Objective—To compare in vitro and in vivo absorptive
capacities of modified Schirmer tear test strips with
those of original strips, and to establish reference values
for use with the modified strips.
Procedure—In vitro absorptive capacity was determined
by immersing strips in an irrigating solution for
15 seconds and recording amount of wetting. In vivo
absorptive capacity was determined by placing an original
Schirmer tear test strip in 1 eye and a modified
strip in the other eye of 50 dogs with normal or abnormal
tear production. Time required to wet 10 mm of
each strip was recorded. Measurements were repeated
30 minutes later after reversing which strip was
placed in the left or right eye. Reference values (mean
± SD) were determined by recording the time required
to wet 10 mm of the modified strip in 50 healthy dogs.
Results—Amount of wetting was significantly less
and time required to wet 10 mm was significantly
greater for the modified strip, compared with the original
strip. Reference values determined for the modified
strip were 32 ± 11 seconds in the right eye, 33 ±
11 seconds in the left eye, and 32 ± 10 seconds in
Conclusion and Clinical Relevance—Absorptive
capacities of the original and modified Schirmer tear
test strips were significantly different. Reference values
determined for 1 strip should not be used for the
other strip. (J Am Vet Assoc 2000;216:1576–1577)
Objective—To compare mean healing times after
debridement, debridement with grid keratotomy, and
superficial keratectomy in cats with nonhealing
Animals—29 cats with 36 nonhealing corneal ulcers.
Procedure—Medical records of cats with nonhealing
corneal ulcers were reviewed. Signalment, duration
of clinical signs, ophthalmic abnormalities, and
response to various treatment protocols were
Results—Mean age of affected cats was 7 years, 8
months. Affected breeds included domestic shorthair
(17 cats), Persian (9), Himalayan (2), and Siamese (1).
Clinical signs were evident for approximately 2 weeks
prior to referral. Both eyes were affected in 4 cats.
Mean healing time of ulcers treated with superficial
debridement was 30 days. Mean healing time of
ulcers treated with superficial debridement and grid
keratotomy was 42 days. Superficial keratectomy was
performed on 2 eyes and resulted in a healing time of
2 weeks. Formation of a corneal sequestrum was evident
in 2 of 21 eyes treated with superficial debridement.
Formation of a corneal sequestrum was evident
in 4 of 13 eyes treated with superficial debridement
and grid keratotomy.
Conclusions and Clinical Relevance—Brachycephalic
cats appear to be predisposed to developing
nonhealing corneal ulcers. The combination of superficial
debridement and grid keratotomy did not
decrease mean healing time of nonhealing ulcers,
compared with superficial debridement alone. Grid
keratotomy may predispose cats with corneal ulcers
to develop a corneal sequestrum. (J Am Vet Med
Objective—To characterize the clinical and morphologic
aspects of aqueous humor misdirection syndrome
(AHMS) in cats and provide a hypothesis
regarding its pathogenesis on the basis of detailed
analysis of affected cats.
Animals—32 cats (40 eyes).
Procedure—Medical records of cats in which AHMS
was diagnosed from July 1997 to August 2003 were
reviewed. In certain cats, results of additional diagnostic
testing were also obtained, including A-scan,
B-scan, and high-resolution ultrasonography; streak
retinoscopy; video keratometry; and infrared neutralizing
videoretinoscopy as well as results of analysis of
flash-frozen sections and histologic examination of
Results—Cats had a uniformly shallow anterior
chamber, intact lens zonules, and a narrowed
approach to an open iridocorneal angle. Mean age of
affected cats was 11.7 years (range, 4 to 16 years),
and female cats were significantly more often affected
than male cats. Clinical signs included mydriasis,
decreased pupillary light reflex, decreased menace
response, and blindness. Glaucomatous changes to
the optic nerve, incipient cataracts, and eventual
blindness were seen. Intraocular pressure was ≥ 20
mm Hg (range, 12 to 58 mm Hg) in 32 of 40 eyes.
Ultrasonography and histologic examination revealed
a thickened anterior vitreal face interposed between
the lens and ciliary body, partial ciliary cleft collapse,
and cavitated vitreal regions. Various treatment
modalities were used.
Conclusions and Clinical Relevance—AHMS affects
older cats, especially females, and may result in glaucoma,
vision loss, and signs of ocular pain. Topical
administration of carbonic anhydrase inhibitors
decreased intraocular pressure. (J Am Vet Med Assoc
To identify genetic associations with primary glaucoma (PG) in American Cocker Spaniels using a genome-wide association study (GWAS).
A nationwide ambidirectional case–control cohort study was performed in American Cocker Spaniels that had an ophthalmic examination performed by a veterinarian. Ninety-four dogs with PG (cases) and 111 dogs without glaucoma (controls) met phenotypic criteria and had a blood sample collected after receiving informed owner consent.
Genomic DNA was extracted from whole blood samples and genotyped (CanineHD BeadChip, Illumina Inc). A case–control GWAS using a linear mixed model was performed, and 3 significance thresholds were calculated (1) using a Bonferroni correction on all single nucleotide polymorphisms (SNPs) included in the GWAS, (2) using a Bonferroni correction on only the unlinked SNPs from a pruned data set, and (3) using 10,000 random phenotype permutations.
Following genotype data quality control, 89 cases and 93 controls were included in the GWAS. We identified an association on canine chromosome (CFA10); however, it did not reach statistical significance. Potential candidate genes within the surrounding linkage disequilibrium interval include coiled-coil domain containing 85A (CCDC85A) and extracellular growth factor containing fibulin extracellular matrix protein 1 (EFEMP1).
Primary glaucoma in the American Cocker Spaniel is a complex heterogeneous disease that may be influenced by a locus on CFA10. The candidate genes CCDC85A and EFEMP1 within the identified linkage disequilibrium interval have been shown to be involved in human open-angle glaucoma.