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.
Usage note Expand. Percent is from the Latin adverbial phrase per centum meaning âby the hundred.â The Latin phrase entered English in the 16th century. Later, it was abbreviated per cent. with a final period. Eventually, the period was dropped and the two parts merged to produce the modern one-word form percent.