Abstract
Purpose :
To stablish reference intervals (RI) according to age of the morphological characteristics of the meibomian glands (MG) in healthy subjects.
Methods :
156 healthy subjects were included in the study, with a mean age and confidence interval (CI) of 43.88 (95%CI: 41.38-46.37) years, range 16-76 years. Meibography images of the upper eyelid were acquired using the Easy Tear View+® attached to a slit lamp. An image analysis software was developed in R code, consisting of 4 stages: 1) selection of the region of interest, 2) image preprocessing to obtain a binary and a skeleton image, 3) modeling of each MG to fit each MG to a piecewise linear model, and 4) quantification of the following MG features: tortuosity, superior MG area (considering only the half of the region of interest closest to the eyelid margin), number of MGs, number of segments of each MG (each MG is divided into segments according to its directional changes), deviation from a vertical line, and overall MG area. RI were calculated for each MG feature to be used as a diagnostic tool to classify a specific value as normal or non-normal. Generalized Additive Models for Location, Scale and Shape were used to estimate the percentile curve for each morphologic feature of MG, considering the influence of age and sex.
Results :
Age had an influence on tortuosity, mean=0.3 (95%CI: 0.3-0.31), RI: 0.19-0.4 < 20 years, and 0.24-0.39 at 50-60 years. Age and sex had an influence in the superior area, mean=63% (95%CI: 62-64%), mean RI: 58-74% <20 years; 59-84% >75 years; women RI: 56-71% <20 years; 57-82% >75 years. The rest of the variables were not affected by age or sex: number of MG=6.05 (95%CI: 15.28-16.82), RI: 8 -27; number of segments=6.07 (95%CI: 5.77-6.36), RI: 3-9; vertical deviation=0.37 (95%CI: 0.36-0.38), RI: 0.29-0.45, overall area=14% (95%CI: 14-15%), RI: 8.17-19.81%.
Conclusions :
It is possible to characterize the MG morphology of upper eyelid objectively. RI intervals for each of the MGs morphological characteristics were calculated considering the influence of age in tortuosity, and age and sex in superior area. These values could be useful to classify a meibography image as normal or non-normal, helping to diagnose MG alterations in an objective way.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.