AIM:To determine the smartphone use patterns and effects of smartphone use on accommodation and convergence system of the eyes among Malaysian teenagers.METHODS:A total of 62 participants aged between 13 and 17y were ...AIM:To determine the smartphone use patterns and effects of smartphone use on accommodation and convergence system of the eyes among Malaysian teenagers.METHODS:A total of 62 participants aged between 13 and 17y were involved.A self-administered questionnaires containing 12 items was used to evaluate the smartphone usage patterns.This was followed by an eye examination,involving a battery of accommodation and convergence assessments before and after the smartphone use.The data analysis comprised descriptive statistics,paired t-test,and correlation coefficients.RESULTS:The use of smartphones is at a high level and at an optimal distance daily,with more than 6h a day watching video films,games,and completing school projects.Majority of the participants not reported eye strain factors and eye prescription changes with the use of digital devices.The use of a smartphone continuously for 30min was found to significantly decrease amplitude of accommodation,accommodative facility,and positive relative accommodation(P<0.001).Meanwhile,the lag of accommodation parameters and negative relative accommodation increased with the use of smartphones significantly(P<0.001).The near point of convergence(NPC)and distance and near negative fusional vergence decreased significantly(P<0.001).The NPC parameter was found to have a weak negative association with the frequency of smartphone use(R=-0.276,P<0.05).CONCLUSION:Frequent and continuous use of smartphones have increased visual stress and resulted in weakness of accommodation and vergence functions.Therefore,frequent break is mandatory when using a smartphone and appropriate visual hygiene,the 20-20-20 rule(every 20min,view something 20 feet away for 20s)are required during smartphone use to maintain visual function.展开更多
Background:To assess the influence of different spectral energy distribution on accommodation,vergence and reading performance.Methods:A Randomized experimental study was conducted after getting the approval of the Et...Background:To assess the influence of different spectral energy distribution on accommodation,vergence and reading performance.Methods:A Randomized experimental study was conducted after getting the approval of the Ethical Committee of University of Hyderabad.Forty participants with an age group of 18-21 years was integrated,out of which 50%was male and 50%was female.Subjects with emmetropia and no history of ocular pathology were included in the study.Near point of accommodation(NPA)&near point of convergence(NPC)was measured with the help of royal air force(RAF)ruler followed by near visual task of a readability passage.Results:A statistically significant result was obtained when reading rate,reading speed and NPC was compared among different spectral distribution of light(P<0.001)except NPA(P=0.43).Post hoc analysis showed a significant difference(P<0.001)when tungsten was compared with fluorescent light(FLOU),compact fluorescent light(CFL),and light emitting diode(LED)for reading rate,reading speed and NPC.But there is no noteworthy difference exist when fluorescent was compared with CFL for reading rate(P=0.530)&reading speed(P=0.595).Similarly,LED also showed no considerable difference when compared with CFL(P=0.682)and fluorescent(P=0.490)for NPC.When NPA was assessed within the group LED showed insignificant difference with CFL(P=0.205)and fluorescent(P=0.275)similar like fluorescent and tungsten(P=0.482).Conclusions:This study concluded that reading performance(reading rate and reading speed)and NPC has a significance change if we use inappropriate lighting during visual tasks.It will cause visual fatigue and strain after sustained near work.In addition,tungsten spectral energy influences the convergence which can also show an impact on reading and near visual tasks because of its brightness and miosis.Prolonged reading and working under this lighting can cause convergence disorders and visual fatigue.展开更多
Background:Spectral domain optical coherence tomography(SD-OCT)was a useful tool to study accommodation in human eye,but the maximum image depth is limited due to the decreased signal-to-noise ratio(SNR).In this study...Background:Spectral domain optical coherence tomography(SD-OCT)was a useful tool to study accommodation in human eye,but the maximum image depth is limited due to the decreased signal-to-noise ratio(SNR).In this study,improving optical resolutions,speeds and the SNR were achieved by custom built SD-OCT,and the evaluation of the impact of the improvement during accommodation was investigated.Methods:Three systems with different spectrometer designs,including two Charge Coupled Device(CCD)cameras and one Complementary Metal-Oxide-Semiconductor Transistor(CMOS)camera,were tested.We measured the point spread functions of a mirror at different positions to obtain the axial resolution and the SNR of three OCT systems powered with a light source with a 50 nm bandwidth,centered at a wavelength of 840 nm.Two normal subjects,aged 26 and 47,respectively,and one 75-year-old patient with an intraocular lens implanted were imaged.Results:The results indicated that spectrometers using cameras with 4096 camera pixels optimized the axial resolutions,due to the use of the full spectrum provided by the light source.The CCD camera system with 4096 pixels had the highest SNR and the best image quality.The system with the CMOS camera with 4096 pixels had the highest speed but had a compromised SNR compared to the CCD camera with 4096 pixels.Conclusions:Using these three OCT systems,we imaged the anterior segment of the human eye before and after accommodation,which showed similar results among the different systems.The system using the CMOS camera with an ultra-long scan depth,high resolution and high scan speed exhibited the best overall performance and therefore was recommended for imaging real-time accommodation.展开更多
目的:探讨准分子激光原位角膜磨镶术(laserin situ keratomileusis,LASIK)后近视患者调节性集合与调节比率(accommodative convergence per unit of accommodation,AC/A)变化。方法:Von Graefe法测定患者近距水平隐斜,给予+1.00D近附加...目的:探讨准分子激光原位角膜磨镶术(laserin situ keratomileusis,LASIK)后近视患者调节性集合与调节比率(accommodative convergence per unit of accommodation,AC/A)变化。方法:Von Graefe法测定患者近距水平隐斜,给予+1.00D近附加后再次测量,结果之差为梯度性AC/A比率,测量患者LASIK手术前、手术后1wk;1,3,6mo的AC/A比率,结果进行统计学分析。结果:术前戴镜AC/A比率为(2.98±0.80)△/D,手术后1wk;1,3,6mo的AC/A比率分别为(2.02±0.57)△/D,(2.43±0.63)△/D,(2.87±0.65)△/D,(2.91±0.68)△/D,手术后1wk;1mo时AC/A比率较手术前显著降低(P<0.01)。手术后3,6mo AC/A比率较手术前无差异。结论:LASIK术后1wk;1mo,AC/A比率较术前降低,术后3mo升至术前水平并稳定。展开更多
目的探讨近视患者准分子激光原位角膜磨镶术(laser in stiu keratomileusis,LASIK)后近距离工作疲劳症状及调节集合功能的变化,并分析调节集合功能对术后近距离工作疲劳症状的影响。方法选择行LASIK手术的73位患者146眼,测定术前、术后...目的探讨近视患者准分子激光原位角膜磨镶术(laser in stiu keratomileusis,LASIK)后近距离工作疲劳症状及调节集合功能的变化,并分析调节集合功能对术后近距离工作疲劳症状的影响。方法选择行LASIK手术的73位患者146眼,测定术前、术后1周、1个月、3个月时的近距离工作疲劳评分、调节幅度、正相对调节和负相对调节、调节灵活度、集合近点、调节性集合(accommodative convergence,AC)与调节(accom-modation,A)比率(AC/A),并进行统计学分析。结果 (1)近距离工作视疲劳评分在术后1周时高于术前(P<0.05),之后评分逐渐减低,术后3个月时低于术前(P<0.05)。(2)相关分析结果显示LASIK术前调节幅度及正相对调节越小、调节灵活度越差、集合近点越近、术前戴镜AC/A值越小,术后早期的近距离工作疲劳症状越明显(P<0.05);术后视疲劳症状的改善主要与调节幅度的增加、正相对调节的增加及集合近点的远离有关(P<0.05)。结论 LASIK术后早期视疲劳症状一过性加重,随着时间推移逐渐好转并较术前改善;调节与集合功能是影响LASIK术后视疲劳变化的重要因素。展开更多
文摘AIM:To determine the smartphone use patterns and effects of smartphone use on accommodation and convergence system of the eyes among Malaysian teenagers.METHODS:A total of 62 participants aged between 13 and 17y were involved.A self-administered questionnaires containing 12 items was used to evaluate the smartphone usage patterns.This was followed by an eye examination,involving a battery of accommodation and convergence assessments before and after the smartphone use.The data analysis comprised descriptive statistics,paired t-test,and correlation coefficients.RESULTS:The use of smartphones is at a high level and at an optimal distance daily,with more than 6h a day watching video films,games,and completing school projects.Majority of the participants not reported eye strain factors and eye prescription changes with the use of digital devices.The use of a smartphone continuously for 30min was found to significantly decrease amplitude of accommodation,accommodative facility,and positive relative accommodation(P<0.001).Meanwhile,the lag of accommodation parameters and negative relative accommodation increased with the use of smartphones significantly(P<0.001).The near point of convergence(NPC)and distance and near negative fusional vergence decreased significantly(P<0.001).The NPC parameter was found to have a weak negative association with the frequency of smartphone use(R=-0.276,P<0.05).CONCLUSION:Frequent and continuous use of smartphones have increased visual stress and resulted in weakness of accommodation and vergence functions.Therefore,frequent break is mandatory when using a smartphone and appropriate visual hygiene,the 20-20-20 rule(every 20min,view something 20 feet away for 20s)are required during smartphone use to maintain visual function.
文摘Background:To assess the influence of different spectral energy distribution on accommodation,vergence and reading performance.Methods:A Randomized experimental study was conducted after getting the approval of the Ethical Committee of University of Hyderabad.Forty participants with an age group of 18-21 years was integrated,out of which 50%was male and 50%was female.Subjects with emmetropia and no history of ocular pathology were included in the study.Near point of accommodation(NPA)&near point of convergence(NPC)was measured with the help of royal air force(RAF)ruler followed by near visual task of a readability passage.Results:A statistically significant result was obtained when reading rate,reading speed and NPC was compared among different spectral distribution of light(P<0.001)except NPA(P=0.43).Post hoc analysis showed a significant difference(P<0.001)when tungsten was compared with fluorescent light(FLOU),compact fluorescent light(CFL),and light emitting diode(LED)for reading rate,reading speed and NPC.But there is no noteworthy difference exist when fluorescent was compared with CFL for reading rate(P=0.530)&reading speed(P=0.595).Similarly,LED also showed no considerable difference when compared with CFL(P=0.682)and fluorescent(P=0.490)for NPC.When NPA was assessed within the group LED showed insignificant difference with CFL(P=0.205)and fluorescent(P=0.275)similar like fluorescent and tungsten(P=0.482).Conclusions:This study concluded that reading performance(reading rate and reading speed)and NPC has a significance change if we use inappropriate lighting during visual tasks.It will cause visual fatigue and strain after sustained near work.In addition,tungsten spectral energy influences the convergence which can also show an impact on reading and near visual tasks because of its brightness and miosis.Prolonged reading and working under this lighting can cause convergence disorders and visual fatigue.
基金supported by research grants from the NIH 1R21EY021336,NIH Center Grant P30 EY014801 and Research to Prevent Blindness(RPB)Department of Defense(DOD-Grant#:W81XWH-09-1-0675).
文摘Background:Spectral domain optical coherence tomography(SD-OCT)was a useful tool to study accommodation in human eye,but the maximum image depth is limited due to the decreased signal-to-noise ratio(SNR).In this study,improving optical resolutions,speeds and the SNR were achieved by custom built SD-OCT,and the evaluation of the impact of the improvement during accommodation was investigated.Methods:Three systems with different spectrometer designs,including two Charge Coupled Device(CCD)cameras and one Complementary Metal-Oxide-Semiconductor Transistor(CMOS)camera,were tested.We measured the point spread functions of a mirror at different positions to obtain the axial resolution and the SNR of three OCT systems powered with a light source with a 50 nm bandwidth,centered at a wavelength of 840 nm.Two normal subjects,aged 26 and 47,respectively,and one 75-year-old patient with an intraocular lens implanted were imaged.Results:The results indicated that spectrometers using cameras with 4096 camera pixels optimized the axial resolutions,due to the use of the full spectrum provided by the light source.The CCD camera system with 4096 pixels had the highest SNR and the best image quality.The system with the CMOS camera with 4096 pixels had the highest speed but had a compromised SNR compared to the CCD camera with 4096 pixels.Conclusions:Using these three OCT systems,we imaged the anterior segment of the human eye before and after accommodation,which showed similar results among the different systems.The system using the CMOS camera with an ultra-long scan depth,high resolution and high scan speed exhibited the best overall performance and therefore was recommended for imaging real-time accommodation.
文摘目的:探讨准分子激光原位角膜磨镶术(laserin situ keratomileusis,LASIK)后近视患者调节性集合与调节比率(accommodative convergence per unit of accommodation,AC/A)变化。方法:Von Graefe法测定患者近距水平隐斜,给予+1.00D近附加后再次测量,结果之差为梯度性AC/A比率,测量患者LASIK手术前、手术后1wk;1,3,6mo的AC/A比率,结果进行统计学分析。结果:术前戴镜AC/A比率为(2.98±0.80)△/D,手术后1wk;1,3,6mo的AC/A比率分别为(2.02±0.57)△/D,(2.43±0.63)△/D,(2.87±0.65)△/D,(2.91±0.68)△/D,手术后1wk;1mo时AC/A比率较手术前显著降低(P<0.01)。手术后3,6mo AC/A比率较手术前无差异。结论:LASIK术后1wk;1mo,AC/A比率较术前降低,术后3mo升至术前水平并稳定。
