Abstract
Purpose :
Aqueous deficiency dry eye of cicatricial etiology occur secondary to periglandular scarring obliterating the gland opening in patients with cicatrizing conjunctivitis. In order to understand the pathomechanisms and possible preventive treatment options, the current study aimed to develop a rabbit animal model of lacrimal gland damage caused by scarring conjunctivitis in the periglandular area using various techniques.
Methods :
Left eyes of New Zealand white rabbits were injected with 0.1ml of 1% NaOH in the subconjunctival plane around superior and inferior lacrimal gland orifices (after locating with fluorescein dye; Group 1, n=4), cauterization of the ductal opening (Group 2; n=4), 1% NaOH touch for 100 sec to the superior and inferior fornices with conjunctival denuding (Group 3; n=4). Nictitating membrane was removed in all groups. The ocular surface staining, Schirmer test & lacrimal gland changes were observed at baseline, week 2, 4, 8, and 12. Animals were sacrificed at 3 months from the experiment. The degree of glandular inflammation was calculated by measuring the foci (Focus = > 50 lymphocytes) in 10 high power fields (HPF).
Results :
At 12 weeks, the lacrimal glands of group 1 rabbits with periglandular injection showed severe inflammation with mean 4 foci/10HPF and reduction in the gland size. In the eyes of group 1, acinar atrophy and ductular dilatation occurred. The ocular surface staining score changed from zero to one, although tear film stability was not affected. The Schirmer value decreased by an average of 8±3.5mm (P=0.03) after 12 weeks, although it was not significantly different during the first four weeks of the experiment. No damage to the lacrimal gland or ocular surface changes were observed in groups 2 and 3, except for localized subconjunctival fibrosis seen in histology.
Conclusions :
After periglandular chemical injection, extensive damage to the lacrimal gland is observed with reduced secretion and scarring in the subconjunctival plane, whereas direct cauterization or direct chemical contact with the ductal orifices shows no such effect.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.