Abstract
Purpose :
To evaluate the clinical and morphological alterations of a MGD model using chemical cauterization (CC) and to compare it with an electrocauterization (EC) model.
Methods :
The Meibomian gland (MG) orifices of both eyelids of left eye of New Zealand white rabbits (n=18) were subjected to CC using 1M NaOH (n=9) or EC (n=9), taking right eye as control. Lid margin alterations (irregularity, vascularity, plugging) and corneal surface staining was recorded at Day 7, 14, 30, 60 and 90. Tear film and MG alterations were evaluated by capturing tear meniscus height (TMH), Non-invasive tear film break-up time (NITBUT), and meibography using keratography-5M (Oculus,Wetzlar,Germany). Structural alterations in the MGs were evaluated by histopathology, immunohistochemistry, and gene expression analysis at day 7, 30 and 90 in both the groups.
Results :
The average tear film metrics at baseline were 21 ± 3.9, 0.23 ± 0.05, 14.21 ± 0.62 for Schirmer test, TMH, and NITBUT respectively. NITBUT showed significant reduction at day 30, 60 and 90 in EC group (p<0.01) and CC group (p<0.001). Lid margin vascularity, irregularity and plugging set in by day 30 in both groups, with changes being more pronounced in EC group. Corneal staining score was significantly higher at day 90 in both CC (p<0.006) and EC (p<0.008) groups. The average Meiboscore was 2.0±1.0 and 1.7±0.6 and average gland drop out score was 0.7±1.2 and 1.0±1.0 in CC and EC group respectively. Histopathological examination revealed epithelial hyperplasia, keratinization, duct dilatation and acinar atrophy in the MGs by day 30, 60 and 90 in both groups. Immunohistochemistry showed reduced expression of Cytokeratin (CK-14) suggestive of loss of epithelial meibocytes in the affected glands. Upregulated CD8+ gene expression was observed in EC compared to CC group, likely due to greater procedure induced damage by EC. Gene-expression analysis showed downregulation of epithelial cell (CK-14), proliferative stem cell (P63) and androgen receptor (AR) at Day 7, 30 and 90 in both groups (n=1 in each group).
Conclusions :
The structural and functional alterations induced by CC model were similar to EC model. Chemical cauterization can be a reliable, cost-effective, equipment independent technique to successfully induce MGD in rabbits.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.