ABSTRACT
Retinal ischemia is a common cause of visual impairment for humans and animals. The neuroprotective effects of lidocaine (LDC) and methylprednisolone (MP) upon retinal ischemic injury were investigated in a rat model. Sprague-Dawley rats were divided into 3 groups, the IR control, LDC and MP. A very high intraocular pressure (HIOP) and retinal ischemia were induced. In LDC group, LDC bolus (1.5 mg/kg) was i.v. injected 30 min before ischemia and then a constant rate infusion (CRI) with 2 mg/kg/hr was given until 60 min after reperfusion. In MP group, MP bolus (30 mg/kg) was i.v. administered twice at 2 min before and immediately after ischemia, respectively. The HIOP damage to retina was evaluated by electroretinogram (ERG) and morphometrical histology. The functional analysis of the retina by ERG revealed a 35.2% reduction of a-wave in the IR group, 49.7% reduction in the LDC group but no significant change in the MP group compared to normal controls. An 81.0% reduction of b-wave was observed in the IR group, 80.7% reduction in the LDC group and 17.6% reduction in the MP group. In the morphometrical histology, the retinal inner plexiform layer/outer nuclear layer (IPL/ONL) ratio was reduced to 48.8% in the IR group, 80.1% in the LDC group and 96.2% in MP group. In conclusion, the MP showed significantly good neuroprotective effects on retinal IR injury, and the LDC showed moderate neuroprotective effects demonstrated in retinal structure but not in retinal function.
Subject(s)
Lidocaine/pharmacology , Methylprednisolone/pharmacology , Neuroprotective Agents/pharmacology , Reperfusion Injury/drug therapy , Retinal Diseases/prevention & control , Anesthetics, Local/pharmacology , Animals , Anti-Inflammatory Agents/pharmacology , Blindness , Electroretinography , Intraocular Pressure , Male , Rats , Rats, Sprague-Dawley , Retinal Diseases/etiologyABSTRACT
Maxillary bone epithelial cyst is rare in dogs. A 5-year-old, spayed female miniature schnauzer developed a swelling below the nasal canthus of left eye. Plain radiograph demonstrated a 1.5 cm diameter of radiolucent lesion on the maxillary bone anteroventral to the eye, and contrast dacryocystorhinography confirmed an obstructed nasolarcrimal duct. The swelling showed poor response to antibiotic treatment but responded well to oral prednisolone. Exploratory surgery revealed a cyst-like structure filled with brown serous fluid. Histopathological examination of the removed cyst revealed a double cuboidal epithelial cyst. The dog recovered rapidly after surgery, and the swelling had not recurred for a 36-month follow-up. It is the first case of periorbital bone epithelial cyst reported in an adult miniature schnauzer.
