Macular thickness, as measured by OCT, is one of the key outcome measures used in most clinical trials, especially those on diabetic macular edema and AMD. Because Stratus TD-OCT was the most common commercially available OCT instrument in the past decade, most trials are designed based on Stratus OCT.
A percentile (or a centile) is a measure used in statistics indicating the value below which a given percentage of observations in a group of observations fall. For example, the 20th percentile is the value (or score) below which 20% of the observations may be found. The term percentile and the related term percentile rank are often used in the reporting of scores from norm-referenced tests.
The percent value refers to the amount of light that a surface reflects relative to the amount that falls on the surface. In addition, light fixtures that are too widely spaced or wrongly positioned can create shadows. Objects between the light fixture and work being done can block the light and cast shadows.