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 evaluate the outcome of thermokeratoplasty
for treatment of ulcerative keratitis and bullous
keratopathy secondary to corneal endothelial disease
Procedures—Medical records from 1994 to 2001 for
dogs evaluated because of ulcerative keratitis and
bullous keratopathy and treated with thermokeratoplasty
Results—There were 7 spayed females, 5 castrated
males, and 1 sexually intact male, ranging from 6 to
16 years of age. Ten dogs had endothelial degeneration,
and 3 dogs had breed-related endothelial dystrophy.
All dogs had bullous keratopathy, characterized
by microbullae formation that was detected via biomicroscopy.
Recurrent or nonhealing corneal ulcers
were detected unilaterally in 5 dogs and bilaterally in
8 dogs. Mean ± SD duration from thermokeratoplasty
until ulcerations were healed for all dogs was 2.2 ±
1.1 weeks. All dogs that underwent thermokeratoplasty
for nonhealing corneal ulceration secondary to
endothelial disease and corneal edema had epithelial
wound healing and resolution of corneal ulceration.
Mean duration of treatment (ie, topical treatment
required until resolution of ulceration) was significantly
less after thermokeratoplasty than duration of
treatment (with multiple treatments) prior to referral.
Conclusions and Clinical Relevance—It may be
necessary to perform thermokeratoplasty of the
entire cornea to prevent recurrence of ulcerations
in areas that have not been treated with thermokeratoplasty.
(J Am Vet Med Assoc 2003;222:
Objective—To determine histologic and immunohistochemical
characteristics of the multifocal adherent
plaques that commonly develop on the internal surfaces
of the anterior and posterior lens capsules in
dogs with cataracts.
Sample Population—31 anterior and 4 posterior capsular
specimens collected during lens extraction
surgery in dogs with cataracts.
Procedure—Specimens were evaluated, using light
and transmission electron microscopy. Immunohistochemical
techniques were used to localize cytokeratin,
vimentin, α-smooth muscle-specific actin,
fibronectin, tenascin, and transforming growth factor-
β (TGF-β) within plaques.
Results—Histologically, plaques comprised elongated
spindle-shaped cells that formed a placoid mass. Cells
were embedded in an extracellular matrix containing
collagen fibrils, often with duplicated or split basement
membranes. Immunohistochemically, normal lens
epithelial cells and cells within plaques stained for
vimentin. Most cells and some areas of the extracellular
matrix within plaques stained for TGF-β and
α-smooth muscle-specific actin. Fibronectin and
tenascin were also detected in the extracellular matrix.
Conclusions and Clinical Relevance—Canine lens
capsular plaques are histologically and immunohistochemically
similar to posterior capsule opacification
and subcapsular cataracts in humans, which suggests
that the canine condition, like the human conditions,
is associated with fibrous metaplasia of lens epithelial
cells. Transforming growth factor-β may play a role in
the genesis of capsular plaques. Because severity of
plaques was correlated with stage of cataract development,
earlier surgical removal of cataracts may be
useful to avoid complications associated with plaque
formation. (Am J Vet Res 2000;61:139–143)
Objective—To determine appropriate intraocular lens (IOL) implant strength to approximate emmetropia in horses.
Sample Population—16 enucleated globes and 4 adult horses.
Procedures—Lens diameter of 10 enucleated globes was measured. Results were used to determine the appropriate-sized IOL implant for insertion in 6 enucleated globes and 4 eyes of adult horses. Streak retinoscopy and ocular ultrasonography were performed before and after insertion of 30-diopter (D) IOL implants (enucleated globes) and insertion of 25-D IOL implants (adult horses).
Results—In enucleated globes, mean ± SD lens diameter was 20.14 ± 0.75 mm. Preoperative and postoperative refractive state of enucleated globes with 30-D IOL implants was −0.46 ± 1.03 D and −2.47 ± 1.03 D, respectively; preoperative and postoperative difference in refraction was 2.96 ± 0.84 D. Preoperative anterior chamber (AC) depth, crystalline lens thickness (CLT), and axial globe length (AxL) were 712 ± 0.82 mm, 11.32 ± 0.81 mm, and 40.52 ± 1.26 mm, respectively; postoperative AC depth was 10.76 ± 1.16 mm. Mean ratio of preoperative to postoperative AC depth was 0.68. In eyes receiving 25-D IOL implants, preoperative and postoperative mean refractive error was 0.08 ± 0.68 D and −3.94 ± 1.88 D, respectively. Preoperative AC depth, CLT, and AxL were 6.36 ± 0.22 mm, 10.92 ± 1.92 mm, and 38.64 ± 2.59 mm, respectively. Postoperative AC depth was 8.99 ± 1.68 mm. Mean ratio of preoperative to postoperative AC depth was 0.73.
Conclusions and Clinical Relevance—Insertion of 30-D (enucleated globes) and 25-D IOL implants (adult horses) resulted in overcorrection of refractive error.
Objective—To characterize clinical and clinicopathologic
findings, response to treatment, and causes of
systemic hypertension in cats with hypertensive
Animals—69 cats with hypertensive retinopathy.
Procedure—Medical records from cats with systemic
hypertension and hypertensive retinopathy were
Results—Most cats (68.1%) were referred because
of vision loss; retinal detachment, hemorrhage,
edema, and degeneration were common findings.
Cardiac abnormalities were detected in 37 cats, and
neurologic signs were detected in 20 cats.
Hypertension was diagnosed concurrently with chronic
renal failure (n = 22), hyperthyroidism (5), diabetes
mellitus (2), and hyperaldosteronism (1). A clearly
identifiable cause for hypertension was not detected
in 38 cats; 26 of these cats had mild azotemia, and 12
did not have renal abnormalities. Amlodipine
decreased blood pressure in 31 of 32 cats and
improved ocular signs in 18 of 26 cats.
Conclusions and Clinical Relevance—Retinal
lesions, caused predominantly by choroidal injury, are
common in cats with hypertension. Primary hypertension
in cats may be more common than currently
recognized. Hypertension should be considered in
older cats with acute onset of blindness; retinal
edema, hemorrhage, or detachment; cardiac disease;
or neurologic abnormalities. Cats with hypertensioninduced
ocular disease should be evaluated for renal
failure, hyperthyroidism, diabetes mellitus, and cardiac
abnormalities. Blood pressure measurements
and funduscopic evaluations should be performed
routinely in cats at risk for hypertension (preexisting
renal disease, hyperthyroidism, and age > 10 years).
Amlodipine is an effective antihypertensive agent in
cats.(J Am Vet Med Assoc 2000;217:695–702)