Comparative Study of Two Infrared Meibographers in Evaporative Dry Eye Versus Nondry Eye Patients

Abstract

To compare the measurement of the meibomian gland (MG) dropout between two infrared meibographers in patients with and without dry eye. Methods: The right eyelids of each patient were imaged using the Antares and Cobra meibography devices. All images were analyzed using Phoenix software to calculate the percentage of the MG dropout. Lipid layer thickness, eyelid margin characteristics, ocular surface staining, MG secretion, number of expressible glands, and noninvasive tear breakup time were also evaluated. A comparison between nondry eye and evaporative dry eye was performed. Results: Eighty participants (mean age, 36.93 years and 51.3% women) were included, of which 67.5% had nondry eye. A significant difference was observed in the dropout percentage of the superior eyelid between the Antares and Cobra devices (P¼0.007) for all participants and when only the nondry eye patients were examined. In patients with dry eye, no significant differences were found in the dropout measurements of both eyelids. Conclusions: Statistically significant differences in the MG dropout percentage in the upper eyelid of nondry eye patients were obtained from both meibographers. The measurements were similar in patients with dry eye, suggesting that the two instruments can be interchanged.

Repeatability and reproducibility of Cobra HD fundus camera meibography in young adults with and without symptoms of dry eye

“…Infrared meibographers allow observation 10 and in vivo evaluation of the MG morphology, 11 which is useful for both documentation and follow‐up 3 …”

“…Several noncontact infrared meibographers are currently available. The OCULUS Keratograph 5 M (OCULUS, Inc., http://us.oculus.de) 11 employs ImageJ software (http://imagej.nih.gov) for general image analysis to provide the area of a zone marked by the user 12 . The examiner marks the zones of the everted eyelid and the MGs, and the software provides the area of each zone.…”

“…The examiner subsequently calculates MG loss by subtraction 12 . However, the two manual steps in this procedure can introduce substantial examiner bias 11 . Despite this, the OCULUS Keratograph 5 M has been reported to have good inter‐examiner reproducibility (IER; mean difference between examiners of 0.08 ± 0.55 and 0.13 ± 0.50 grade units in two separate sessions, respectively) with low within‐subject variability (WSV; 95% limits of agreement for two different examiners of −1.02 to +1.10 and −1.27 to +1.09 grade units, respectively) 13 …”

“…Alternatively, the Cobra HD (http://csoitalia.it) nonmydriatic digital fundus camera 11 uses Phoenix semi‐automated software, which is specially designed for MG analysis 14 and employs a ‘vectorised’ tool with Beziers curves that adapt rapidly to the eyelid shape 12 . Thus, the Phoenix semi‐automated software is both quicker and better than the rough segmentation obtained with ImageJ free‐hand selection 12 .…”

“…The Cobra HD meibographer has been used previously by at least four research groups in the evaluation of MG morphology 11,15–17 . In most cases, the standard deviations were quite high with respect to the mean measurement 15–17 .…”