Charles S. Schobert

Superficial corneal squamous cell carcinoma occurring in dogs with chronic keratitis.

OBJECTIVE Canine corneal squamous cell carcinoma (SCC) is a rare tumor, with only eight cases previously published in the veterinary literature. The Comparative Ocular Pathology Lab of Wisconsin (COPLOW) has diagnosed 26 spontaneously occurring cases, 23 in the past 4 years. This retrospective study describes age and breed prevalence, concurrent therapy, biologic behavior, tumor size and character, and 6-month survival rates after diagnosis. RESULTS A search of the COPLOW database identified 26 corneal SCC cases diagnosed from 1978 to 2008. There is a strong breed predilection (77%) in brachycephalic breeds, particularly those prone to keratoconjunctivitis sicca. The mean age was 9.6 years (range 6-14.5 years). Follow-up information >6 months was available for 15 of 26 cases. Recurrence occurred in the same eye in nine cases, seven of which were incompletely excised at the time of first keratectomy. No cases were known to have tumor growth in the contralateral eye and no cases of distant metastases are known. Where drug history is known, 16 of 21 dogs had a history of treatment with topical immunosuppressive therapy (cyclosporine or tacrolimus) at the time of diagnosis. CONCLUSION Chronic inflammatory conditions of the cornea and topical immunosuppressive therapy may be risk factors for developing primary corneal SCC in dogs. SCC should be considered in any differential diagnosis of corneal proliferative lesions. Superficial keratectomy with complete excision is recommended, and the metastatic potential appears to be low.

Canine ocular gliomas: a retrospective study.

OBJECTIVE The purpose of this paper is to classify glial tumors observed in the canine retina and optic nerve, describe the histopathological features and provide prognostic information on these neoplasms. METHODS The database of the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW) was searched to collect canine glioma cases. Clinical and follow-up information was gathered from submission forms and an extensive follow-up survey. Slides were reviewed to describe the histopathological characteristics of the neoplasm and classify them. Immunohistochemistry for Glial Fibrillary Acidic Protein (GFAP) was performed in all cases. RESULTS 18 canine glioma cases were found in the COPLOW database. There was no breed or gender predilection. The mean age was 9.33 +/- 3.67 years. Follow-up information was available for 12 dogs, 8 of which were dead at the time of most recent contact, with a survival time ranging from 0 days (globes received after euthanasia) up to 20 months post-enucleation. In 6 of the 8 dogs that had died during this stud), tumor extended to the margin where the optic nerve had been sectioned. Light microscopic examination of the optic nerve of the affected eyes of four dogs that were still alive during this study revealed no tumor at this surgical margin. One neoplasm was classified as low-grade astrocytoma, 5 tumors as medium-grade astrocytoma, 11 tumors as high grade-astrocytoma and 1 tumor as oligodendroglioma. GFAP was positive in all but two tumors. CONCLUSION Retinal and optic nerve gliomas may be considered as differential diagnoses of intraocular and orbital masses. The metastatic potential appears to be low, but ascending invasion into the ventral aspect of the brain is possible.

Feline conjunctival melanoma: histopathological characteristics and clinical outcomes.

PURPOSE We report on the histopathology and clinical features of 21 cases of feline conjunctival melanoma. METHODS A total of 18 cases are from the COPLOW collection and three cases from Antech Diagnostics. We tabulated the location of the tumor, pigmentation, cell shape, mitotic index and presence of multinucleated tumor cells. Surveys were sent to referring ophthalmologists to obtain further information about each case. RESULTS The mean age of the cats was 12.4 years. A total of 11 cases were neutered males, six spayed females, and one each of intact female and male. Thirteen of the 21 cases were located on the bulbar conjunctiva, three on third eyelid only, three on palpebral conjunctiva. Sixteen tumors were pigmented while five were amelanotic. Seventeen of the cases consisted of round cell only while four cases were mixed populations of round and spindle cell. Fourteen of the cases contained multinucleated cells. The mitotic index ranged from 0 to 45 mitotic figures/10 HPF. Of the 13 cases with adequate follow-up information, four showed local recurrence while three reported metastasis. Eight cats had died at the time of the survey. Survival time post-diagnosis ranged from 0.5 to 36 months. Two cases had metastasized to the submandibular lymph nodes and in a third case, an abdominal mass was detected. CONCLUSIONS Feline conjunctival melanoma is most frequently found on the bulbar conjunctiva, are mostly round cells and suggest that conjunctival melanoma in cats has a poorer long term prognosis than the same neoplasm in dogs.

Do you see what I see? Optical morphology and visual capability of ‘disco’ clams (Ctenoides ales)

ABSTRACT The ‘disco’ clam Ctenoides ales (Finlay, 1927) is a marine bivalve that has a unique, vivid flashing display that is a result of light scattering by silica nanospheres and rapid mantle movement. The eyes of C. ales were examined to determine their visual capabilities and whether the clams can see the flashing of conspecifics. Similar to the congener C. scaber, C. ales exhibits an off-response (shadow reflex) and an on-response (light reflex). In field observations, a shadow caused a significant increase in flash rate from a mean of 3.9 Hz to 4.7 Hz (P=0.0016). In laboratory trials, a looming stimulus, which increased light intensity, caused a significant increase in flash rate from a median of 1.8 Hz to 2.2 Hz (P=0.0001). Morphological analysis of the eyes of C. ales revealed coarsely-packed photoreceptors lacking sophisticated structure, resulting in visual resolution that is likely too low to detect the flashing of conspecifics. As the eyes of C. ales are incapable of perceiving conspecific flashing, it is likely that their vision is instead used to detect predators. Summary: ‘Disco’ clams are known for their vivid flashing displays. Their vision was examined to see if their display is visible to other disco clams as a signal.