Assessment of Tear Film and Bulbar Redness by Keratograph 5M in Pediatric Patients After Orthokeratology.

OBJECTIVES:To assess the tear meniscus height (TMH), noninvasive tear breakup time (NITBUT), and bulbar redness in pediatric patients after orthokeratology (OK). METHODS:Pediatric patients who underwent overnight OK between December 2014 and November 2017 were retrospectively investigated. According to the time of wearing, subjects were divided into three groups: 1-week, 1-month, and over 1-year. Age-matched subjects were recruited as a control group. Keratograph 5M was used to assess TMH, NITBUT-first, NITBUT-average, and bulbar redness score. RESULTS:A total of 106 subjects aged from 7 to 15 years were included. Compared with control group, NITBUT-first was significantly lower in 1-week group (P=0.036) and NITBUT-average was significantly lower in 1-month group (P=0.019). Compared with over 1-year group, NITBUT-first was significantly lower in 1-week and 1-month groups (P=0.014, P=0.035, respectively), and NITBUT-average was significantly lower in 1-month group (P=0.022). Bulbar redness score was significantly lower in 1-month group than 1-week group (P=0.004). No significant difference in TMH was found between all groups. Significant correlation was found between NITBUT-first and NITBUT-average in all subjects (R=0.812, P<0.001). No other significant correlations were found between variables included TMH, NITBUT, bulbar redness score, or target correction. CONCLUSIONS:As a noninvasive method, Keratograph 5M was easily to be applied on pediatric patients. The OK lens did not induce significant tear deficiency or bulbar redness, but might affect tear film stability in a short term after wearing.