A comparison of retrobulbar and two peribulbar regional anesthetic techniques in dog cadavers

Objective

To compare injectate distribution and likelihood of regional anesthesia to the orbit following retrobulbar (RB) or peribulbar (PB) injections in dog cadavers.

Chitosan and Hyaluronic Acid Nanoparticles as Vehicles of Epoetin Beta for Subconjunctival Ocular Delivery

Neuroprotection in glaucoma using epoetin beta (EPOβ) has yielded promising results. Our team has developed chitosan-hyaluronic acid nanoparticles (CS/HA) designed to carry EPOβ into the ocular globe, improving the drug’s mucoadhesion and retention time on the ocular surface to increase its bioavailability. In the present in vivo study, we explored the possibility of delivering EPOβ to the eye through subconjunctival administration of chitosan-hyaluronic acid-EPOβ (CS/HA-EPOβ) nanoparticles. Healthy Wistar Hannover rats (n = 21) were split into 7 groups and underwent complete ophthalmological examinations, including electroretinography and microhematocrit evaluations before and after the subconjunctival administrations. CS/HA-EPOβ nanoparticles were administered to the right eye (OD), and the contralateral eye (OS) served as control. At selected timepoints, animals from each group (n = 3) were euthanized, and both eyes were enucleated for histological evaluation (immunofluorescence and HE). No adverse ocular signs, no changes in the microhematocrits (≈45%), and no deviations in the electroretinographies in both photopic and scotopic exams were observed after the administrations (p < 0.05). Intraocular pressure remained in the physiological range during the assays (11–22 mmHg). EPOβ was detected in the retina by immunofluorescence 12 h after the subconjunctival administration and remained detectable until day 21. We concluded that CS/HA nanoparticles could efficiently deliver EPOβ into the retina, and this alternative was considered biologically safe. This nanoformulation could be a promising tool for treating retinopathies, namely optic nerve degeneration associated with glaucoma.     

兽医眼表移植学及植片材料的研究进展

角膜疾病是动物最常见的眼科疾病之一,治疗不当将引起视力减退、致盲甚至眼球摘除,给动物带来巨大的痛苦与生活障碍.兽医眼表移植手术经历了多年的研究探索与改良,成为治疗动物角膜损伤、挽救眼球甚至恢复视力的有效方法.不同的手术方式与移植材料对于角膜愈合、免疫排斥、光学性以及眼球形态产生深远的意义和影响.现就各种眼表移植技术以及...     

'D-shaped' and 'reverse-D-shaped' pupil in a cat with lymphosarcoma

A 7-year-old female spayed European shorthair cat was presented because of visual reduction and a green reflex in the right eye. Examination revealed a 'D-shaped' pupil in the right eye and a 'reverse-D-shaped' pupil in the left eye. Both eyes showed fibrinous anterior uveitis with exudates in the anterior chamber and precipitates on the posterior surface of the cornea. In both eyes a chorioretinitis was diagnosed which caused partial retinal detachment and peripapillary oedema in the left eye. Histopathology revealed intestinal and ocular lymphosarcoma. The aberrant pupil shapes which persisted after death were due to infiltration of the iris stroma and were not caused neurologically. The observation that in both eyes only the medial parts of the iris were affected could not be explained.     

ULTRASONOGRAPHIC DIAGNOSIS OF PERSISTENT HYPERPLASTIC TUNICA VASCULOSA LENTIS/PERSISTENT HYPERPLASTIC PRIMARY VITREOUS IN TWO DOGS

Ultrasonography was performed on a Basset hound and a Doberman clinically suspected of persistent hyperplastic tunica vasculosa lentis/persistent hyperplastic primary vitreous. In both dogs, hyperechoic lenses with a triangular-shaped echodense structure retrolentally were visible, and a very thin hyperechoic strand was seen penetrating the anechoic vitreous from this retrolental tissue to the area of the optic nerve. Using color Doppler imaging, blood flow was evident in parts of the retina in both dogs. With power Doppler imaging there was blood flow in the lens and hyperechoic strand of the Basset hound on the first examination; whereas, on re-examination 5 months later, this was not found. Other abnormalities, such as retinal detachment, endophthalmitis, vitreous hemorrhage, microphthalmia, and posterior neoplasia could be excluded.     

Amniotic membrane transplantation for the reconstruction of the ocular surface in three cases

This paper describes the use of amniotic membrane in the reconstructive surgical repair of generalized keratomalacia, ankyloblepharon, and after fibrous histiocytoma removal in two dogs and a cat. Case 1 was an 11-year-old female Yorkshire terrier with severe bullous keratomalacia in the left eye (OS). A frozen canine amniotic membrane graft and a third eyelid flap were applied. At day 80 postoperatively, only a mild scar and corneal vascularization were present. Case 2 was a 4-year-old female Siamese cat with symblepharon of both eyes after rhinotracheitis. Resection of the conjunctiva and frozen canine amniotic membrane transplant were performed. One month later, there was a little corneal scarring and corneal vascularization. Case 3 was a 6-year-old female terrier with a scleral and corneal mass at the 11-12 o'clock position (OS). Resection of the mass and amniotic membrane transplantation were performed. The mass was a fibrous histiocytoma localized to the sclera and cornea. This eye healed with mild conjunctivalization and no pigmentation. Amniotic membrane transplantation can be used as a method of reconstruction of the ocular surface with good repair of the cornea and minimal scarring in small animals.     

Feline chlamydiosis

Chlamydiae are an important cause of acute and chronic conjunctivitis in cats. Until recently, only one organism was thought to infect cats, Chlamydophila felis (previously Chlamydia psittaci var. felis). Recently, other Chlamydia-like organisms belonging to the family Parachlamydiaceae, which comprises organisms that reside and proliferate within free-living amoeba, have been identified in cats with neutrophilic and eosinophilic conjunctivitis. The relative importance of these organisms and their amoebic hosts requires investigation. There is also weak evidence that chlamydiae may also be capable of causing reproductive tract disease and lameness in cats. Diagnosis of chlamydial conjunctivitis requires use of specialized culture techniques or the polymerase chain reaction. The antibiotic of choice to treat these infections is doxycycline; azithromycin is less effective. All cats in the household should be treated simultaneously. The zoonotic potential of these organisms appears low, but some precaution is warranted when handling affected cats.     

Keratitis due to microfilariae in dogs: a newly recognized disease

Parasitic agents have been associated with keratitis, but a diagnosis of parasitic keratitis has not been commonly made in domestic animals. The purpose of this study was to describe the clinical and histopathological findings in seven dogs with chronic keratitis caused by microfilariae diagnosed in Brazil. All dogs presented with superficial corneal opacities of varying degrees affecting the perilimbal and central regions of the cornea, with other opaque areas appearing as crystalline deposits and corneal vascularization. The lesions were bilateral and were associated with mild‐to‐moderate conjunctival hyperemia. There was no history of blepharospasm or pruritus, and no subjects presented with epithelial erosions. Corneal biopsy revealed free microfilariae in the corneal stroma, with varying degrees of inflammation and collagen fiber destruction. The microfilariae were also found in skin lesions by skin snip technique. No adult worms were found in these dogs, and no dogs were on heartworm preventative before diagnosis. Monthly doses of oral ivermectin improved ocular and dermal lesions. One dog showed complete remission with the treatment. The species of the microfilariae was not identified.