Sodium Hyaluronate-Induced Ocular Hypertension in Rats Damages the Direction-Selective Circuit and Inner/Outer Retinal Plexiform Layers

Purpose: To assess the changes in retinal morphology in a rat model of chronic glaucoma induced by ocular hypertension. Methods: Intraocular pressure (IOP) was surgically increased through weekly injections of sodium hyaluronate (HYA) in the anterior eye chamber of the left eye of male Wistar rats, whereas the right eyes were sham operated (salt solution). During the 10-week experimental period, IOP was measured weekly with a rebound tonometer. Retinal cryosections were prepared for histological/immunohistochemical analysis and morphometry. Results: IOP was higher in HYA-treated eyes than in sham-operated eyes along the 10-week period, which was significant from the fourth to the nineth week. Ocular hypertension in HYA-treated eyes was associated with morphologic and morphometric changes in bipolar cells, ON-OFF direction-selective ganglion cells, ON/OFF starburst amacrine cells, and inner plexiform layer sublamina. Conclusions: Serial HYA treatment in the rat anterior eye chamber results in mild-to-moderate elevated and sustained IOP and ganglion cell death, which mimics most human open-angle glaucoma hallmarks. The reduced number of direction-selective ganglion cells and starburst amacrine cells accompanied by a deteriorated ON/OFF plexus in this glaucoma model could lend insight to the abnormalities in motion perception observed in patients with glaucoma.Supported by the Spanish Ministry of Science and Innovation (MICINN-FEDER PID2019-106230RB-I00), 2), Institute of Health Carlos III (General Subdirection of Networks and Cooperative Research Centers RETICs OFTARED 2012-2021) co-financed by the European Regional Development fund (RD16/0008/0016 [Alicante] and RD16/0008/0022 [Valencia]), Asociación Retina Asturias (ASOCIACIONRETINA1-20I), Generalitat Valenciana (IDIFEDER/2017/064), and the Research funds from both Department of Surgery (Ophthalmology Unit) and Cellular-Molecular Ophthalmobiology Group of the University of Valencia (Spain)

Highly invasive and poorly differentiated corneal squamous cell carcinoma in a dog

Abstract Background Primary corneal tumors are unusual in dogs although there has been a rise in the prevalence of canine corneal squamous cell carcinoma in the past decades due to different factors. Exposure to ultraviolet radiation, presence of chronic keratitis or history of superficial trauma are some of them. We report for the first time a highly infiltrative corneal neoplasia with both exophytic and deep stromal growth, which presented atypical histologic features of a squamous cell carcinoma. Case presentation An adult male French bulldog was referred with an exophytic, pink to white gelatinous mass occupying approximately 70% of the central cornea on the right eye. Histological findings from the excisional biopsy were consistent with corneal carcinoma and transconjunctival enucleation was performed at the request of the owner. A final diagnosis of primary corneal squamous cell carcinoma was done based on the squamous differentiation observed in the neoplastic cells of the superficial layers. However, cells in deeper layers were less differentiated, showed pseudoacinar formations and did not expressed marker for stratified squamous epithelium (i.e., cytokeratin 5/6). The dramatic thickening of the cornea and the fact of observing neoplastic cells almost at the level of the Descemet’s membrane make this case very unusual as the squamous cell carcinoma in dogs tends to involve the superficial stroma or colonize the corneal surface as an exophytic lesion. Conclusions Based on the histological findings, a high infiltrative and poorly differentiated corneal squamous cell carcinoma was diagnosed. In terms of clinical relevance, our results suggest that corneal lesions compatible with neoplasia need an early diagnosis in order to prevent the aggressive growth of the tumor and the enucleation of the eye

Comparison of two sedation protocols for long electroretinography in horses using the Koijman electrode

Abstract Background In modern times, horses are utilized not only for labour and transportation purposes but also for recreational activities such as competition and pleasure riding. In these various pursuits, the role of vision plays a crucial role. Electroretinography is the most used test to diagnose diseases of the retinal outer segment. There is a wide variety of devices to perform the electroretinography differing one from each other in the corneal electrode and the light stimulation. The Koijman electrode has been tested in dogs but not in horses. The main purpose of this study was to compare electroretinography parameters from horses sedated with detomidine alone or in combination with butorphanol, during a standardized protocol using the Koijman electrode and RETI-port® system. Seven mares were allocated to the detomidine and detomidine plus butorphanol group in a randomised, controlled, crossover study. Friedman and Willcoxon-signed ranked tests were used to compare the electroretinogram parameters. A Student’s t-test was used to compare differences in the number of artefacts to valid values ratio obtained under both sedation protocols. Results Dark adaptation peaked after 16 min under scotopic conditions in both groups. No significant differences in electroretinogram parameters between groups were observed. During the mixed rod and cone response evaluation under scotopic conditions, all mares made a movement of the head resulting in a high number of artefacts. The detomidine plus butorphanol group showed a non-significant tendency to have fewer artefacts and a longer duration of sedation compared to the detomidine group. Conclusions Detomidine alone or combined with butorphanol may be suitable to use Koijman electrode and the RETI-port® to perform a standardized long protocol in horses with some adaptations

Composición basada en la actividad antioxidante de la enzima superóxido dismutasa y su aplicación en enfermedades oculares

La presente invención se refiere a la composición que contiene una enzima perteneciente al grupo de las superóxido dismutasas (SOD), o bien cualquier mímico de la SOD y similares junto con ácido hialurónico y EDTA. Dicha composición forma parte de una formulación farmacéutica la cual promueve o mantiene la salud ocular a través de la inhibición del daño celular y tisular producido por radicales libres, por lo que es útil en el tratamiento y/o prevención de enfermedades oculares que cursan con estrés oxidativo, o como coadyuvante de otros tratamientos existentes, así como posoperatorios para tratar y/o prevenir reacciones adversas inflamatorias o estrés oxidativoPeer reviewedFundación para el fomento de la investigación sanitaria y biomédica de la Comunidad Valenciana (FISABIO), Universitat Politècnica de València, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Cardenal Herrera CEU San Pablo, Universitat de ValènciaA1 Solicitud de patente con informe sobre el estado de la técnic