VN August 2023

Augustus 2023 37 The lacrimal caruncle is a raised nodule of conjunctiva overlying glandular tissue and is positioned medially, adjacent to the canthus. Long hairs arising from the caruncle can touch the ocular surface and irritate the eye (i.e. caruncular trichiasis;) and can also wick tear fluid away from the nasolacrimal apparatus and thereby contribute to the epiphora. Two other types of abnormal hairs are also common in brachycephalic dogs, namely distichiasis and ectopic cilia. Distichiae arise from ectopic follicles found in the eyelid margin and they protrude at the level of the lid margin through meibomian gland orifices, while an ectopic cilium comes out directly through the palpebral conjunctiva. Using in vivo confocal microscopy, it has been shown that the nerve fibre density in the corneal subepithelial and sub basal nerve plexuses is lower in brachycephalic dogs than in mesocephalic dogs. Furthermore, two separate studies of healthy canine subjects showed that central corneal sensitivity was 50%–93% Regulars I Ophthalmology Column >>>38 Macroblepharon Showing the medial entropion and fur that has resulted in pigmentary keratitis. Facial fold casuing cornreal damage Ectopic cilia