Application of optical coherence tomography and keratograph in the measurements of lower lid margin thickness.

PURPOSE: This study aims to investigate the applicability of lower lid margin thickness (LLMT) measurements in adults with and without meibomian gland dysfunction (MGD) by optical coherence tomography (OCT) and keratograph. METHODS: This is a cross-sectional, observational study. A hundred and eight volunteers aged 20 to 79, including 68 MGD patients and 40 normal subjects, were recruited. Using OCT and keratograph to measure the LLMT from the posterior lash line to anterior edge or outer edge of the tear meniscus was separately performed two times by the same person. RESULTS: The mean age of normal and MGD subjects was 50.5 ± 14.2 years and 55.8 ± 15.5 years, respectively. The LLMT with OCT and keratograph in MGD patients was significantly greater than that in normal subjects (1.06 ± 0.27 and 1.03 ± 0.25 mm vs. 0.90 ± 0.20 and 0.86 ± 0.16 mm, respectively). In both normal and MGD subjects, the tear meniscus height and LLMT with OCT were both greater than that with keratograph (P < 0.05), and intraclass correlation coefficient (ICC) demonstrated a good agreement in the LLMT measurements between two devices (ICC = 0.83 and 0.79, respectively). Additionally, the LLMT in MGD patients was appeared to be positively correlated with meiboscore (rs = 0.37, P = 0.002). CONCLUSIONS: The OCT and keratograph were two reliable tools in the LLMT measurements, which may have potential applications for diagnosis and evaluation of MGD. Furthermore, we found that the LLMT measured by OCT was greater than that measured by keratograph.

[Proliferative ability and ultramicrostructure of basal limbal epithelial cells in different age group of normal subjects].

OBJECTIVE: To demonstrate the difference in proliferative ability and ultramicrostructure of basal limbal epithelial cells in different age group of normal subjects. METHODS: It is a case-control study.40 specimens of limbus from 40 eyes provided by the eye bank of Eye Ear Nose and Throat Hospital of Fudan University in 2007 - 2008 were enrolled in this study. Only one eye was enrolled from the same donner. Specimens were divided into 4 groups according to the donners' age: A (0 - 19 years), B (20 - 39 years), C (40 - 59 years) and D (60 - 79 years). Immunohistochemistry of proliferating cell nuclear antigen (PCNA) was performed on 10 specimens of each group. The staining status of limbal epithelium was observed and the staining positive rate of the limbal basal epithelial cells was graded. And transmission electric microscopy was performed on specimens of each group. The morphologic feature of the ultramicrostructure of limbal basal epithelial cells were observed. RESULTS: 50% of specimens in group A showed a strong PCNA staining of (++++), while a weak staining of (+) took a main part in all the other 3 groups (B 40%, C 60% and D 50%, respectively). Furthermore, positive nuclear staining of limbal superficial cells was observed in 3 specimens and positive cytoplasm staining was observed in 1 specimen, all in group A. Transmission electric microscopy showed that the stem cell-like cells in group A possessed 3 morphologic features: extremely small, stretching along the basal membrane, with densely packed heterochromatin. In contrast, the stem cell-like cells in the other 3 groups did not show great disparity in cell size with their neighbor epithelial cells, and they stretched vertically to the basal membrane, with dispersed euchromatin. CONCLUSION: Difference in proliferative ability and ultramicrostructure of basal limbal epithelial cells was found in different age group of normal subjects.