Purpose: To visualize and describe the morphologic appearance of lid-parallel conjunctival folds (LIPCOFs) by using optical coherence tomography (OCT) and to relate it to dry eye signs and symptoms.
Methods: The LIPCOF grade, noninvasive tear film breakup time (NIBUT), lipid layer interference pattern, and dry eye symptoms were recorded in 17 normal subjects and 33 patients with dry eye. LIPCOFs were evaluated with a slit lamp and visualized by OCT. Three different algorithms for OCT were developed to grade LIPCOFs according to tear meniscus height or the covering tear film on the folds.
Results: The three OCT methods showed significant correlation with the slit lamp method (r = 0.470-0.473, P < 0.01). The OCT LIPCOF imaging methods were independent of NIBUT. The Dry Eye Questionnaire (DEQ) scores correlated with the height of the folds and the absence of tear film coverage of the folds (r = 0.574, P < 0.001 and r = -0.527, P < 0.001, respectively). The OCT LIPCOF grades correlated with the DEQ scores (r = 0.494, P < 0.001 and r = 0.310, P = 0.029, respectively). The slit lamp grade did not correlate with the DEQ scores in the whole population, but did in the normal group (r = 0.458, P = 0.024). The OCT LIPCOF grades showed inverse correlation with lipid pattern in the normal group (r = -0.422-0.481, P = 0.05); however, this association disappeared in the dry eye group.
Conclusions: OCT enabled a noninvasive, high-resolution method of imaging, evaluating, and classifying LIPCOFs. These new classifications correlated well with the slit lamp grade and the DEQ scores, promising a new, more objective evaluation of dry eye.