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 determine whether a chemokine
(RANTES)-like protein expressed by ciliary epithelium
plays a role in uveitis.
Sample Population—3 clinically normal horses intradermal,
5 eyes from 5 horses with recurrent uveitis,
and 10 normal eyes from 5 age- and sex-matched
Procedure—Cross-reactivity and sensitivity of recombinant
human (rh)-regulated upon activation, normal
T-cell expressed and secreted (RANTES) protein were
evaluated in horses by use of intradermal hypersensitivity
reactions and a chemotaxis assay. Aqueous
humor and ciliary body of eyes from clinically normal
horses and horses with uveitis were examined for
RANTES expression by use of an ELISA and reverse
transcription-polymerase chain reaction (RT-PCR).
Expression of RANTES mRNA and protein content of
primary cultures of equine ciliary pigmented epithelial
cells (RT-PCR) and culture supernatant (ELISA) were
measured 6 or 24 hours, respectively, after cultures
were stimulated with interleukin-1β and tumor necrosis
Results—Strong reactions to intradermal hypersensitivity
testing and significant chemotaxis of equine
leukocytes to rh-RANTES wereas observed. Aqueous
humor of eyes from horses with uveitis contained
increased concentrations of rh-RANTES-like protein
(mean ± SD, 45.9 ± 31.7 pg/ml), compared with aqueous
humor from clinically normal horses (0 pg/ml).
Ciliary body from horses with uveitis expressed
RANTES mRNA, whereas ciliary body from clinically
normal horses had low mRNA expression. Stimulated
ciliary pigmented epithelial cells expressed increased
amounts of rh-RANTES-like protein (506.1 ± 298.3
pg/ml) and mRNA, compared with unstimulated samples.
Conclusions and Clinical Relevance—Ciliary epithelium
may play a role in recruitment and activation of
leukocytes through expression of RANTES.
(Am J Vet Res 2002;63:942–947)