Tear evaluation by anterior segment OCT in dry eye disease

Objective. Dry Eye Disease (DED) is a multifactorial disorder, centered by loss of tear homeostasis. The diagnosis represents a challenge in the absence of a gold standard, so different questionnaires and techniques are combined. Considering that a low lacrimal secretion and a high rate of evaporation can determine changes in the tear film, the question that arises is if there are differences between the tear film thickness and the tear meniscus values of patients with DED compared to healthy volunteers, and if so, if they can be proposed as an objective diagnosis technique using Optical Coherence Tomography (OCT). Materials and methods. Ocular Surface Disease Index (OSDI) was used together with examiner confirmation for the diagnosis of DED. All the images were acquired using anterior segment Spectral Domain - OCT. Measurements were calculated using ImageJ. IBM SPSS Statistics was used for data analysis. Statistical significance was achieved if p value was <0.05, with 95% confidence intervals. Results. There were no statistically significant differences between the two groups concerning tear film thickness for the right or left eye (p=0.895 and p=0.178, respectively, p >0.05) or the difference between them (p=0.858, p >0.05). Tear meniscus area and height for each eye and the difference between the eyes reported no significant difference between the healthy and the DED volunteers. Conclusion. Tear film thickness does not record statistically significant differences between the DED and the healthy group, and neither does the sagittal area, the tear film height, or the difference between them when acquired with OCT. Abbreviations: DED = dry eye disease, ASOCT = anterior segment optical coherence tomography, REFT = right eye tear film thickness, LEFT = left eye tear film thickness, DifFT = difference between the two eyes for tear film thickness, RETMA = right eye tear meniscus area, LETMA = left eye tear meniscus area, DifTMA = difference between the two eyes for tear meniscus area, RETMH = right eye tear meniscus height, LETMH = left eye tear meniscus height, DifTMH = difference between the two eyes for tear meniscus height.