Background: The coronavirus disease 2019 (COVID-19) pandemic impacted the provision of ophthalmic care.Aim: This study aimed to quantify the pandemic on the number of ophthalmic surgeries.Setting: The study was conducted at a South African tertiary academic hospital.Methods: A retrospective comparative analysis of eye surgeries 1 year pre- and post- onset of the COVID-19 lockdown (27 March 2019 to 26 March 2021) was conducted. Theatre surgical records were analysed 1-year pre- and post-lockdown. All surgical procedures were recorded and subcategorised into cataract, cornea, glaucoma, oncologic, orbital, oculoplastic, strabismus, trauma, vitreoretinal, and other. Trauma surgeries in the post-pandemic year were sub-analysed based on the level alcohol restriction level.Results: Total surgeries decreased from 3521 to 1551 (P 0.001). Using multivariate analysis, the incidence rate ratio (IRR) for all surgeries during the pandemic was 0.47 (P 0.001) with a significantly reduced IRR during the first wave of 0.427 (P = 0.003) and a non-significant change during wave two; IRR 1.25 (P = 0.36). All surgical subgroups decreased significantly except oncology, insignificant decrease from 211 to 180 (P = 0.12). Trauma significantly decreased during periods of total alcohol bans; IRR of 0.50 (P 0.001). An insignificant decrease was found during periods of partial ban with an IRR of 0.83 (P = 0.06) compared with periods without alcohol restrictions.Conclusion: Post lockdown, the total number of surgeries decreased in all subgroups except oncology. Alcohol bans significantly decreased trauma surgeries.Contribution: This article provides valuable insight, which may inform public health policy.
{"title":"Impact of the COVID-19 pandemic on ophthalmic surgery at a tertiary hospital in South Africa","authors":"Ismail Makda, A. Makgotloe, N. Ally","doi":"10.4102/aveh.v82i1.860","DOIUrl":"https://doi.org/10.4102/aveh.v82i1.860","url":null,"abstract":"Background: The coronavirus disease 2019 (COVID-19) pandemic impacted the provision of ophthalmic care.Aim: This study aimed to quantify the pandemic on the number of ophthalmic surgeries.Setting: The study was conducted at a South African tertiary academic hospital.Methods: A retrospective comparative analysis of eye surgeries 1 year pre- and post- onset of the COVID-19 lockdown (27 March 2019 to 26 March 2021) was conducted. Theatre surgical records were analysed 1-year pre- and post-lockdown. All surgical procedures were recorded and subcategorised into cataract, cornea, glaucoma, oncologic, orbital, oculoplastic, strabismus, trauma, vitreoretinal, and other. Trauma surgeries in the post-pandemic year were sub-analysed based on the level alcohol restriction level.Results: Total surgeries decreased from 3521 to 1551 (P 0.001). Using multivariate analysis, the incidence rate ratio (IRR) for all surgeries during the pandemic was 0.47 (P 0.001) with a significantly reduced IRR during the first wave of 0.427 (P = 0.003) and a non-significant change during wave two; IRR 1.25 (P = 0.36). All surgical subgroups decreased significantly except oncology, insignificant decrease from 211 to 180 (P = 0.12). Trauma significantly decreased during periods of total alcohol bans; IRR of 0.50 (P 0.001). An insignificant decrease was found during periods of partial ban with an IRR of 0.83 (P = 0.06) compared with periods without alcohol restrictions.Conclusion: Post lockdown, the total number of surgeries decreased in all subgroups except oncology. Alcohol bans significantly decreased trauma surgeries.Contribution: This article provides valuable insight, which may inform public health policy.","PeriodicalId":7694,"journal":{"name":"African Vision and Eye Health","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138962925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background: Although the benefits of intracameral mydriatics have been established in healthy patients, their safety and efficacy in difficult subjects have yet to be determined.Aim: The aim of the study is to assess the safety and efficacy of topical and intracameral application of a combination of tropicamide, phenylephrine and lidocaine during phacoemulsification surgery.Setting: The study was done at the Department of ophthalmology at the University of Bhavnagar, Gujarat, India.Methods: A total of 50 patients were recruited patients who were operated with phacoemulsification surgery. During the intraoperative period, pupil seize was studied and eventual adverse events have been monitored. Also, comfort reported by patients and surgeons has been investigated.Results: It was observed that the intracameral drug combination did not have any impact on blood pressure, pulse rate as well as did not affect the Intra Ocular Pressure (IOP) dynamics and was successful in maintaining pupil size after its application during surgery.Conclusion: The combination also proved effective as an anaesthetic agent, which was proven by pain score findings, as the patients were comfortable and compliant enough to tolerate cataract surgery.Contribution: The mydriatic and anaesthetic combination is efficient enough used topically and intracamerally to carry out phacoemulsification surgery and has a better safety profile when compared with current practices.
{"title":"A intracameral combination of tropicamide, phenylephrine and lidocaine in phacoemulsification","authors":"Dhruvil V Nayak, H. Trivedi, Ruchi Prabtani","doi":"10.4102/aveh.v82i1.844","DOIUrl":"https://doi.org/10.4102/aveh.v82i1.844","url":null,"abstract":"Background: Although the benefits of intracameral mydriatics have been established in healthy patients, their safety and efficacy in difficult subjects have yet to be determined.Aim: The aim of the study is to assess the safety and efficacy of topical and intracameral application of a combination of tropicamide, phenylephrine and lidocaine during phacoemulsification surgery.Setting: The study was done at the Department of ophthalmology at the University of Bhavnagar, Gujarat, India.Methods: A total of 50 patients were recruited patients who were operated with phacoemulsification surgery. During the intraoperative period, pupil seize was studied and eventual adverse events have been monitored. Also, comfort reported by patients and surgeons has been investigated.Results: It was observed that the intracameral drug combination did not have any impact on blood pressure, pulse rate as well as did not affect the Intra Ocular Pressure (IOP) dynamics and was successful in maintaining pupil size after its application during surgery.Conclusion: The combination also proved effective as an anaesthetic agent, which was proven by pain score findings, as the patients were comfortable and compliant enough to tolerate cataract surgery.Contribution: The mydriatic and anaesthetic combination is efficient enough used topically and intracamerally to carry out phacoemulsification surgery and has a better safety profile when compared with current practices.","PeriodicalId":7694,"journal":{"name":"African Vision and Eye Health","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139174837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Salma I.E. Hagar, Atif B.M Ali, Abd Elaziz Elmadina, S. Alrasheed, Raghda F. Mutwali
Background: Ocular dominance is used clinically for decisions on monovision in contact lens wear and treating binocular vision anomalies.Aim: This study aimed to investigate the association between macular structure and ocular dominance in normal-sighted young adult Sudanese by using optical coherence tomography (OCT).Setting: The study was conducted at Al-Neelain eye hospital, Faculty of optometry and visual sciences, Khartoum, Sudan.Methods: A prospective, cross-sectional and comparative study was conducted in 160 eyes of 80 healthy young adults. Central macular thickness (CMT), peripapillary retinal nerve fibre layer (NFL) thickness and inner retinal layers were investigated in each subject using OCT. Hole-in-the-card was used to detect ocular dominance.Results: The findings showed that the mean value of CMT for dominant eyes was slightly thicker (224.53 ± 17.18 μm) than in non-dominant eyes (224.36 ± 16.18 μm; P = 0.947). Whereas NFL thickness for dominant eyes was thicker at 31.87 ± 10.43 μm than in non-dominant 130.83 ± 10.30 μm with P = 0.528. In general, there were no highly significant differences between dominant eyes and non-dominant eyes found in macular parameters (P 0.05).Conclusion: Central macular thickness, NFL, ganglion cell layer and retinal pigmented epithelium may have some impact on determining ocular dominance in healthy adults. We believe that the exact mechanism and effects of ocular dominance remain unclear. Thus, further evaluation is needed.Contribution: This study observed slight thicker in macular parameters for the dominant eye, particularly in CMT and NFL thickness.
{"title":"Optical coherence tomography profile of macular structure and ocular dominance in young adults","authors":"Salma I.E. Hagar, Atif B.M Ali, Abd Elaziz Elmadina, S. Alrasheed, Raghda F. Mutwali","doi":"10.4102/aveh.v82i1.853","DOIUrl":"https://doi.org/10.4102/aveh.v82i1.853","url":null,"abstract":"Background: Ocular dominance is used clinically for decisions on monovision in contact lens wear and treating binocular vision anomalies.Aim: This study aimed to investigate the association between macular structure and ocular dominance in normal-sighted young adult Sudanese by using optical coherence tomography (OCT).Setting: The study was conducted at Al-Neelain eye hospital, Faculty of optometry and visual sciences, Khartoum, Sudan.Methods: A prospective, cross-sectional and comparative study was conducted in 160 eyes of 80 healthy young adults. Central macular thickness (CMT), peripapillary retinal nerve fibre layer (NFL) thickness and inner retinal layers were investigated in each subject using OCT. Hole-in-the-card was used to detect ocular dominance.Results: The findings showed that the mean value of CMT for dominant eyes was slightly thicker (224.53 ± 17.18 μm) than in non-dominant eyes (224.36 ± 16.18 μm; P = 0.947). Whereas NFL thickness for dominant eyes was thicker at 31.87 ± 10.43 μm than in non-dominant 130.83 ± 10.30 μm with P = 0.528. In general, there were no highly significant differences between dominant eyes and non-dominant eyes found in macular parameters (P 0.05).Conclusion: Central macular thickness, NFL, ganglion cell layer and retinal pigmented epithelium may have some impact on determining ocular dominance in healthy adults. We believe that the exact mechanism and effects of ocular dominance remain unclear. Thus, further evaluation is needed.Contribution: This study observed slight thicker in macular parameters for the dominant eye, particularly in CMT and NFL thickness.","PeriodicalId":7694,"journal":{"name":"African Vision and Eye Health","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139006778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Elzana Kempen, Mathys J. Labuschagne, Mpho P. Jama
{"title":"Bedside teaching in optometry: A millennial view on an ancient teaching and learning method","authors":"Elzana Kempen, Mathys J. Labuschagne, Mpho P. Jama","doi":"10.4102/aveh.v82i1.859","DOIUrl":"https://doi.org/10.4102/aveh.v82i1.859","url":null,"abstract":"","PeriodicalId":7694,"journal":{"name":"African Vision and Eye Health","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135776155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kovin S. Naidoo, Pirindhavellie Govender-Poonsamy, Priya Morjaria, Sandra Block, Ving F. Chan, Ai Chee Yong, Luigi Bilotto
Background: Vision impairment is a growing global burden issue, and appropriately trained optometrists are essential for its management. However, there is a shortage of optometrists worldwide, which hampers eye care planning. Few studies have addressed this shortage quantitatively.Aim: The study aimed to describe the distribution of the global optometric workforce.Setting: Global and country level.Methods: From February 2017 to May 2020, a standardised questionnaire in English was utilised to collect data on the global number and distribution of optometrists from key informants. Optometrists were categorised based on the World Council of Optometry’s guidelines, from levels two to four. Optometrist-to-population ratios were calculated for all countries and regions and compared with targets of 1:50 000 (in developing contexts) or 1:10 000 (in developed contexts).Results: An 80.9% response was achieved with responses from 123 of the 152 countries invited. Most (40.7%) key informants were academics. The total number of optometrists across 21 Global Burden of Disease (GBD) regions was 331 781. Sixty-six (53.7%) countries met the 1:50 000 optometrist-to-population ratio. There was a noticeable positive correlation (r = 0.7) between the prevalence of blindness and vision impairment and the optometrist-to-population ratios. Strong inverse relationships existed between a country’s gross domestic product and optometrist-to-population ratio.Conclusion: High-income countries met the target for optometrist-to-patient ratios, while low- to middle-income countries and low-income countries did not meet the targets. Low optometrist-to-patient ratios were strongly associated with a higher magnitude of blindness and vision impairment.Contribution: This article provides the first consolidation of the global optometry workforce.
{"title":"Global mapping of optometry workforce","authors":"Kovin S. Naidoo, Pirindhavellie Govender-Poonsamy, Priya Morjaria, Sandra Block, Ving F. Chan, Ai Chee Yong, Luigi Bilotto","doi":"10.4102/aveh.v82i1.850","DOIUrl":"https://doi.org/10.4102/aveh.v82i1.850","url":null,"abstract":"Background: Vision impairment is a growing global burden issue, and appropriately trained optometrists are essential for its management. However, there is a shortage of optometrists worldwide, which hampers eye care planning. Few studies have addressed this shortage quantitatively.Aim: The study aimed to describe the distribution of the global optometric workforce.Setting: Global and country level.Methods: From February 2017 to May 2020, a standardised questionnaire in English was utilised to collect data on the global number and distribution of optometrists from key informants. Optometrists were categorised based on the World Council of Optometry’s guidelines, from levels two to four. Optometrist-to-population ratios were calculated for all countries and regions and compared with targets of 1:50 000 (in developing contexts) or 1:10 000 (in developed contexts).Results: An 80.9% response was achieved with responses from 123 of the 152 countries invited. Most (40.7%) key informants were academics. The total number of optometrists across 21 Global Burden of Disease (GBD) regions was 331 781. Sixty-six (53.7%) countries met the 1:50 000 optometrist-to-population ratio. There was a noticeable positive correlation (r = 0.7) between the prevalence of blindness and vision impairment and the optometrist-to-population ratios. Strong inverse relationships existed between a country’s gross domestic product and optometrist-to-population ratio.Conclusion: High-income countries met the target for optometrist-to-patient ratios, while low- to middle-income countries and low-income countries did not meet the targets. Low optometrist-to-patient ratios were strongly associated with a higher magnitude of blindness and vision impairment.Contribution: This article provides the first consolidation of the global optometry workforce.","PeriodicalId":7694,"journal":{"name":"African Vision and Eye Health","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136317211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background: Visual impairment in children negatively impacts their learning ability compared with their normally sighted peers and the use of optical devices may in turn assist the learner in their educational pursuit.Aim: To determine the reading rate of children with low vision, with and without the use of optical devices.Setting: The study was conducted at an eye clinic in KwaZulu-Natal.Method: A pilot study was conducted on 15 children with low vision, aged between 6 years and 19 years (mean = 13.86 ± 3.34 years). Reading rate was assessed at near, using the English Paediatric Rate of Reading Test, and evaluated with and without the use of optical devices.Results: The mean reading rates were 59.32 word per minute (wpm) ± 24.08 wpm and 67.04 wpm ± 25.63 wpm without and with the optical device, respectively (p = 0.087).Conclusion: While this was a pilot study having implications on statistical significance, the results indicated an improvement in reading rate with optical devices compared with without.Contribution: Vision is integral for the efficient performance of daily tasks. Improved reading performance relates to a happier child despite their visual limitations, hence managing low vision effectively impacts scholarly progression as well as quality of life including physical, mental and social well-being of the child.
{"title":"Reading rate of low vision children using optical devices: A pilot study","authors":"Urvashni Nirghin","doi":"10.4102/aveh.v82i1.854","DOIUrl":"https://doi.org/10.4102/aveh.v82i1.854","url":null,"abstract":"Background: Visual impairment in children negatively impacts their learning ability compared with their normally sighted peers and the use of optical devices may in turn assist the learner in their educational pursuit.Aim: To determine the reading rate of children with low vision, with and without the use of optical devices.Setting: The study was conducted at an eye clinic in KwaZulu-Natal.Method: A pilot study was conducted on 15 children with low vision, aged between 6 years and 19 years (mean = 13.86 ± 3.34 years). Reading rate was assessed at near, using the English Paediatric Rate of Reading Test, and evaluated with and without the use of optical devices.Results: The mean reading rates were 59.32 word per minute (wpm) ± 24.08 wpm and 67.04 wpm ± 25.63 wpm without and with the optical device, respectively (p = 0.087).Conclusion: While this was a pilot study having implications on statistical significance, the results indicated an improvement in reading rate with optical devices compared with without.Contribution: Vision is integral for the efficient performance of daily tasks. Improved reading performance relates to a happier child despite their visual limitations, hence managing low vision effectively impacts scholarly progression as well as quality of life including physical, mental and social well-being of the child.","PeriodicalId":7694,"journal":{"name":"African Vision and Eye Health","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134908614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background: Uncorrected refractive error is an avoidable aetiology of visual impairment, negatively affecting children’s quality of life. There is limited evidence related to the prevalence of refractive errors among the children or adolescent population within Sudan. Aim: To determine the prevalence and types of refractive error among children enrolled in traditional Quranic boarding schools in the Al-Gezira state, Sudan. Setting: This cross-sectional, quantitative study conducted within the student population of traditional Quranic boarding schools in Al-Gezira, Sudan. Methods: A total of 551 male children from eight schools underwent subjective and objective refraction, including direct ophthalmoscopy as well as binocular vision assessment. Results: Out of the total 551 school children, the refractive error prevalence was 6.2% ( n = 34). The prevalence of myopia among the participants was 5.1% ( n = 28), followed by hypermetropia 1.1% ( n = 6). Astigmatism was diagnosed in 3.3% ( n = 18) of the study population classified as myopic astigmatism of 2.4% ( n = 13) and hyperopic astigmatism 0.9% ( n = 5). Conclusion: This study found the prevalence of refractive errors among the children as 6.2%. It provides baseline data about refractive error among the children in this sample, which is useful as a reference point, however further studies need to be conducted in all the Quranic schools of Sudan. Contribution: This study offers a principal information about the ametropia among the children in this community and highlights the need for further refractive errors related epidemiological studies within the region.
{"title":"Refractive error prevalence among the traditional Quranic boarding schools in Al-Gezira, Sudan","authors":"Zoelfigar D. Mohamed, Gopi S. Vankudre","doi":"10.4102/aveh.v82i1.804","DOIUrl":"https://doi.org/10.4102/aveh.v82i1.804","url":null,"abstract":"Background: Uncorrected refractive error is an avoidable aetiology of visual impairment, negatively affecting children’s quality of life. There is limited evidence related to the prevalence of refractive errors among the children or adolescent population within Sudan. Aim: To determine the prevalence and types of refractive error among children enrolled in traditional Quranic boarding schools in the Al-Gezira state, Sudan. Setting: This cross-sectional, quantitative study conducted within the student population of traditional Quranic boarding schools in Al-Gezira, Sudan. Methods: A total of 551 male children from eight schools underwent subjective and objective refraction, including direct ophthalmoscopy as well as binocular vision assessment. Results: Out of the total 551 school children, the refractive error prevalence was 6.2% ( n = 34). The prevalence of myopia among the participants was 5.1% ( n = 28), followed by hypermetropia 1.1% ( n = 6). Astigmatism was diagnosed in 3.3% ( n = 18) of the study population classified as myopic astigmatism of 2.4% ( n = 13) and hyperopic astigmatism 0.9% ( n = 5). Conclusion: This study found the prevalence of refractive errors among the children as 6.2%. It provides baseline data about refractive error among the children in this sample, which is useful as a reference point, however further studies need to be conducted in all the Quranic schools of Sudan. Contribution: This study offers a principal information about the ametropia among the children in this community and highlights the need for further refractive errors related epidemiological studies within the region.","PeriodicalId":7694,"journal":{"name":"African Vision and Eye Health","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135220106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background: Stereopsis plays a significant role in our visual system because it allows perception of depth to perform day-to-day activities. Aim: The aim of this study was to determine the severity and proportions of monocular versus binocular-induced blur on stereoacuity using the Randot ® Stereo Test (RST) at near (40 cm). Setting: Data were collected at the optometry clinic of the University of Johannesburg. Methods: The study used a cross-sectional, experimental and prospective design with a quantitative approach. Forty university students between the ages of 18 years and 25 years were invited to participate in this study. Blur was induced monocularly and binocularly through 1 dioptre (D) to 3 D lenses and stereoacuity was measured using the RST at near (40 cm). Results: Stereoacuity measured with the added 1 D to 3 D lenses monocularly and binocularly resulted in reduced stereopsis, which was worse monocularly, found not to be significant ( p = 0.17) with the addition of the 1 D lens(es) monocularly and binocularly. Significant reductions in stereoacuity were found with the addition of 2 D ( p = 0.00) and 3 D ( p = 0.00) monocularly and binocularly, respectively. Conclusion: The effect of induced optical blur monocularly on stereoacuity impacted significantly compared with induced binocular blur. However, the different accommodative amplitudes could have affected monocularly and binocularly induced stereoacuity for some participants. Contribution: The study is clinical and focuses on the effect of induced blur monocularly and binocularly on stereoacuity. Key insights are that the effect of induced optical blur monocularly impacted significantly on stereoacuity compared with induced blur binocularly.
{"title":"The effect of induced blur monocularly and binocularly on stereoacuity","authors":"Thokozile I. Metsing","doi":"10.4102/aveh.v82i1.846","DOIUrl":"https://doi.org/10.4102/aveh.v82i1.846","url":null,"abstract":"Background: Stereopsis plays a significant role in our visual system because it allows perception of depth to perform day-to-day activities. Aim: The aim of this study was to determine the severity and proportions of monocular versus binocular-induced blur on stereoacuity using the Randot ® Stereo Test (RST) at near (40 cm). Setting: Data were collected at the optometry clinic of the University of Johannesburg. Methods: The study used a cross-sectional, experimental and prospective design with a quantitative approach. Forty university students between the ages of 18 years and 25 years were invited to participate in this study. Blur was induced monocularly and binocularly through 1 dioptre (D) to 3 D lenses and stereoacuity was measured using the RST at near (40 cm). Results: Stereoacuity measured with the added 1 D to 3 D lenses monocularly and binocularly resulted in reduced stereopsis, which was worse monocularly, found not to be significant ( p = 0.17) with the addition of the 1 D lens(es) monocularly and binocularly. Significant reductions in stereoacuity were found with the addition of 2 D ( p = 0.00) and 3 D ( p = 0.00) monocularly and binocularly, respectively. Conclusion: The effect of induced optical blur monocularly on stereoacuity impacted significantly compared with induced binocular blur. However, the different accommodative amplitudes could have affected monocularly and binocularly induced stereoacuity for some participants. Contribution: The study is clinical and focuses on the effect of induced blur monocularly and binocularly on stereoacuity. Key insights are that the effect of induced optical blur monocularly impacted significantly on stereoacuity compared with induced blur binocularly.","PeriodicalId":7694,"journal":{"name":"African Vision and Eye Health","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135405186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background: Adjustment of the ocular accommodative system is an important phenomenon allowing for optimal vision at different distances. Aim: The study compared the refractive behaviour of the human eye under different ambient lighting conditions for different target brightness. Setting: Auto-refraction measurements were taken of the participants in the Department of Optometry at the University of Johannesburg. Methods: Five African participants from a single ethnic group aged between 20 years and 25 years, had 40 successive auto-refractor (Nidek AR 610) measurements taken on the right eye of each participant in a bright and dark room using the illuminated and dark targets (LL and DL); dark target in the illuminated and dark room (LD and DD). Results: A change in the refractive state of all participants was observed on LL and LD, except for one, who experienced myopic shifts. The largest significant difference in the variance-covariances and the means was approximately 2.40 dioptre (D). The other participants’ shifts in means were approximately the same and varied between 1.00 D and 1.50 D stigmatic shift. For the DL to DD conditions all participants, except for one, underwent a hyperopic shift of about 0.50 D. Conclusion: The refractive behaviour of the human eye appears to be dependent on ambient light conditions as well as target illumination or luminance. Contribution: The study is scientific and clinical, and focuses on changes in refractive behaviour under different lighting conditions, falling within the scope of the journal. Key insights are that there is a change in the refractive behaviour of the eye under different ambient conditions.
背景:调节眼调节系统是一个重要的现象，允许在不同距离的最佳视力。目的:比较人眼在不同环境光照条件下对不同目标亮度的折射行为。环境:对约翰内斯堡大学视光系的参与者进行自动折射测量。方法:5名年龄在20至25岁之间的非洲单一种族的参与者，在明亮和黑暗的房间中使用照明和黑暗的目标(左、右)对每个参与者的右眼进行40次连续的自动折射(Nidek AR 610)测量;在明亮和黑暗的房间(LD和DD)中的暗目标。结果:除1名受试者出现近视移位外，所有受试者的屈光状态均有改变。方差-协方差和平均值的最大显著差异约为2.40屈光度(D)。其他参与者的平均值变化大致相同，在1.00 D和1.50 D之间变化。对于DL到DD条件，除一人外，所有参与者都经历了约0.50 d的远视移位。结论:人眼的屈光行为似乎取决于环境光条件以及目标照明或亮度。贡献:该研究具有科学性和临床性，重点研究不同光照条件下折射行为的变化，属于该期刊的研究范围。关键的见解是，在不同的环境条件下，眼睛的折射行为会发生变化。
{"title":"The refractive behaviour of the human eye under different ambient lighting conditions","authors":"Thokozile I. Metsing, Anthony Carlson","doi":"10.4102/aveh.v82i1.839","DOIUrl":"https://doi.org/10.4102/aveh.v82i1.839","url":null,"abstract":"Background: Adjustment of the ocular accommodative system is an important phenomenon allowing for optimal vision at different distances. Aim: The study compared the refractive behaviour of the human eye under different ambient lighting conditions for different target brightness. Setting: Auto-refraction measurements were taken of the participants in the Department of Optometry at the University of Johannesburg. Methods: Five African participants from a single ethnic group aged between 20 years and 25 years, had 40 successive auto-refractor (Nidek AR 610) measurements taken on the right eye of each participant in a bright and dark room using the illuminated and dark targets (LL and DL); dark target in the illuminated and dark room (LD and DD). Results: A change in the refractive state of all participants was observed on LL and LD, except for one, who experienced myopic shifts. The largest significant difference in the variance-covariances and the means was approximately 2.40 dioptre (D). The other participants’ shifts in means were approximately the same and varied between 1.00 D and 1.50 D stigmatic shift. For the DL to DD conditions all participants, except for one, underwent a hyperopic shift of about 0.50 D. Conclusion: The refractive behaviour of the human eye appears to be dependent on ambient light conditions as well as target illumination or luminance. Contribution: The study is scientific and clinical, and focuses on changes in refractive behaviour under different lighting conditions, falling within the scope of the journal. Key insights are that there is a change in the refractive behaviour of the eye under different ambient conditions.","PeriodicalId":7694,"journal":{"name":"African Vision and Eye Health","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135424926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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