Ocular and neural distribution of feline herpesvirus-1 during active and latent experimental infection in cats.

BACKGROUND: Herpes simplex virus 1 (HSV-1) and varicella zoster virus (VZV) cause extensive intra-ocular and neural infections in humans and are closely related to Felid herpes virus 1 (FeHV-1). We report the extent of intra-ocular replication and the extent and morphological aspects of neural replication during the acute and latent phases of FeHV-1 infection. Juvenile, SPF cats were inoculated with FeHV-1. Additional cats were used as negative controls. Cats were euthanized on days 6, 10, and 30 post-inoculation. RESULTS: FeHV-1 was isolated from the conjunctiva, cornea, uveal tract, retina, optic nerve, ciliary ganglion (CG), pterygopalatine ganglion (PTPG), trigeminal ganglion (TG), brainstem, visual cortex, cerebellum, and olfactory bulb of infected cats during the acute phase, but not the cranial cervical ganglion (CCG) and optic chiasm. Viral DNA was detected in all tissues during acute infection by a real-time quantitative PCR assay. On day 30, viral DNA was detected in all TG, all CCG, and 2 PTPG. Histologically mild inflammation and ganglion cell loss were noted within the TG during acute, but not latent infection. Using linear regression, a strong correlation existed between clinical score and day 30 viral DNA copy number within the TG. CONCLUSIONS: The correlation between clinical score and day 30 viral DNA copy number suggests the severity of the acute clinical infection is related to the quantity of latent viral DNA. The histologic response was similar to that seen during HSV-1 or VZV infection. To the author's knowledge this is the first report of FeHV-1 infection involving intraocular structures and autonomic ganglia.

Proliferation of Streptococcus zooepidemicus and Pseudomonas aeruginosa within a simulated subpalpebral lavage flushed with equine serum.

OBJECTIVE: To evaluate whether equine serum administered via a simulated subpalpebral lavage system (SPL) supports proliferation of Streptococcus zooepidemicus or Pseudomonas aeruginosa within the tubing. PROCEDURES: A sterile i.v. catheter with injection cap was inserted into sterilized silicone tubing (Mila). To mimic an SPL within the dorsal conjunctival fornix, the tubing was secured to an elevated platform. The tip of the tubing extended from the platform into a vial containing culture medium just inoculated with approximately 1.5 x 10(8) CFU/mL P. aeruginosa or S. zooepidemicus. To mimic administration of medication, the tubing was infused twice daily with equine serum, sterile saline (negative control), or culture medium (positive control) followed by air. Incubation was at 25 or 37 degrees C. At 24, 48, and 72 h postinoculation, samples were obtained for bacterial culture from one simulated SPL for each experimental variant. The following sections were cultured: (i) tubing tip previously submerged in the inoculated culture medium, (ii) tubing mid-section, and (iii) tip of the i.v. catheter. The experiment was performed in triplicate. RESULTS: Streptococcus zooepidemicus or P. aeruginosa were isolated from 100% of the tubing tips. Streptococcus zooepidemicus was isolated from one mid-section flushed with culture medium incubated at 37 degrees C. All other samples were negative for growth of the inoculated agents. CONCLUSIONS: Streptococcus zooepidemicus and P. aeruginosa did not proliferate within silicone tubing infused with equine serum. These data suggest that topical serum can be safely administered through a superiorly placed SPL in clinical cases.

Feline primary open angle glaucoma.

OBJECTIVES: We have documented the histomorphological features of feline primary open angle glaucoma. DESIGN: A retrospective morphologic study of eight affected eyes from eight cats, from 1992 to 2006 extracted from a pathology collection, which includes 4000 feline submissions and 1100 cases of feline glaucoma. PROCEDURE: Sections of affected globes, stained with H&E or with alcian blue were examined with a light microscope. Eyes that did not fulfill the criteria for primary open angle glaucoma were excluded from the study. RESULTS: The mean age was 9.1 years. Five cats were female and three cats were male. The breeds included five DSH, two Burmese, and one DLH cat. Significant histomorphological findings included an open irido-corneal angle with an open ciliary cleft in all cases, loss of ganglion cells in eight of eight cases, cupping and gliosis of the optic nerve head in four of four cases in which the optic nerve was adequately sampled, and myxomatous changes of the stroma surrounding the vortex veins in seven of eight cases. CONCLUSIONS: Primary open angle glaucoma in cats is a rare disease that should be taken into consideration when investigating cases of feline glaucoma. The pathogenesis of aqueous outflow obstruction in these cases is not known. This study describes eight additional cases of feline primary open angle glaucoma in cats without an identified cause.

Feline early life ocular disease.

OBJECTIVES: Histomorphologic changes in six globes from six cats, which experienced early life ocular disease of undetermined etiology, are described. DESIGN: A retrospective morphologic study of six eyes from six cats with early life ocular surface disease of unknown etiology, from 2002 to 2006 extracted from a pathology collection, which includes 2200 feline submissions. PROCEDURE: Sections of affected globes, stained with H&E were examined with a light microscope. RESULTS: The mean age of the affected cats, at the time of enucleation, was 7.5 months ranging from 7 weeks to 2 years. The cats were one male, one female, one male neutered, and one female spayed cat. For the remaining two cats the sex was not known. All cats were DSH. Significant histomorphologic findings included collapse of the globe in all cases and a broad corneal perforation with protrusion of the anterior uvea, which was epithelialized in all cases. Three cases revealed uveal hematopoiesis in the anterior and posterior uvea. All cases had recognizable corneal tissue at the limbus on both sides. Inflammation in all cases consisted of variable but generally mild uveitis and no eyes had endophthalmitis. Four of the globes had no recognizable lens tissue. Three of the cats had symblepharon formation described as part of the clinical condition. The other three cases had no mention of symblepharon. CONCLUSIONS: These cases are considered to represent changes associated with early life corneal ablation of unknown etiology. Uveal prolapse, mild inflammation, and symblepharon are considered to be either secondary or caused by the same destructive primary event that affected the cornea. These cases are the first cases we are aware of with uveal extramedullary hematopoiesis in cats. Careful consideration of cell morphology is necessary to distinguish this condition from round cell neoplasms or inflammation.

Use of an axial pattern flap and nictitans to reconstruct medial eyelids and canthus in a dog.

A 10-year-old male neutered Boxer presented with recurrence of a mast cell tumor at the right medial canthal area. Following excision including 2 cm margins, the medial one-half of the upper and lower eyelids and the medial canthus were reconstructed using an axial pattern flap based on the cutaneous branch of the superficial temporal artery. The bulbar conjunctiva of the nictitans was preserved and sutured to the medial flap edge, thus creating a conjunctival lining to the deep aspect of the flap, protecting corneal epithelium. This is a valuable surgical technique for closing a large skin defect and reconstructing the medial eyelids, thus preserving the globe.

Intraocular lens with reversibly adjustable optical power: pilot study of concept and safety.

PURPOSE: To evaluate whether it is technically feasible and safe to implant and adjust an intraocular lens (IOL) with reversibly adjustable refractive power designed to correct residual postoperative refractive error. SETTING: Animal study facility, Klinikum Mannheim, University of Heidelberg, Heidelberg, Germany. METHODS: An Acri.Tec AR-1 posterior chamber IOL (PC IOL) was implanted in pig cadaver eyes and in rabbit eyes after the crystalline lens was removed by phacoemulsification. The IOL was manipulated to change the refractive power. The outcome measures were the stability of the IOL during implantation, IOL positioning and rotation, the ability to move the adjustment device after the IOL had been implanted for several weeks, clinical signs of inflammation, and changes in the histopathologic appearance of the eye. RESULTS: Implantation and adjustment of refractive power were possible. The eyes healed normally. There was no difference between eyes with the AR-1 PC IOL and eyes with a control IOL in inflammatory reaction, corneal transparency, or histopathologic appearance. CONCLUSION: The AR-1 PC IOL was easy to implant and well tolerated in rabbit eyes. Surgical adjustment of the adjusting element was performed with little effort several weeks after implantation of the IOL.