Lid-parallel conjunctival fold (LIPCOF) morphology imaged by optical coherence tomography and its relationship to...

Lid-parallel conjunctival folds (LIPCOF) are a well-accepted clinical sign in dry eye diagnosis. Commonly, LIPCOF is classified by grading the number of folds observed by slit-lamp microscope. This study investigated the relationship between subjective grading scale and LIPCOF morphology imaged by optical coherence tomography (OCT).

Temporal and nasal LIPCOF of 42 subjects (mean age 27.3 ± 8.4 (SD) years; 13 M, 29 F) were observed and classified by an experienced optometrist using the Pult LIPCOF grading scale (0: no permanent, lid-parallel conjunctival fold; 1: one fold; 2: two folds, 3: three or more folds). Additionally, LIPCOF cross-sectional area (LIPCOF-A) and fold count (LIPCOF-C), as imaged by OCT (Cirrus HD; Carl Zeiss Meditec, Jena, Germany), were analysed with ImageJ 1.50 (http://rsbweb.nih.gov/ij). Correlations between subjective grading and LIPCOF-A and LIPCOF-C were analysed by Spearman correlation, differences between subjective grading and LIPCOF-C were analysed by Wilcoxon test.

For temporal and nasal sectors, mean subjective LIPCOF grade was 1.43 ± 0.86 grade units and 0.57 ± 0.80 grade units, mean LIPCOF-C was 1.67 ± 0.82 folds and 0.69 ± 0.78 folds, and mean LIPCOF-A was 0.0676 ± 0.0236mm² and 0.0389 ± 0.0352 mm², respectively. Subjective temporal and nasal LIPCOF grade was significantly correlated to LIPCOF-C (r = 0.610, p < 0.001 and r = 0.645, p < 0.001, respectively), and to LIPCOF-A (r = 0.612, p < 0.001 and r = 0.583, p < 0.001, respectively). LIPCOF-C was not statistical different to subjective LIPCOF grade (p = 0.07 and p = 0.239; temporal and nasal sectors, respectively).

OCT allows for better imaging of finer details of LIPCOF morphology, and especially of LIPCOF area. OCT evaluation of LIPCOF area correlated well with subjective grading and appears to be a promising objective method for LIPCOF classification.