Rear 4-minute Schirmer Test, A Modified Indicator of Schirmer Test in Diagnosing Dry Eye

Abstract This study was desgined to find a reliable and convenient indicator (a modified Schirmer test) to improve the accuracy of assessing tear secretion and diagnosing dry eye. This is a prospective continuous study on 180 volunteers. Schirmer test I without anesthesia was performed once on both eyes to determine the value of normal Schirmer test. The values of tear secretion were recorded in each minute. Examined individuals also underwent other examinations: the standard patient evaluation of eye dryness (SPEED), the Ocular Surface Disease Index (OSDI), fluorescein stain, tear film breakup time (BUT), and Meibomian gland (MG)grading. The participants were divided into two groups: dry eye (DE) groupand non-dry eye (ND) group. The mean age was 39.41±14.05 years in DE group and 37.62±13.17 in ND group. The value of 2-minute Schirmer test, rear 3-minute Schirmer test, rear 4-minute Schirmer test and 5-minute Schirmer test was 5.36±4.63, 5.57±2.11, 7.21±4.13 and 10.93±6.30 respectively in DE group. And these indicators was 8.25±6.80, 2.73±2.31, 7.36±3.42, 11.84±6.16 in ND group. The rear 4-minute ST has significant correlation with OSDI and SPEED in DE group (r =-0.242/-0.183) and in ND gruop(r =-0.316 /-0.373). Meanwhile, rear 4-minute ST had stronger connection with fBUT(r =0.159) and MG (r =-0.162) in DE gruop. And rear 4-minute ST also had higher accuracy in diagnosing severe dry eye and borderline dry eye.The rear 4-minute Schirmer test may be a supplement indicator in assessing tear secretion and diagnosing dry eye.