A Comparative Study of Six Methods to Measure Human Contrast Vision

Study Overview
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Brief Summary
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This study evaluates the relative performance of different methods to measure the human spectral contrast sensitivity function (CSF).

Detailed Description
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The human spectral contrast sensitivity function (CSF) is a better way to estimate human vision than letter charts commonly used by ophthalmologists, optometrists and opticians. The current methods used to measure the CSF are often unreliable, due to high variability between measurements. This study will compare four (4) new tests with two (2) currently used standard tests. The contrast sensitivity function will be measured using all of the six (6) methods three times (3) in each of the two (2) eyes at two (2) occasions. Each subjects CSF will be measured 6x3x2x2 = 72 times. In addition, for each of the CSF measurements, the time used to measure the CSF and number of background variables for the subjects will be recorded. After informed consent is obtained, the subjects will undergo a visual examination. If they match the inclusion criteria they will be included. At that time or at their earliest possible convenience, their CSF will be measured using the six methods and some background information will be recorded. The follow-up measurement occasion will occur between 4 to 6 weeks (28 to 42 days) after the first. To facilitate comparison with previous studies, the CSF-measurements (in rel. contrast/cycles/degree) will be converted to a log (Base 10 logarithm) scale. The unit will thus be log CSF (LCSF) [log[relative contrast]/log[cycles/per degree]].

Official Title
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UCST Studie 1 - Jämförande Studie Mellan några Befintliga Och Nyutvecklade Metoder för Att mäta Den Spektrala kontrastkänslighetsfunktionen Hos människa

Conditions
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Methods to Measure Contrast Vision

Intervention / Treatment
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* Device: UCST-V1
* Device: UCST-V2
* Device: UCST-V3
* Device: Quick-CSF (QCSF)
* Device: Pelli-Robson
* Device: Optec 6500


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Normal best corrected visual acuity: LogMAR = 0 No current or previous eye disease in either eye. Student at Uppsala University Exclusion Criteria: Previous surgery in any eye Inability to follow the test procedure.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: UCST-V1<br>The UCST-V1 contrast sensitivity test, used to measure CSF thrice in each eye at two occasions in every treatment sequence (multi-period crossover) | Device: UCST-V1<br>* A previously developed device, Uppsala Contrast Sensitivity Tester - UCST-V1, that quickly measures the human CSF in one stimulus.<br>|
| Experimental: UCST-V2<br>The UCST-V2 contrast sensitivity test, used to measure CSF thrice in each eye at two occasions in every treatment sequence (multi-period crossover) | Device: UCST-V2<br>* A refined version of the UCST-V1 that randomizes frequency order.<br>|
| Experimental: UCST-V3<br>The UCST-V3 contrast sensitivity test, used to measure CSF thrice in each eye at two occasions in every treatment sequence (multi-period crossover) | Device: UCST-V3<br>* A version that utilises eye-tracking technology to make the measurements more accurate.<br>|
| Experimental: Quick-CSF<br>The Quick-CSF test, used to measure CSF thrice in each eye at two occasions in every treatment sequence (multi-period crossover) | Device: Quick-CSF (QCSF)<br>* A fast contrast sensitivity measurement method using a Bayesian algorithm.<br>|
| Active Comparator: Pelli-Robson<br>The Pelli-Robson contrast sensitivity test, used to measure CSF thrice in each eye at two occasions in every treatment sequence (multi-period crossover) | Device: Pelli-Robson<br>* A standard method developed using a Sloan-letter chart with decreasing contrast.<br>|
| Active Comparator: Optec 6500<br>The Optec 6500 contrast sensitivity test, used to measure CSF thrice in each eye at two occasions in every treatment sequence (multi-period crossover) | Device: Optec 6500<br>* A standard test using sinusoidal gratings to measure the contrast sensitivity function.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Average time (in seconds) used to measure the contrast sensitivity function for one eye for each method |  | At end of data collection (up to 12 months after first subject is included) | 
| Average area under the curve for the log contrast sensitivity function (AULCSF) in one eye for each method | The area-under-curve of the LCSF, calculated from the measured CSF. | At end of data collection (up to 12 months after first subject is included) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sources of variability of the average time used to measure the contrast sensitivity function [seconds squared] | The factors occasion, eye, acuity, measurement order, sex,examiner will used in an ANOVA | At end of data collection (up to 12 months after first subject is included) | 
| Sources of variability of the average area under the curve for the log contrast sensitivity function [AULCSF squared] | The factors occasion, eye, acuity, measurement order, sex,examiner will used in an ANOVA | At end of data collection (up to 12 months after first subject is included) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Contrast Sensitivity, Diagnostic Techniques, Ophthalmological