To assess the intrarater repeatability of the measurements of tear meniscus height (TMH), noninvasive keratograph tear break-up time (NIKBUTs), and ocular redness measurements obtained with the Keratograph 5M (K5M) in a sample of soft silicone hydrogel contact lens (CL) wearers over 15 days.
Prospective study over two consecutive weeks. Three measurements of TMH, NIKBUTs (NIKBUT first and NIKBUT average), and ocular redness were obtained in different sessions; the first day (baseline, at 8 hr of wear, and after lens removal) and the last day of wear—15th day (at 8 hr of wear and after lens removal). The repeatability of measurements were assessed by two intraclass correlation coefficient (ICC) forms; single measurement [ICC (2,1)] and multiple measurements (k=3) [ICC (2, k)].
Sixty-four eyes were analyzed. The repeatability of baseline TMH [ICC (2,1) greater than 0.90; coefficient of repeatability (CR)=0.06 mm] and after and during CL wear [ICC (2,k) greater than 0.90; CR≤0.07 mm] were excellent. The repeatability of baseline NIKBUT average [ICC (2,k)=0.89 (0.82–0.93); CR=6.07 sec] was maintained after CL removal but was poorer during CL wear. The repeatability of baseline NIKBUT first [ICC (2,k) =0.80 (0.69–0.87); CR=8.74 sec] was maintained after CL removal and during CL wear at moderate–good level.
Intrarater repeatability of TMH, NIKBUTs, and ocular redness performed by K5M after CL wear remains stable when three measurements are performed. However, intrarater repeatability during CL wear decreased only for NIKBUT average and was not affected by time of use (15 days).