Objective—To determine whether differences exist in the calculated intraocular lens (IOL) strengths of a population of adult horses and to assess the association between calculated IOL strength and horse height, body weight, and age, and between calculated IOL strength and corneal diameter.
Animals—28 clinically normal adult horses (56 eyes).
Procedures—Axial globe lengths and anterior chamber depths were measured ultrasonographically. Corneal curvatures were determined with a modified photokeratometer and brightness-mode ultrasonographic images. Data were used in the Binkhorst equation to calculate the predicted IOL strength for each eye. The calculated IOL strengths were compared with a repeated-measures ANOVA. Corneal curvature values (photokeratometer vs brightness-mode ultrasonographic images) were compared with a paired t test. Coefficients of determination were used to measure associations.
Results—Calculated IOL strengths (range, 15.4 to 30.1 diopters) differed significantly among horses. There was a significant difference in the corneal curvatures as determined via the 2 methods. Weak associations were found between calculated IOL strength and horse height and between calculated IOL strength and vertical corneal diameter.
Conclusions and Clinical Relevance—Calculated IOL strength differed significantly among horses. Because only weak associations were detected between calculated IOL strength and horse height and vertical corneal diameter, these factors would not serve as reliable indicators for selection of the IOL strength for a specific horse.
OBJECTIVE To evaluate species differences and effects of storage duration and temperature on the anticollagenase efficacy of canine, feline, and equine serum on in vitro corneal degradation.
SAMPLES Corneas and serum from dogs, cats, and horses.
PROCEDURES Clinically normal corneas from dogs, cats, and horses were harvested within 2 hours after euthanasia. Serum samples from dogs, cats, and horses were collected and pooled by species. Corneal specimens were incubated with collagenase derived from Clostridium histolyticum, 5mM calcium chloride in saline (0.9% NaCl) solution, and feline, canine, or equine serum that had been stored for 0, 30, 90, or 180 days at −20° or −80°C. Following incubation, the corneal weight loss percentage and hydroxyproline concentration in the incubation fluid were calculated and compared among experimental combinations.
RESULTS Feline serum was more effective than canine or equine serum for minimizing corneal weight loss. Incubation with feline or equine, but not canine, serum significantly reduced hydroxyproline production. Serum storage duration did not affect corneal weight loss, but the hydroxyproline concentration was greater for corneal specimens that were incubated with serum that was stored for 90 days, compared with that for corneal specimens incubated with serum that was stored for 0, 30, or 180 days. Serum storage temperature did not affect corneal weight loss or hydroxyproline concentration.
CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that serum reduced corneal degradation in vitro, and the duration and temperature at which serum was stored did not affect its anticollagenase efficacy.
OBJECTIVE To compare the anticollagenase efficacy of fresh feline, canine, and equine serum and plasma on in vitro corneal degradation.
SAMPLE Grossly normal corneas from recently euthanized dogs, cats, and horses and fresh serum and plasma from healthy dogs, cats, and horses.
PROCEDURES Serum and plasma were pooled by species and used for in vitro experiments. Corneas were collected and stored at −80°C. Sections of cornea were dried, weighed, and incubated in saline (0.9% NaCl) solution with clostridial collagenase and homologous fresh serum or plasma. Corneal degradation was assessed as the percentage of corneal weight loss and hydroxyproline concentration, compared with results for positive and negative control samples.
RESULTS Homologous fresh serum and plasma significantly reduced the percentage of corneal weight loss, compared with results for positive control samples. No significant difference was found in percentage of corneal weight loss between incubation with serum or plasma for feline, canine, and equine corneas. Canine serum and plasma significantly reduced hydroxyproline concentrations, whereas inclusion of feline and equine serum or plasma did not, compared with results for positive control samples. Hydroxyproline concentrations were moderately correlated with percentage of corneal weight loss for feline samples and weakly correlated for equine samples, but they were not correlated for canine samples.
CONCLUSIONS AND CLINICAL RELEVANCE In this study, the anticollagenase efficacy of fresh feline, canine, and equine serum was not different from that of plasma. Plasma should be an acceptable substitute for serum in the topical treatment of keratomalacia.
Objective—To develop a reverse transcriptase-polymerase
chain reaction (RT-PCR) assay to detect feline
herpesvirus-1 (FHV-1) latency-associated transcripts
(LATs) in the corneas and trigeminal ganglia of cats
that did not have clinical signs of ocular disease.
Sample Population—Corneas and trigeminal ganglia
obtained from 21 cats necropsied at the Indiana
Animal Disease Diagnostic Laboratory and 25 cats
euthanatized at a humane shelter; none of the cats
had a recent history of respiratory tract or ocular disease,
and all had normal results for ophthalmic examinations.
Procedure—Both corneas and both trigeminal ganglia
were harvested from each cat. An initial PCR assay
detected FHV-1 DNA in the corneas and trigeminal
ganglia. The RNA was then isolated from samples
positive for FHV-1 DNA, and an RT-PCR assay was
used to detect LATs.
Results—FHV-1 DNA was detected in 45 of 92
(48.9%) corneas and 38 of 92 (41.3%) trigeminal ganglia.
In many samples, the RNA had degraded and RTPCR
assay was not possible. Of the samples subjected
to RT-PCR assay, none of the 39 corneas but 4 of
16 trigeminal ganglia had positive results when tested
Conclusions and Clinical Relevance—Analysis of
the results indicated that a high percentage of cats
that did not have clinical signs of ocular disease had
detectable FHV-1 DNA in their corneas and trigeminal
ganglia. This study documents that the RT-PCR assay
can successfully identify LATs and may serve as a
tool to better understand the biologic characteristics
of FHV-1 and its relationship to clinical disease. ( Am J Vet Res 2004;65:314–319)
Objective—To determine whether oral administration
of L-lysine to cats would lessen the severity of conjunctivitis
caused by feline herpesvirus (FHV-1).
Animals—8 healthy young adult cats.
Procedure—Cats received oral administration of
lysine monohydrochloride (500 mg, q 12 h) or placebo
(lactose) beginning 6 hours prior to inoculation of
virus. The left conjunctival sac received a 50-µl suspension
of FHV-1 grown in cell culture (1.8 X 108 tissue
culture infective dose50) on day 1. Cats were evaluated
and scores given for clinical signs each day for 21
days. Samples for virus isolation were collected from
the eye and throat every third day. Plasma lysine and
arginine concentrations were measured prior to the
study and on days 3, 14, and 22.
Results—Cats that received lysine had less severe
conjunctivitis than cats that received placebo. Virus
isolation results did not differ between the groups.
Plasma lysine concentration was significantly higher
in cats that received lysine, compared with control
cats, whereas plasma arginine concentrations did not
differ between groups.
Conclusion and Clinical Relevance—Oral administration
of 500 mg of lysine to cats was well tolerated
and resulted in less severe manifestations of conjunctivitis
caused by FHV-1, compared with cats that
received placebo. Oral administration of lysine may be
helpful in early treatment for FHV-1 infection by lessening
the severity of disease. (Am J Vet Res
OBJECTIVE To compare ultrasound biomicroscopy (UBM) with standard ocular ultrasonography for detection of canine uveal cysts and to determine the sensitivity, specificity, and interobserver agreement for detection of uveal cysts with UBM.
SAMPLE 202 enucleated eyes from 101 dogs.
PROCEDURES 2 examiners examined 202 eyes by means of UBM (50 MHz) to identify uveal cysts. A board-certified radiologist then examined 98 of the 202 eyes by means of standard ocular ultrasonography (7- to 12-MHz linear transducer). Subsequently, 1 examiner dissected all 202 eyes under magnification from an operating microscope to definitively identify uveal cysts. Each examiner was masked to other examiners’ findings. Sensitivity, specificity, and interobserver agreement were calculated for detection of cysts by UBM.
RESULTS Cysts were detected by use of UBM in 55 of 202 (27%) eyes by one examiner and 29 of 202 (14%) eyes by the other. No cysts were detected in the 98 eyes examined with standard ocular ultrasonography. Dissection results revealed that cysts were present in 64 of 202 (32%) eyes, including 29 of 98 (30%) eyes examined by standard ocular ultrasonography. Mean sensitivity of UBM for cyst detection was 47%; mean specificity was 92%. Uveal cysts not identified with UBM were often small (mean diameter, 490 üm). Interobserver agreement was high (κP = 0.81).
CONCLUSIONS AND CLINICAL RELEVANCE UBM was more effective than standard ocular ultrasonography for detection of uveal cysts in enucleated eyes. Small-diameter cysts were difficult to visualize even with UBM.