Objective—To determine effects of atracurium on
intraocular pressure (IOP), eye position, and arterial
blood pressure in eucapnic and hypocapnic dogs
anesthetized with isoflurane.
Procedure—Ventilation during anesthesia was controlled
to maintain PaCO2 at 38 to 44 mm Hg in group-I dogs (n = 8) and 26 to 32 mm Hg in group-II dogs
(8). Baseline measurements for IOP, systolic, diastolic,
and mean arterial blood pressure, central venous
pressure (CVP), and heart rate (HR) were recorded.
Responses to peroneal nerve stimulation were monitored
by use of a force-displacement transducer.
Atracurium (0.2 mg/kg) was administered IV and measurements
were repeated at 1, 2, 3, and 5 minutes
and at 5-minute intervals thereafter for 60 minutes.
Results—Atracurium did not affect IOP, HR, or CVP.
Group II had higher CVP than group I, but IOP was not
different. There was no immediate effect of atracurium
on arterial blood pressure. Arterial blood pressure
increased gradually over time in both groups. Thirty
seconds after administration of atracurium, the eye
rotated from a ventromedial position to a central position
and remained centrally positioned until 100%
recovery of a train-of-four twitch response. The time
to 100% recovery was 53.1 ± 5.3 minutes for group I
and 46.3 ± 9.2 minutes for group II.
Conclusions and Clinical Relevance—Atracurium
did not affect IOP or arterial blood pressure in isoflurane-
anesthetized dogs. Hyperventilation did not
affect IOP or the duration of effect of atracurium. (Am
J Vet Res 2004;65:179–182)
Objective—To measure ocular effects (blood-aqueous barrier breakdown and intraocular pressure [IOP]) following aqueocentesis performed with needles of various sizes in dogs.
Animals—28 healthy adult dogs.
Procedures—24 dogs underwent unilateral aqueocentesis (24 treated eyes and 24 contra-lateral untreated eyes); 25-, 27-, or 30-gauge needles were used in 3 treatment groups (n = 8/group). Four dogs were untreated controls. Aqueocentesis was performed during sedation and topical anesthesia. Anterior chamber fluorophotometry was performed before and after aqueocentesis on day 1. On days 2 through 5, sedation and fluorophotometry were repeated. Intraocular pressure was measured with a rebound tonometer at multiple time points.
Results—Aqueocentesis resulted in blood-aqueous barrier breakdown detected via fluorophotometry in all treated eyes, with barrier reestablishment by day 5. On day 2, the contralateral untreated eyes of all 3 groups also had significantly increased fluorescence. Use of a 25-gauge needle resulted in a significant increase in treated eyes' anterior chamber fluorescence on days 3 and 5 as well as a significant increase in IOP 20 minutes following aqueocentesis, compared with the other treatment groups.
Conclusions and Clinical Relevance—Aqueocentesis performed with a 25-gauge needle resulted in the greatest degree of blood-aqueous barrier breakdown and a brief state of intraocular hypertension. Use of a 27- or 30-gauge needle is recommended for aqueous paracentesis. A consensual ocular reaction appeared to occur in dogs following unilateral traumatic blood-aqueous barrier breakdown and may be of clinical importance.
Objective—To evaluate lactoferrin and lysozyme content
in various ocular glands of bison and cattle and in
tears of bison.
Sample Population—Tissues of ocular glands
obtained from 15 bison and 15 cattle and tears collected
from 38 bison.
Procedure—Immunohistochemical analysis was
used to detect lysozyme and lactoferrin in formalin-fixed,
paraffin-embedded sections of the ocular
glands. Protein gel electrophoresis was used to analyze
ocular glands and pooled bison tears by use of a
tris-glycine gel and SDS-PAGE. Western blotting was
used to detect lactoferrin and lysozyme.
Results—Immunohistochemical staining for lactoferrin
was evident in the lacrimal gland and gland of the third
eyelid in cattle and bison and the deep gland of the third
eyelid (Harder's gland) in cattle. Equivocal staining for
lactoferrin was seen for the Harder's gland in bison. An
80-kd band (lactoferrin) was detected via electrophoresis
and western blots in the lacrimal gland and gland of
the third eyelid in cattle and bison, Harder's glands of
cattle, and bison tears. An inconsistent band was seen
in Harder's glands of bison. Lysozyme was not detected
in the lacrimal gland of cattle or bison with the use of
immunohistochemical analysis or western blots.
Western blots of bison tears did not reveal lysozyme.
Conclusion and Clinical Relevance—Distribution
of lactoferrin and a lack of lysozyme are similar in the
lacrimal gland of cattle and bison. Differences in other
tear components may be responsible for variability in
the susceptibility to infectious corneal diseases that
exists between bison and cattle. (Am J Vet Res