Methods to Measure Contrast Vision Clinical Trial
Official title:
UCST Studie 1 - Jämförande Studie Mellan några Befintliga Och Nyutvecklade Metoder för Att mäta Den Spektrala kontrastkänslighetsfunktionen Hos människa
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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Allocation: Randomized, Intervention Model: Crossover Assignment, Masking: Open Label, Primary Purpose: Diagnostic