The examination of the equine lacrimal gland

Abstract

ZusammenfassungDie klinische Untersuchung der Tränendrüse beim Pferd ist bisher kaum beschrieben. Ziel der vorliegenden Arbeit war es, einen systematischen, möglichst vollständigen, minimalinvasiven Untersuchungsgang für die equine Tränendrüse zu entwickeln. Die Untersuchungsschritte beinhalten Adspektion und Palpation der Tränendrüsenregion sowie die Untersuchung der Tränendrüse mittels Ultraschall (7, The examination of the equine lacrimal glandThe clinical examination of the equine lacrimal gland is only poorly documented as yet. The goal of this paper was to develop a thorough and complete clinical minimal invasive examination protocol for examination of the equine lacrimal gland. This includes inspection of the dorsotemporal region of the upper eye lid, transconjunctival palpation and ultrasonographic examination of the lacrimal gland with a 7,5 MHz probe. As further imaging techniques for the evaluation of the lacrimal gland computed tomography (CT) and magnetic resonance tomography (MRT) are described. Finally, a minimal invasive biopsy technique for the lacrimal glands was developed. Forty horses of different age, gender and breeds were subjected to an ophthalmologic examination of both eyes, and were, when ophthalmologically normal, evaluated for lacrimal gland disorders, beginning with inspection and digital palpation in the standing horse. The texture of the anterior rim of the gland could be palpated and evaluated for possible pain, swelling, and foreign body. This was followed by a transpalpebral sonographic examination of both lacrimal glands with the ultrasound probe placed on the lower eye lid and directed dorso-temporally upward. This was well tolerated by the unsedated horses. Using this technique, the mean thickness of the gland was 3.2 mm in the left, and 3.3 mm in the right eye. In two patients with thickened lacrimal glands both were more than 10 mm thick. MRT was superior to CT examination of the gland tissue, as MRT showed more details of the soft tissue structure of the gland even in its position below the bony zygomatic arch of the frontal bone. Disadvantages are the need for general anesthesia for these examinations. Furthermore, a transconjunctival biopsy technique using an 18 G (1.2 x 152 mm) soft tissue biopsy needle that was manually curved to fit to the concave ventral contour of the lacrimal glandular fossa of the bony orbit and to enable the introduction of the needle between the globe and the bony orbit. Twentyeight biopsy specimens were taken from freshly euthanatized horses and were compared with specimens of the whole lacrimal gland. It was found that the results of the histological evaluation of the biopsy specimens were comparable to those of the specimens from the whole lacrimal gland. In two patients with severe swelling of the upper eye lid and severe chronic epiphora due to a swelling of the lacrimal gland needle biopsies could successfully be obtained transconjunctively under general anesthesia, rendering transpalpebral biopsy unnecessary. Since 2008, systematic histo...

Anatomical, Histological and Histochemical Observations of the Eyelids and Orbital Glands in the Lowland Tapir (Tapirus terrestris Linnaeus, 1785) (Perissodactyla: Ceratomorpha)

“…Morphometric analysis showed that this gland in the female lowland tapirs was much larger compared to the tested superficial gland and deep gland of the third eyelid. Moreover, when comparing the dimensions of the lacrimal gland in the examined females to the measurements made in donkeys and horses, this gland was significantly smaller in lowland tapirs [44,71,[88][89][90]. Histological and histochemical studies have shown that this gland in the examined females had an acinar structure with a mucouserous nature, and in equine, this gland has a tubuloacinar structure [91] and whose secretion, as well as the superficial gland of the third eyelid, is part of the aqueous layer of the precorneal tear film [86].…”

Ultrasound, Dacryocystorhinography and Morphological Examination of Normal Eye and Lacrimal Apparatus of the Donkey (Equus asinus)

“…Our data showed that the LG appeared ovoid, and the average length was (US: 16.9 ± 1.6 mm; grossly: 25.1 ± 3.9 mm), and diameter (US: 6.1 ± 0.3 mm). The average width of the LG was 34.7 ± 4.9 mm in gross examination; whereas in horses, the LG thickness was 3.2–3.3 mm [ 40 ]. In addition, in horses, the LG measures about 5 cm transversely and 2.5–3.0 cm in the sagittal direction [ 41 , 42 , 43 ].…”