packages for Social Sciences (Version 22), using Pearson correlation coefficient and Analysis of variance (ANOVA) Results: The percentage of male and female normotensive subjects were 33% (N=94) and 67% (N=191) respectively and served as control for the study. For the hypertensive subjects, 36.1% (N=103) were male and 63.9% (N=182) were female. The mean age was 42.31 ± 9.98 years old and 46.45 ± 10.23 years old for the normotensive and hypertensive subjects respectively. The mean IOP of the hypertensive male subjects was 21.22± 3.22 mmHg (RE) and 20.12 ± 2.62 mmHg (LE) and for the female subjects was 19.83 ± 3.75 mmHg (RE) and 18.98 ± 2.91 mmHg (LE). There was no correlation of lifestyle factors and gender on the relationship between HBP and IOP from the study. A correlation was however observed among the hypertensive subjects showing moderate correlation for SBP and DBP for IOP RE (0.375 and 0.297), respectively. A weak correlation was observed for SBP and DBP for IOP LE (0.241 and 0.204) respectively. The relationship between hypertension and IOP was statistically significant with p≤ 0.05. Conclusion: There was significant influence of gender on both hypertension and IOP for the RE and LE. Alcohol intake amongst all other lifestyle had influence on SBP, DBP and IOP RE and LE for hypertensive subjects.
Ocular health of cocoa farmers in Ghana : an assessment and intervention study.
Boadi-Kusi, Samuel Bert.; Hansraj, Rekha.; Mashige, Khathutshelo Percy.
Background: Cocoa farmers are known to face a lot of ocular health hazards such as chemicals, ultraviolet radiations, farm equipment, plants, dust and allergens among others in the field of work. This study sought to examine and understand the factors that affect the ocular health of cocoa farmers in Ghana in order to improve their knowledge and awareness on ocular health and safety practices through a training intervention. Methods: The study employed two quantitative approaches: a cross-sectional survey and a quasi- experimental pre-post-test study design. The cross-sectional study involved administration of a questionnaire and conducting a comprehensive eye examination among participants, while the pre-post-test study used a structured questionnaire to gather baseline knowledge and post training knowledge on ocular health and safety practices among the participants to establish a change. A multistage random sampling approach was used to select participants from four cocoa growing districts of Ghana. Results: Five hundred and fifty-six, out of the 576, who were recruited for the first phase of the study, met the inclusion criteria, giving an eligibility rate of 96.5%. The participants consisted of 359 (64.6%) males and 197 (35.4%) females with a mean age of 54.9 years (± 11.2). Educational attainment among the participants was low, with 142 (25.5%) having had no formal education. Participants spent an average of 33.3 (±13.4) hours per week on the farm, with males spending more time 35.3 (±13.9) than females 29.6 (± 11.8) (p<0.001) and also spent more hours on the farm than females (p<0.001). Participants reported poor distance and near vision, itching/redness, pain and tearing as major complaints. Anterior eye conditions recorded included pterygium 23.7% (CI: 20.3-27.5), allergic conjunctivitis 9.7% (CI: 7.4 - 12.5) and corneal scar/opacity 6.1% (CI: 4.3 - 8.4). Other conditions included cataract 25.5% (CI: 22.0-29.3), glaucoma 15.8 (CI: 12.9 - 19.1) and macular disorders 4.9% (CI: 3.2 - 7.0). Posterior segment conditions and uncorrected refractive errors (67.6%) were the major causes of moderate and severe visual impairment (MSVI) (16.7%) and legal blindness (4.9%) among the population studied. Presbyopia was present in 83.1% (CI: 79.7 - 86.1) of the participants. The rate of ocular injuries was 143/12 854.5 worker years or 11.3/1 000 worker years (95% CI: 9.4 - 31.0), which led to a lost work time injuries of 137 injuries/ 12 854.5 worker years or 37.3/1000 worker years (95% CI: 34.1- 40.8) and were predominantly in males. Blunt injuries from plants/branches and chemical injuries were mostly reported. Only 34 (6.1%) reported using ocular protection. Barriers to use of ocular protection included non availability of the equipment, lack of funds and ignorance or lack of training. More than half of the participants (52.4%) had never seen an eye care practitioner, while 25% reported seeking eye care within the last one year preceding the study. Those who were registered with the National Health Insurance Scheme were more likely to attend a hospital/clinic for eye care services (OR = 3.93, 1.40 - 11.06, p = 0.009). Barriers to utilization of eye facilities included lack of funds, long distance to facility and long waiting time at eye facilities. Two hundred participants enrolled for the quasi-experimented pre-post-tested study, and had varied opinions on ocular health and safety practices on the farm. They demonstrated a good knowledge on the ocular hazards they face at work, although most were unaware of the effect of some of the hazards on the eye. Farmers also had a poor knowledge on ocular protection but a fair knowledge on first aid for ocular emergencies. Participants improved their knowledge scores (overall 40 points) on ocular health and safety practices from a pre- median score of 172 (IQR: 164 - 177.5) to 212 (IQR: 206 - 219.5) following the pre- and postevaluation of the training intervention. Conclusions: Eye disorders are prevalent among cocoa farmers in Ghana. Farmers are engaged in improper ocular health and safety practices on the farm. They also make insufficient use of appropriate protective eye devices and health services. The study demonstrated that, with an ocular health intervention, cocoa farmers can improve on their knowledge and awareness level on ocular health and safety practices which may be of benefit to the farmer, employers and the national economy.
The oxygen performance of a contact lens on the human eye.
(1989) Postum, Krishnachand.; Turnbull, Duncan Kenneth.; Govinden, H. S.
There is considerable evidence to indicate that most gas permeable contact lenses do not transmit sufficient oxygen to supply all the corneal oxygen requirement. This problem is further exacerbated by non-valid methods of characterizing the oxygen performance of such lenses. The current methods of using oxygen permeability (Dk) and oxygen transmissibility (Dk/L) as indices of oxygen performance of contact lenses is completely erroneous. Dk and Dk/L pertain to contact lens materials in flat sheet form having uniform thickness and equal diffusion path at all points on the surface. Finished contact lenses, of necessity, are curved surfaces and of varying thickness. Consequently the concept of Dk and Dk/L cannot be applied to contact lenses. To date there are no studies to determine the absolute oxygen tension under gas permeable contact lenses on the human eye. All attempts to quantify the oxygen tension under a lens have been by indirect methods or by predicting the p02 from Dk values, using mathematical equations. These results do not match the clinical findings. This study was done to show that oxygen flux through a contact lens, measured in vitro, is a better determinant of the in vivo oxygen performance of gas permeable contact lenses. A special cell was designed to measure the oxygen flux, in vitro under standardised conditions. Contact lens microelectrodes were designed to measure the oxygen tension in vivo. The data obtainedwas used to develop a model for the oxygen performance of rigid gas permeable lenses on the human eye.
Patient's knowledge of diabetes, its ocular complications and management in a private practice population in the Western Cape, South Africa.
(2011) Phillips, Kevin Clyde.; Mashige, Khathutshelo Percy.; Clarke-Farr, P.
The aim of this study was to determine management regimens and level of knowledge of diabetes and its‟ ocular complications among private patients in a sample of the population of the Western Cape region of South Africa. A population-based cross-sectional study design, using purposive accidental random sampling, was used. Questionnaires completed by diabetic patients who fund their condition privately outside of the South African Public Health sector were used. One hundred and twenty-two subjects participated in the research, 66 (54%) males and 56 (46%) females. There were 73 rural and 49 urban participants. The overall sample mean BMI was 30.7, average fasting plasma glucose (FPG) 8.1 mmol/l and the majority of respondents did not perform a daily FPG test or know the significance of the HbA1c test. The majority of participants were unaware of the serious ocular consequences of prolonged hyperglycaemia. Sixty-seven percent of respondents considered that they knew enough about diabetes to manage their own condition. From the data it is apparent that private patients‟ knowledge of the systemic and ocular complications of diabetes is sub-optimal. Whilst the majority considered annual eye examinations as important, less than one-third of respondents actually undertook them. Optometrists should be offered programmes to enhance their skills and co-manage and educate diabetic patients with other health care practitioners on a formal basis. Health insurance institutions should take cognisance of the value of patient education and preventative diabetic management and incentivize patients and health care providers in this regard.

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