Analysis of Tear Meniscus Change after Strabismus Surgery Using Optical Coherence Tomography

ABSTRACT

PURPOSE: In this study, the changes in ocular surface parameters and tear meniscus after strabismus surgery when treated with or without artificial tears were evaluated using optical coherence tomography (OCT). METHODS: The present study included 30 patients who received bilateral lateral rectus recession surgery for exotropia. The patients instilled artificial tear eye drops only in the left eye. Before and 2, 4, 8, and 12 weeks after surgery, tear film break-up time (BUT), Schirmer's test, corneal staining test, tear meniscus height and area were measured using OCT and compared in both eyes. Before and 8 weeks after surgery, conjunctival compression cytology test was performed. RESULTS: The mean patient age was 8.7 years. After 8 weeks, BUT and corneal staining scores were 12.3 ± 1.5 seconds and 1.3 ± 0.4 in patients treated with artificial tears and 9.5 ± 1.0 seconds and 2.0 ± 0.7 in patients not treated with artificial tears (both p < 0.000). Four weeks after surgery, tear meniscus height and area using OCT were 290.2 ± 42.3 µm and 566.7 ± 48.2 pixels in patients treated with artificial tears and 246 ± 45.5 µm and 504.0 ± 29.7 pixels in patients not treated with artificial tears (p = 0.045 and p = 0.019, respectively). Goblet cell count was significantly different between the eyes 8 weeks after surgery (p = 0.033). CONCLUSIONS: Instability of tear meniscus can be detected after strabismus surgery using BUT, Schirmer's test, corneal staining test, tear meniscus height and area, and OCT. After surgery, artificial tears help treat dry eye symptoms by corneo-conjunctival wound healing mechanism and increasing tear meniscus stability.