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.
A percentile is a number between 0 and 100 that shows how you rank compared to other students. It represents the percentage of students in a particular grade whose scores fall at or below your score. For example, a 10th-grade student whose Math percentile is 57 scored higher or equal to 57 percent of 10th-graders.