The study was conducted to evaluate tear film stability and tear secretion before and after laser in situ keratomileusis.
MATERIALS AND METHODS:
It was a prospective, longitudinal and non-comparative analysis of clinical data of 20 consecutive myopic patients (40 eyes) collected before and after laser in situ keratomileusis. Assessments included tear secretion (Schirmer I and II), fluorescein tear break up time and ocular surface staining. Statistics: The statistical package for social science (SPSS 10.0) was used for data analysis. The parameters of tear secretion and tear stability were analyzed using the paired and unpaired Student t-tests.
Schirmer II was reduced at seven days (9.5 ± 4.30 mm) and one month (10.3 ± 3.06 mm, p = 0.001) after operation from the pre-operative value of 16.12 ± 3.90 mm. Tear film stability significantly decreased at seven days (6.79 ± 3.05 sec, p Less than 0.001) and one month (8.03 ± 2.81secs, p less than 0.001) from its pre-operative value (12.68 ± 2.69 secs). 87.5% had tear film instability (FBUT less than 10secs) seven days after surgery; it was reduced to 75 % at one month and 27.5 % at three months. It was 7.5 % before surgery. Corneal staining score was increased significantly at seven days (1.42 ± 1. 58, p less than 0.01) and one month (0.95 ± 1.41, p = 0.02), from the pre-operative score of 0.17 ± 0.44.
Laser in situ keratomileusis significantly alters the tear film stability, Schirmer values and corneal staining at least for three months.
Nepal J Ophthalmol. 2011 Jul-Dec;3(2):140-5. doi: http://dx.doi.org/10.3126/nepjoph.v3i2.5266.
Shrestha GS, Wagh S, Darak A.
Institute of Medicine, Tribhuvan University, Maharajgunj, Kathmandu, Nepal. firstname.lastname@example.org