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This study evaluates the relative performance of different methods to measure the human spectral contrast sensitivity function (CSF).
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]].
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| Label | Type | Description | Intervention Names |
|---|---|---|---|
| UCST-V1 | Experimental | The UCST-V1 contrast sensitivity test, used to measure CSF thrice in each eye at two occasions in every treatment sequence (multi-period crossover) |
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| UCST-V2 | Experimental | The UCST-V2 contrast sensitivity test, used to measure CSF thrice in each eye at two occasions in every treatment sequence (multi-period crossover) |
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| UCST-V3 | Experimental | The UCST-V3 contrast sensitivity test, used to measure CSF thrice in each eye at two occasions in every treatment sequence (multi-period crossover) |
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| Quick-CSF | Experimental | The Quick-CSF test, used to measure CSF thrice in each eye at two occasions in every treatment sequence (multi-period crossover) |
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| Pelli-Robson | Active Comparator | The Pelli-Robson contrast sensitivity test, used to measure CSF thrice in each eye at two occasions in every treatment sequence (multi-period crossover) |
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| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| UCST-V1 | Device | A previously developed device, Uppsala Contrast Sensitivity Tester - UCST-V1, that quickly measures the human CSF in one stimulus. |
|
| 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) |
| 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] |
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Inclusion Criteria:
Exclusion Criteria:
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| Name | Role | Phone | Extension | |
|---|---|---|---|---|
| Lars Malmqvist, M.D | Contact | +46186115135 | lars.malmqvist@neuro.uu.se | |
| Gunneli Ekberg | Contact | +46186115135 |
| Name | Affiliation | Role |
|---|---|---|
| Prof. Per Söderberg, M.D PhD | Uppsala University | Principal Investigator |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| Uppsala University Hospital | Recruiting | Uppsala | 75185 | Sweden |
Anonymous or pseudo-anonymous data will be available on request or in a repository.
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| Optec 6500 | Active Comparator | The Optec 6500 contrast sensitivity test, used to measure CSF thrice in each eye at two occasions in every treatment sequence (multi-period crossover) |
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| UCST-V2 | Device | A refined version of the UCST-V1 that randomizes frequency order. |
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| UCST-V3 | Device | A version that utilises eye-tracking technology to make the measurements more accurate. |
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| Quick-CSF (QCSF) | Device | A fast contrast sensitivity measurement method using a Bayesian algorithm. |
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| Pelli-Robson | Device | A standard method developed using a Sloan-letter chart with decreasing contrast. |
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| Optec 6500 | Device | A standard test using sinusoidal gratings to measure the contrast sensitivity function. |
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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) |