Comparison of the in vitro anticollagenase efficacy of homologous serum and plasma on degradation of corneas of cats, dogs, and horses

Abstract

OBJECTIVE To compare the anticollagenase efficacy of fresh feline, canine, and equine serum and plasma on in vitro corneal degradation. SAMPLE Grossly normal corneas from recently euthanized dogs, cats, and horses and fresh serum and plasma from healthy dogs, cats, and horses. PROCEDURES Serum and plasma were pooled by species and used for in vitro experiments. Corneas were collected and stored at -80°C. Sections of cornea were dried, weighed, and incubated in saline (0.9% NaCl) solution with clostridial collagenase and homologous fresh serum or plasma. Corneal degradation was assessed as the percentage of corneal weight loss and hydroxyproline concentration, compared with results for positive and negative control samples. RESULTS Homologous fresh serum and plasma significantly reduced the percentage of corneal weight loss, compared with results for positive control samples. No significant difference was found in percentage of corneal weight loss between incubation with serum or plasma for feline, canine, and equine corneas. Canine serum and plasma significantly reduced hydroxyproline concentrations, whereas inclusion of feline and equine serum or plasma did not, compared with results for positive control samples. Hydroxyproline concentrations were moderately correlated with percentage of corneal weight loss for feline samples and weakly correlated for equine samples, but they were not correlated for canine samples. CONCLUSIONS AND CLINICAL RELEVANCE In this study, the anticollagenase efficacy of fresh feline, canine, and equine serum was not different from that of plasma. Plasma should be an acceptable substitute for serum in the topical treatment of keratomalacia.

Squishy matters – Corneal mechanobiology in health and disease

“…However, measurement of stromal elastic modulus was not performed. Enzymes that digest collagens such as amylase and collagenase contribute to the pathology of keratoconus and keratomalacia and it is thus important to quantify the biomechanical changes resulting from them ( Collier et al, 2000 ; Conway et al, 2016 ; Donovan et al, 2021 ; Kazaili et al, 2021 ; Kimmitt et al, 2018 ; Mackiewicz et al, 2006 ). Unsurprisingly, elastic modulus and collagen fibril diameter as measured with AFM reduced in a dose-dependent manner when ex vivo porcine corneas were incubated with amylase or collagenase; cryosectioned tissue was used for AFM measurement thus impacting the absolute elastic modulus values ( Kazaili et al, 2021 ).…”

Use of autologous serum or Vizoovet to improve healing rates of spontaneous chronic corneal epithelial defects after diamond burr debridement in dogs

“…Autologous or homologous serum has been used for quite some time in the treatment of corneal disease, mainly keratomalacia 11‐16 . The alpha‐2 macroglobulin found within serum can be extremely helpful in slowing the collagenolytic process found with certain cases of bacterial keratitis.…”

In vitro assessment of the long‐term stability of the inhibitory effects of canine and feline plasma on MMP 2 and 9

“…The use of serum to counteract corneal digestion by collagenases is well established . The anti‐collagenase efficacy of fresh plasma and fresh frozen plasma has recently been shown to be equivalent to serum, obviating the logistic and animal‐related difficulties associated with collecting serum from animals with ulcerative keratitis. There have been studies evaluating the long‐term stability of frozen serum .…”