[Multimodal evaluation of the ocular surface using a the new Lacrydiag device]

INTRODUCTION

Dry eye disease is a very frequent condition with a significant impact on patients' quality of life. The most common clinical sign is fluorescein break up time (BUT). Recently, non-invasive measurement of BUT (NIBUT) by Placido disc analysis has been proposed to replace FBUT. We performed an automated NIBUT analysis using Lacrydiag and compared the values obtained with other typical dry eye criteria.

METHODS AND MATERIALS

A retrospective study was carried out in the Bicêtre ophthalmology department from July 1 through October 30. Dry eye patients over 18 years of age with Oxford scores>1 and OSDI scores>22 were included. They underwent slit lamp examination to determine fluorescein BUT, Oxford and Arita MGD scores. On the same day, they were tested with the Lacrydiag to assess NIBUT, tear lake height and meibography. OSDI and Schirmer's testing were performed on the date of examination. In this study, only patients' right eyes were included. The correlation between NIBUT and OSDI, Schirmer's testing and tear lake height was analyzed by Pearson's test. The correlation between NIBUT and fluorescein BUT was analysed by both Pearson and Bland-Altman statistical tests.

RESULTS

Thirty right eyes (21 women, 9 men) were included. The mean age was 62.3 years (SD 16.0), mean OSDI 49.4 (SD=20.1), mean Oxford score 3.33 (SD 2.1), mean NIBUT 6.91sec (SD 3.4), and mean FBUT 3.6sec (SD 1.8). The NIBUT and FBUT were significantly correlated (R=0.139; P=0.042), with an even more significant concordance (r=0.55; P=0.001) on Bland-Altman graphic analysis, but the mean NIBUT was 2.7 seconds higher than the FBUT (P=0.001 on Bland-Altman analysis). In addition, NIBUT was correlated with the Oxford score (R=0.156; P=0.031), but not with Schirmer I score (R=0.120; P=0.061), OSDI score (R=0.018; P=0.48), tear lake height (R=0.04; P=0.148), or Arita meibomian gland dysfunction score (R=0; P=0.933).

CONCLUSION

NIBUT is a possible alternative to FBUT for the measurement of tear film stability, with the advantage of lack of dependence on the amount of fluorescein instilled. In addition, modern imaging methods allow for automated, and thus reproducible, measurement. However, its role in the diagnostic tool kit remains to be precisely defined, especially given its weak correlation with other markers of dry eye and its significant difference from FBUT. The definitive diagnosis of dry eye thus remains based on the combined analysis of signs and symptoms.

[Ocular manifestations of viral diseases]

Les infections virales peuvent toucher l’ensemble des tuniques oculaires et mettre en jeu la fonction visuelle à plus ou moins courte terme. Les kératites et kérato-uvéites liées au virus HSV-1 sont les atteintes les plus fréquentes. Les récurrences entraînent une opacification cornéenne irréversible qui en fait la première cause de cécité d’origine infectieuse dans les pays occidentaux, et justifient un traitement antiviral préventif au long cours. Le zona ophtalmique (10 à 20 % des zonas), peut s’accompagner d’atteintes oculaires sévères (kératites, kérato-uvéites), dont 30 % deviennent chroniques/récurrentes, et de douleurs post-zostériennes, redoutables dans le territoire trigéminé. Les rétinites nécrosantes liées aux herpesvirus (HSV, VZV, CMV), sont rares mais constituent des urgences fonctionnelles absolues nécessitant un traitement antiviral par voie intraveineuse et intravitréenne. Les conjonctivites à adénovirus constituent la première cause de conjonctivite infectieuse. Le plus souvent bénignes, elles sont extrêmement contagieuses et peuvent se compliquer de lésions cornéennes invalidantes persistant plusieurs mois, voire années. Certaines arboviroses s’accompagnent de manifestations oculaires inflammatoires. Dans le cas du Zika, les infections congénitales peuvent se compliquer d’atrophie maculaire et/ou optique. Les conjonctivites sont très fréquentes à la phase aiguë de la maladie à virus Ebola, dont 15 % des survivants présentent des atteintes inflammatoires chroniques sévères liées à la persistance du virus dans les tissus uvéaux. Enfin, dans le cadre de la COVID-19, les conjonctivites ne sont pas très fréquentes mais peuvent être inaugurales, voire au premier plan et sont associées à une excrétion virale lacrymale qui doit faire prendre toutes les précautions.

[Demodex and ocular surface disease]

Demodex is a saprophytic mite of the ocular adnexa, which can in certain circumstances proliferate on the skin of the face and on the eyelid margins. It is involved in facial rosacea (especially in the papulopustular form) and in the development or aggravation of anterior and/or posterior blepharitis or even keratoconjunctivitis, often in association with cutaneous lesions ; the pathophysiology is often multifactorial. Symptoms are non-specific, but the presence of cylindrical sleeves on the eyelashes is very suggestive of infestation, and certain techniques of biomicroscopic examination or imaging, such as confocal microscopy in vivo, allow direct visualization of the parasite. Parasitological examination of the eyelashes can confirm the diagnosis and can be improved by good sampling technique. Eyelid hygiene and oil-based ointments are the cornerstone of treatment. New specific treatments, in particular topical treatments based on tea tree oil, ivermectin, as well as pulsed light therapy and micro-exfoliation of the eyelid margin, can help to reduce the parasitic load and improve symptoms.