Optometry

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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.
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.
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.
Prevalence of vision conditions in a South African population of African Dyslexic children.
(2010) Wajuihian, Samuel Otabor.; Naidoo, Kovin Shunmugam.
Dyslexia is a neurological disorder with genetic origin that affects a person’s word processing ability, their spelling, writing, comprehension and reading, and results in poor academic performance. As a result, optometrists are consulted for assistance with the diagnosis and treatment of a possible vision condition. Optometrists are able to assist with treatment as part of a multidisciplinary management approach, where optometric support is necessary. International studies have indicated that up to 20% of Caucasian school children are affected by dyslexia, while there are no similar figures for African children. Studies have been done to assess the extent of visual defects among Caucasian dyslexics, but not among African dyslexic children. The aim of the study is therefore to determine the prevalence of vision conditions in an African South African population of dyslexic school children, and to investigate the relationship between dyslexia and vision. The possible relationship between dyslexia and vision conditions has been recognized as an important area of study, resulting in research being conducted in many countries. Studies have been undertaken by optometrists and ophthalmologists, who differ in their approach and attitude on how vision conditions affect dyslexia. A review of the literature revealed three broad areas of vision that may impact on reading ability, these being acuity defects, binocular vision and ocular pathology. Acuity defects consist of visual acuity and refractive error. Areas of binocular vision evaluated in the literature include near point convergence, heterophoria, strabismus, accommodative functions, vergence facility and reserves. Hyperopia was the only vision variable that was found to be consistently associated with difficulties with reading, but not causally while findings on other variables were inconclusive. However, all the studies acknowledged the complexity of the condition, and the need for a comprehensive multidisciplinary management approach for its diagnosis and management. The study was undertaken in the city of Durban, South Africa, using a case-control study of two groups of African school children between the ages of 10 and 15. Both study groups consisted of 31 children of normal intelligence, who were matched in gender, race and socio-economic status. The case group attended a school for children with learning disabilities, while the control group attended a mainstream school. At the time of the study, only one school catered for African children with learning disabilities, and only 31 of its pupils were diagnosed with dyslexia. Ethical approval was obtained from the University of KwaZulu-Natal; permission to undertake the study in the identified schools was obtained from the Department of Education, and the school principals consented on behalf of the learners, as it was not always possible to reach the individual parent. The researcher (an optometrist) visited both schools by appointment where rooms were made available to do the testing, and the tests were explained to all participants. The LogMar Acuity Charts were used to assess visual acuity, and static retinoscopy was used to assess refractive error. Binocular vision was tested using the cover test for ocular alignment, the Hirschberg test for strabismus, RAF rule for near point of convergence, ± 2 D flipper lenses for accommodation facilities, Donder’s push up methods, using the RAF rule for amplitude of accommodation, plus and minus lenses for relative accommodation, monocular estimation technique for accommodation posture, and prism bars for vergence reserves. Ocular pathology was assessed using a direct ophthalmoscope. The dyslexic group presented with the following: Refractive errors: hyperopia 6.5%, myopia 6.5%, astigmatism 10%, anisometropia 6.5%, remote near point of convergence 33%, esophoria at near 3%, exophoria at near 9.5%, accommodative infacility 54% and lag of accommodation 39.28%. The dyslexic group had relatively reduced fusional reserve compared to the control group. The control group presented with the following: Refractive errors: hyperopia 3%, astigmatism 13%, anisometropia 6.5%, remote near point of convergence 48%, esophoria at near 0%, exophoria at near 0%, accommodative infacility 33% and lag of accommodation 41.93%. The prevalence of a remote NPC was higher in the control group than in the dyslexic group and there was a statistically significant difference between the two groups: NPC break (p=0.049) and recovery (p=0.046). The prevalence of poor binocular accommodation facility at near was higher in the dyslexic group than in the control group and there was a statistically significant difference between the two groups (p = 0.027). Vision defects such as hyperopia, astigmatism, accommodation lag, convergence insufficiency, poor near point of convergence and accommodative infacility were present in the dyslexic pupils, but they were no more at risk of any particular vision condition than the control group. This study provided the prevalence of vision conditions in a population of African dyslexic children in South Africa, the only vision variable that was significantly more prevalent in the dyslexic population being the binocular accommodation facility at near, although the study was unable to find a relationship between dyslexia and vision. The statistically significant difference may not imply clinical significance due to the small sample size. However, it is recommended that any vision defects detected should be appropriately compensated for as defective vision can make reading more difficult for the dyslexic child. The sample size may have been a limitation; however, this was comparable with studies reviewed, most of which had sample sizes of less than 41. Due to the range of possible ocular conditions that could affect dyslexia, it is recommended that a larger sample size be used to ensure more conclusive results. Testing for relative accommodation with a phoropter would provide more accurate results, and accommodation facility and fusional reserves would be better assessed with suppression control. The study provides information and an indication of research needs regarding the prevalence of vision defects in an African South African population of dyslexic children.
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.
Schirmer tear test 2 and tear break-up time values in a South African young black adult population.
(2012) Khan, Naimah Ebrahim.; Oduntan, Olalekan Alabi.
Aim: The aim of this study was to establish normal values for Schirmer tear test (version 2) and tear break up time (TBUT) in a South African young adult Black population. Method: Following ethical approval by the biomedical research and ethics committee, KwaZulu-Natal, participants were recruited from the city of Durban in South Africa via personal invitations, poster advertisements and University of KwaZulu-Natal optometry clinic clients. McMonnies questionnaire for dry eye diagnosis was administered and those who failed were excluded from the main study. Two hundred (100 males and 100 females) participants who met the inclusion criteria were included in the study. Following a slit lamp examination of the eye, the Schirmer test was administered and the following day, the TBUT was measured. A re-test version of the two procedures were conducted one week after, at about the same time of the day for each subject. Results: The participants were aged 18-30 years, mean = 20.77 ± 2.29 years. The mean Schirmer test values for all participants (N = 200; 400 eyes) was 15.96 ± 6.86mm. The values for the males and females (200 eyes each) were 16.34 ± 6.93mm and 15.58 ± 6.81mm respectively. The mean TBUT (400 eyes) was 7.18 ± 1.89 secs. The mean values for the males and females (200 eyes each) were 6.90 ± 1.88 secs and 7.32 ± 1.67 secs respectively. A strong positive correlation (r = 0.895) and (r = 0.914) respectively was found between the right and left eyes in the two tests. Conclusion: Generally, the mean values found in this study for the Schirmer test are similar to those that have been reported in the literature. However, values for TBUT differ from the values that have been previously reported, being higher in some instances and lower in others. These findings have implications for dry eye diagnosis and also contact lens practice in South Africa.
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.
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.
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.
Prevalence and risk factors for Myopia among school children in Aba, Nigeria.
(2015) Atowa, Uchenna Chigozirim.; Munsamy, Alvin Jeffrey.; Wajuihian, Samuel Otabor.
Abstract available in PDF file.
Patterns of contact lens prescribing in KwaZulu-Natal.
(2015) Moodley, Veni.; Khan, Naimah Ebrahim.
Master of Medical Science in Optometry. University of KwaZulu-Natal, Durban 2015.
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.
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.
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.
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.
Visual function and quality of life in adolescents with visual impairment: a case study of the Arthur Blaxall School in Pietermaritzburg.
(2018) Naipal, Shivani.; Rampersad, Nishanee.
Background: Visual impairment (VI) may affect the lives of children, adolescents and adults although the effects of VI on the former two groups may be taken for granted as they account for less than half the population affected by VI. Affected children and adolescents may endure a lifetime of vision related difficulties that may affect their education, social interactions and possible future employment. Aim: To investigate visual function and quality of life (QoL) in adolescents with VI at the Arthur Blaxall School in Pietermaritzburg. Methods: This study followed a descriptive case study research design. Students registered at Arthur Blaxall School aged 10 years to 19 years were recruited using convenience sampling. Visual function was quantified by distance visual acuity (VA) and refractive error, contrast sensitivity, colour vision and central visual field. The QoL was assessed with the Cardiff Visual Ability Questionnaire for Children (CVAQC). Data were analysed using differential and inferential statistics. Results: The sample consisted of 70 participants with a mean age of 13.83 ± 2.28 years. The most common cause of VI was oculocutaneous albinism (OCA) followed by posterior segment disorders. The mean best-corrected VA ranged from 0.79 ± 0.16 logMAR to 0.91 ± 0.22 logMAR in the right, left and both eyes. Only 16 participants presented with spectacles and an additional 18 participants required spectacles following refraction. More than 40% of participants had moderate loss of contrast sensitivity in each eye. The majority of participants did not have any colour vision or central visual field defects. The mean visual ability score was −0.27 ± 0.74 log units, and the most difficult tasks were reading smallest print in textbooks and the board in the classroom for near and distance respectively. Participants with OCA had the best monocular best-corrected VA and contrast sensitivity. The most common colour vision defects among participants with anterior and posterior segment disorders were tritan and deutan colour vision defects respectively. Participants with anterior segment disorders had the poorest QoL while those with OCA had the best QoL. Conclusion: The results of this study showed that visual function varied among adolescents with VI. Furthermore, both visual function and QoL differed between each of the main causes of VI.
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.
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.
Reducing vision impairment in children through health system assessment and strengthening approach in Papua New Guinea.
(2018) Wabulembo, Geoffrey.; Naidoo, Kovin Shunmugam.
ABSTRACT A strong and efficient integrated health system is able to contribute to the reduction of vision impairment among children by ensuring preventive measures are implemented and timely access to care is done in case of morbidity. Children in Papua New Guinea presenting late for congenital cataract surgery, incurring avoidable eye injuries, living with uncorrected refractive error and some presenting with advanced retinoblastoma were of concern to the researcher. The overall aim of the study was to assess how the current health system in Papua New Guinea is addressing child eye health using Port Moresby General Hospital and Goroka hospital as case studies. It is envisaged that a health strengthening approach benefits children’s eye health in the community. Methods Both quantitative and qualitative methods were employed. Retrospective medical records review of children seen at the eye clinic in Port Moresby and Goroka Hospitals from January 2015 to December 2017 was conducted. In the qualitative method service providers and caregivers were interviewed to obtain their perspectives regarding performance of the health system. Results At Port Moresby General Hospital trauma, conjunctivitis and corneal ulcers accounted for 21.6%, 18.9% and 9% respectively of all the diagnoses among children. Trauma was in the ratio of 1:1 (p= 0.264) male to female. And 7.3% (n=51) of the children were blind (according to the WHO definition). Among the blind children optic nerve disorders accounted for 20.5 %( n=14) followed by both un-operated cataracts and uncorrected refractive error each at 13.2% (n=9). Retinoblastoma presented at mean age 5.869 (SD4.5) and 6.02(SD 2.4) years for girls and boys respectively. The main causes of ocular morbidity observed at Goroka Hospital were corneal ulcers (24.9%), uveitis (9.3%) and foreign bodies (9.2%). Service provider interviews revealed lack of policy on child eye health, shortage of health personnel and limited community eye health services. But among care givers lack of eye health information in the community, concerns about long waiting time at the hospitals and inadequate explanation about conditions affecting the children featured prominently. Conclusion Findings show a higher percentage of blind children compared to similar hospital based studies elsewhere. To achieve universal eye health coverage, raising awareness about child eye health needs among leaders in health is urgent. Successes registered in the past in Papua New Guinea in other child health efforts like immunisation suggest that a consistent and focused health system strengthening approach with greater integration may contribute to reduction of vision impairment among children. A proposed child eye health strategy based on the findings from this study is included in this thesis.
Refractive errors, visual impairment and utilization of spectacles among primary school children in Onitsha, Anambra State, Nigeria.
(2018) Ezinne, Ngozika Esther.; Mashige, Khathutshelo Percy.
Aim: To establish the visual status and utilization of spectacles among primary school children in Onitsha, Anambra State, Nigeria. Methods: A stratified random cluster sampling procedure was used to select children aged 5- 15 years old from grades 1 to 6 in primary schools, with 1020 children in 102 clusters being enumerated, of whom 998 (97.8%) were examined. The examination included visual acuity, retinoscopy, auto-refraction under cycloplegia, and examination of the anterior segment, media and fundus. Results: The 998 children consisted of 554 (55.5%) females and 444 (44.5%) males, with their mean age being 9.01± 2.5 years. The prevalence of uncorrected, presenting and best corrected visual acuity of 20/40 or worse in the better eye was 9.7%, 7.7% and 1.3% respectively. Refractive error accounted for 86.6% of all causes of visual impairment (best corrected visual acuity of 20/40 or worse in the better eye). Myopia was the most prevalent refractive error (46.4%), followed by astigmatism (36.1%) and hyperopia (17.5%). Myopia (of at least −0.50 D) in one or both eyes was present in 46.4% of the children when measured with retinoscopy, and 49.5% when measured with auto-refraction. Astigmatism (of –0.50DC or less) was present in 36.1% of the children when with retinoscopy and auto-refraction. Hyperopia (+2.00D or more) in at least one eye was present in 21.6% of children with auto-refraction and 17.5% with retinoscopy. Refractive error and visual impairment were significantly more prevalent in females than in males (P = 0.04).Refractive error was highest among children 11−13 year old, while visual impairment was highest among children 5−7 years old. The rate of wearing spectacles among children with visual acuity of 20/40 or worse in one or both eyes was 20.6%. The major reason for non-compliance with spectacle wear among the children was disapproval from their parents. Conclusion: The prevalence of refractive error and visual impairment among primary school children in Onitsha was high while spectacle utilization rate was low. This highlights the need for services and strategies to address refractive error, visual impairment and compliance with spectacle utilization in this region.

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