Remote Based Computerized Visual Acuity Measurement
Remote Based Computerized Visual Acuity Measurement
Aim To determine the efficacy of a remotely operated computer-based logarithmic (logMAR) visual acuity chart.
Methods Visual acuity was tested using a laptop or computer-based logMAR chart (COMPlog) for all subjects by two different methods. The methods differed by the physical presence and absence (remote) of an optometrist and in the mode of instructions provided. Remote access was obtained through the internet, using Teamviewer software to control the system linked to COMPlog and instructions were provided by telephone. The order of measurements and the eye to be tested was randomised. logMAR visual acuity and time taken were recorded. A questionnaire was used to assess the participant's feedback.
Results Intraclass correlation for visual acuity between the two methods (α=0.964, 95% CI 0.937 to 0.979). There was no statistically significant difference (p=0.648) in the median visual acuity measurement between the two methods (median difference 0.00, IQR 0.20 logMAR). The time taken between the two methods was not statistically significant (p=0.457). There was no significant difference in the responses to the questionnaire between the study methods (p=0.119).
Conclusions Tele (remotely controlled) visual acuity measurement is as reliable as that measured with the physical presence of an optometrist.
Over 161 million people were visually impaired, of whom 37 million were blind across the world as at 2002. The recent estimation from the WHO shows a significant increase of approximately 285 million people being visually impaired across the world, of whom 39 million are blind. The prevalence of blindness is not distributed uniformly throughout the world—lesser developed countries have more people with blindness than developed countries. The prevalence, awareness, knowledge and uptake of facilities vary significantly between the urban and rural populations, impairing the implementation of healthcare facilities in India. Using effective screening methods to detect the at-risk population followed by a comprehensive eye examination would be an appropriate way to reduce preventable blindness. However, performing a standard vision examination on every individual is a challenging task, and factors such as the lack of infrastructure and a dearth of qualified primary eye care practitioners are the major issues.
Visual acuity is the basic and pertinent parameter needed for both the detection and management of any ocular malady. There are only 12 eye care practitioners per million population in Asia. As a result of this lack of qualified healthcare professionals, non-health professionals such as social workers, teachers and student volunteers are trained for visual acuity screening, but the validity of such screening is limited and variable. One of the solutions for cost-effective and quality eye care delivery is through tele-based eye screening in which qualified professionals perform the standard visual assessment either in real time or performing in person.
The conventional Snellen acuity chart provides unreliable visual acuity measurements and is considered to be outdated. Logarithmic (logMAR) acuity charts provide more accurate and repeatable estimates of patients' visual acuity and are the recommended modality worldwide. This could be used as an effective tool in identifying at-risk populations with refractive error and sight-threatening eye diseases such as diabetic retinopathy, macular degeneration, etc. The recent advent of computerised logMAR acuity charts are a substitute for the conventional printed chart. Therefore, we intend to determine the efficacy of a remotely operated computer-based logMAR visual acuity chart.
Abstract and Introduction
Abstract
Aim To determine the efficacy of a remotely operated computer-based logarithmic (logMAR) visual acuity chart.
Methods Visual acuity was tested using a laptop or computer-based logMAR chart (COMPlog) for all subjects by two different methods. The methods differed by the physical presence and absence (remote) of an optometrist and in the mode of instructions provided. Remote access was obtained through the internet, using Teamviewer software to control the system linked to COMPlog and instructions were provided by telephone. The order of measurements and the eye to be tested was randomised. logMAR visual acuity and time taken were recorded. A questionnaire was used to assess the participant's feedback.
Results Intraclass correlation for visual acuity between the two methods (α=0.964, 95% CI 0.937 to 0.979). There was no statistically significant difference (p=0.648) in the median visual acuity measurement between the two methods (median difference 0.00, IQR 0.20 logMAR). The time taken between the two methods was not statistically significant (p=0.457). There was no significant difference in the responses to the questionnaire between the study methods (p=0.119).
Conclusions Tele (remotely controlled) visual acuity measurement is as reliable as that measured with the physical presence of an optometrist.
Introduction
Over 161 million people were visually impaired, of whom 37 million were blind across the world as at 2002. The recent estimation from the WHO shows a significant increase of approximately 285 million people being visually impaired across the world, of whom 39 million are blind. The prevalence of blindness is not distributed uniformly throughout the world—lesser developed countries have more people with blindness than developed countries. The prevalence, awareness, knowledge and uptake of facilities vary significantly between the urban and rural populations, impairing the implementation of healthcare facilities in India. Using effective screening methods to detect the at-risk population followed by a comprehensive eye examination would be an appropriate way to reduce preventable blindness. However, performing a standard vision examination on every individual is a challenging task, and factors such as the lack of infrastructure and a dearth of qualified primary eye care practitioners are the major issues.
Visual acuity is the basic and pertinent parameter needed for both the detection and management of any ocular malady. There are only 12 eye care practitioners per million population in Asia. As a result of this lack of qualified healthcare professionals, non-health professionals such as social workers, teachers and student volunteers are trained for visual acuity screening, but the validity of such screening is limited and variable. One of the solutions for cost-effective and quality eye care delivery is through tele-based eye screening in which qualified professionals perform the standard visual assessment either in real time or performing in person.
The conventional Snellen acuity chart provides unreliable visual acuity measurements and is considered to be outdated. Logarithmic (logMAR) acuity charts provide more accurate and repeatable estimates of patients' visual acuity and are the recommended modality worldwide. This could be used as an effective tool in identifying at-risk populations with refractive error and sight-threatening eye diseases such as diabetic retinopathy, macular degeneration, etc. The recent advent of computerised logMAR acuity charts are a substitute for the conventional printed chart. Therefore, we intend to determine the efficacy of a remotely operated computer-based logMAR visual acuity chart.