Objective—To evaluate the use of an intravitreal sustained-release cyclosporine (CsA) delivery device for treatment of horses with naturally occurring recurrent uveitis.
Animals—16 horses with recurrent uveitis.
Procedures—Horses with frequent recurrent
episodes of uveitis or with disease that was progressing
despite appropriate medication were selected
for this study. Additional inclusion criteria included
adequate retinal function as determined by use of
electroretinography, lack of severe cataract formation,
and no vision-threatening ocular complications (eg,
retinal detachment, severe retinal degeneration, and
posterior synechia). Sustained-release CsA delivery
devices (4 µg of CsA/d) were implanted into the vitreous
through a sclerotomy at the pars plana.
Reexaminations were performed 1, 3, 6, and 12
months after implantation, then continued annually.
Ophthalmic changes, number of recurrent episodes
of uveitis, and vision were recorded.
Results—The rate of recurrent episodes after device
implantation (0.36 episodes/y) was less than prior to
surgery (7.5 episodes/y). In addition, only 3 horses
developed episodes of recurrent uveitis after surgery.
Vision was detected in 14 of 16 affected eyes at a
mean follow-up time of 13.8 months (range, 6 to 24
Conclusions and Clinical Relevance—This intravitreal
sustained-release CsA delivery device may be a
safe and important tool for long-term treatment of
horses with chronic recurrent uveitis. (Am J Vet Res
Objective—To estimate intraocular pressure (IOP) in
eyes of healthy camelids, using applanation tonometry.
Animals—The eyes of 34 camelids (16 llamas [Lama
glama] and 18 alpacas [L pacos]) that did not have
major abnormalities of the ocular surface or intraocular
Procedure—Tonometry measurements were
obtained from each eye 3 times during a 24-hour period.
Each measurement was the mean of several
corneal applanations obtained by use of an applanation
tonometer. Data were analyzed, using an ANOVA
for a repeated-measures design.
Results—Mean (± SEM) IOP of llamas and alpacas
was 13.10 ± 0.35 and 14.85 ± 0.45 mm Hg, respectively.
Range of IOP was 7 to 18 mm Hg for llamas
and 11 to 21 mm Hg for alpacas. Mean IOP of llamas
was significantly less than the mean IOP of alpacas.
Significant differences in IOP were not detected
between the right and left eye of animals. Significant
differences in IOP were not attributed to sex, age, or
time of measurement within llamas or alpacas.
Conclusions and Clinical Relevance—Establishing
the mean and range of IOP of clinically normal llamas
and alpacas provides a frame of reference that is
important for use in a complete ophthalmic examination
of camelids, which can assist clinicians in the
diagnosis of glaucoma and uveitis. Reasons for the
difference in mean IOP between llamas and alpacas
are unknown. Although the difference may be unimportant
clinically, this finding reiterates the fact that
caution must be used when extrapolating IOP among
species. (Am J Vet Res 2000;61:1542–1544)
Objective—To evaluate the effect of topical administration
of 2% dorzolamide hydrochloride or 2% dorzolamide
hydrochloride-0.5% timolol maleate on intraocular
pressure (IOP) in clinically normal horses.
Animals—18 healthy adult horses without ocular
Procedure—The IOP was measured at 5 time points
(7 AM, 9 AM, 11 AM, 3 PM, 7 PM) over 11 days. On days
1 and 2, baseline values were established. On days 3
through 5, horses received 2% dorzolamide HCl
(group D, n = 9) or 2% dorzolamide HCl-0.5% timolol
maleate (group DT, 9) in 1 randomly assigned eye
every 24 hours immediately following each daily 7 AM
IOP measurement. On days 6 through 9, each drug
was given every 12 hours (7 AM and 7 PM) in the treated
eye. Measurements on days 10 and 11 assessed
return to baseline. Mixed linear regression models
compared mean IOP difference for each drug at each
Results—Mean IOP decreased significantly in all
eyes during the 2 dose/d period, compared with the
baseline, 1 dose/d, and follow-up periods.
Conclusions and Clinical Relevance—Administration
of either drug every 24 hours for short-term
treatment does not reduce IOP significantly.
Administering either drug every 12 hours induced a
significant reduction of IOP; however, controlling for
all variables, the reduction was less than 2 mm Hg.
(Am J Vet Res 2001;61:709–713)
Objective—To determine effects of topical antimicrobial
and antimicrobial-corticosteroid preparations on
the ocular flora of horses.
Procedure—One eye was treated 3 times daily for 2
weeks with one of the following ointments: 1) neomycinbacitracin-
polymyxin B, 2) 0.6% prednisolone-0.3% gentamicin,
3) neomycin-polymyxin B-0.05% dexamethasone,
or 4) treated (artificial tears) control. Contralateral eyes of
treated control eyes served as untreated control eyes.
Corneal and conjunctival specimens for bacterial and fungal
cultures were collected prior to initiation of treatment,
after 1 and 2 weeks of treatment, and 2 weeks after concluding
treatment. Changes in culture growth quantity
scores of bacterial and fungal species were analyzed.
Results—The most common species before treatment
were the following: gram-positive bacteria included
Streptomyces spp (66%) , Staphylococcus spp (46%) ,
Bacillus spp (32%) , and Streptococcus spp (32%); gramnegative
bacteria included Moraxella spp (28%) ,
Escherichia coli (24%) , Acinetobacter spp (18%), and
Enterobacter spp (14%); and fungi included Aspergillus
nidulans (56%) , Cladosporium spp (32%), and
Aspergillus fumigatus (22%). In all groups, the percentage
of positive bacterial culture results, growth quantity
score of gram-positive bacteria, and number of bacterial
species isolated decreased at week 1 and increased at
week 2, whereas growth quantity score of gram-negative
bacteria decreased throughout treatment. Differences
were not significant among groups. Fungal growth quantity
score decreased during treatment in all groups.
Repopulation of bacterial and fungal species occurred.
Conclusions and Clinical Relevance—All interventions
decreased the number of microorganisms.
Repopulation of normal flora occurred during and after
treatment. (Am J Vet Res 2005;66:800–811)
Objective—To compare the iridocorneal angle (ICA) and angle opening distance (AOD) in dogs with cataractous and noncataractous lenses; evaluate cataractous eyes ultrasono-graphically for association of postoperative ocular hypertension (POH) with the ICA, AOD, and postoperative echogenic anterior chamber debris; and evaluate intraobserver reliability associated with ICA and AOD measurements.
Animals—56 dogs with 102 cataracts, and 23 clinically normal dogs.
Procedures—Ultrasound biomicroscopy was performed on 102 eyes of 56 dogs before and after cataract surgery and on 46 nondilated and dilated eyes of 23 clinically normal dogs. Cataract stage, ICA, AOD, and association with POH were assessed.
Results—Cataract stage and ICA or AOD were not significantly associated; however, ICA and AOD typically decreased with increasing cataract maturity. Before and after pupillary dilation, AODs were significantly smaller in cataractous eyes than in noncataractous eyes. Before surgery, ICA and AOD in eyes without pupillary dilation were significantly associated with POH. At > 13°, odds of developing POH increased by 11% for each degree increase in the ICA. Postoperative anterior chamber debris was not associated with POH. Coefficient of variation for repeated measurements was 10% for the ICA and 9.5% for the AOD, suggesting good intraobserver reliability.
Conclusions and Clinical Relevance—In this study, dogs with larger ICA and AOD measurements before surgery were at greater risk of developing POH. This information may be useful for future studies to determine whether preventative treatment for POH administered prior to surgery may be beneficial.
OBJECTIVE To determine the effects of grape seed extract (GSE), lutein, and fish oil containing omega-3 fatty acids on oxidative stress, migration, proliferation, and viability of lens epithelial cells (LECs).
SAMPLE Lens capsules or cultured LECs obtained from canine cadavers.
PROCEDURES An antioxidant reductive capacity assay was used to determine reducing capability of each substance. The LECs were cultured and incubated with various substances, including N-acetyl cysteine (NAC), when appropriate, and dimethyl sulfoxide (DMSO) as positive and vehicle control substances, respectively. A dichlorofluorescein assay was used to evaluate reactive oxygen species (ROS) production, and a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to determine cell viability. Ex vivo posterior capsule opacification (PCO) was used to evaluate LEC migration and proliferation.
RESULTS Antioxidant reductive effects of GSE surpassed those of NAC, lutein, and fish oil containing omega-3 fatty acids. The GSE reduced ROS production in LECs, compared with the DMSO vehicle control, whereas lutein was pro-oxidative. All test substances reduced cell viability. Ex vivo PCO was not altered by GSE, was decreased by lutein, and was increased by fish oil containing omega-3 fatty acids, compared with results for the DMSO vehicle control.
CONCLUSIONS AND CLINICAL RELEVANCE Only GSE had significant antioxidant capabilities and reduced ROS production; however, no effect on ex vivo PCO was detected. Fish oil containing omega-3 fatty acids increased ex vivo PCO. No conclusions could be made regarding antioxidant effects of these substances on LECs. These findings suggested that the substances will not decrease PCO.