Comparison of first, second, and third versus the average of six probe-corneal touches for intraocular measurement of two rebound tonometers in healthy horses

The aim of this study was to evaluate the intraocular pressure (IOP) measurements obtained from first, second, and third probe-cornea touch (PCT) and compare them with the average of six PCTs using two rebound tonometers in horses. This study enrolled a total of thirty-eight stallions, comprising of 24 Arabian horses and 14 cross-breeds (with an average age of 8 ± 3 years). The IOP measurements of first, second, and third, as well as the average of six PCTs were obtained using either Tonovet (TV) or Tonovet Plus (TV+) rebound tonometers. The mean differences (95% limits of agreement) between the average of six PCTs and the first, second, and third PCTs were 0.1 (-4.8 to 5), 0.2 (-4.8 to 4.5), and 0.2 (-3.6 to 4.0) mmHg with TV, respectively. With TV+, the differences were 0.3 (-6.6 to 7.2), 1.1 (-8.6 to 10.8), and -0.2 (-3.6 to 4.0) mmHg, respectively. Compared to the average of six PCTs, only 89.5%, 92.1%, and 97.4% of IOP measurements obtained from TV and 78.9%, 73.3%, and 65.8% of IOP measurements obtained from TV+ were within 4 mmHg of the average of six PCTs for first, second, and third PCTs, respectively. In conclusion, the measurement of IOP in the first PCT achieved best agreement with the IOP measurement of six average PCTs. Therefore, the first PCT could be considered as an alternative option for measuring IOP in horses when obtaining an average of six PCTs is not feasible.

Comparative evaluation of platelet-rich plasma, autologous blood serum, and umbilical cord serum for corneal healing after penetrating keratoplasty in New Zealand rabbits

This study aimed to evaluate the effects of platelet-rich plasma (PRP), autologous blood serum (ABS), and umbilical cord serum (UCS) on corneal healing following penetrating keratoplasty (PK). A total of 120 New Zealand white rabbits, forty were designated as donors, while the remaining eighty rabbits were randomly divided into four groups after undergoing PRP Group (n = 20), ABS Group (n = 20), UCS Group (n = 20) and Control Group (n = 20). Corneal opacity score, corneal vascularization, corneal staining, histopathological analysis, and immunohistochemical analysis (including CD4+, CD8+, and major histocompatibility complex [MHC] II) were assessed at postoperative 1, 2, 3, and 12 weeks. The results showed that corneal opacity score and corneal vascularization did not differ significantly among the groups. However, corneal staining was found to be statistically higher in the PRP group (0.40 ± 0.60) compared to the other groups (p = 0.011). Immunohistochemical examination revealed no significant differences in CD4+, CD8+, and MHC II levels among the groups. Notably, in all groups, CD4+, CD8+, and MHC II levels were significantly higher at 12 weeks compared to other time points. PRP, ABS, and UCS demonstrated positive effects on corneal healing after PK. However, among the three products, PRP exhibited a superior healing effect compared to ABS and UCS crucial in the postoperative period following PK procedures, as they significantly impact visual quality, graft transparency, graft survival, and prevention of stromal resorption caused by infections. Despite the avascular nature of the cornea and its immune privilege, failure to resolve epithelial defects (ED) commonly observed after PK can result in irreversible scarring and ulceration, leading to graft rejection. While epithelial defects are observed in 14-100% of cases on the first postoperative day, approximately 3-7% of them persist as non-healing ED in subsequent periods. In conclusion, our study demonstrated that PRP, ABS, and UCS have a positive effect on corneal healing after PK.

The effect of silymarin on mesenteric ischemia-reperfusion injury

OBJECTIVE

To examine the effect of silymarin (SM), a mixture of flavonoids and polyphenols extracted from Silybum marianum, on mesenteric ischemia-reperfusion (I-R) injury in a rat model.

MATERIALS AND METHODS

Fifty rats were randomly divided into 5 groups (n = 10). Group 1 was sham operated, while groups 2-5 were subjected to mesenteric I-R lasting 1 h. Group 2 received isotonic sodium chloride, group 3 received SM (100 mg/kg/day) for 7 days before I-R, group 4 received SM for 7 days after I-R, and group 5 received SM for 7 days both before and after I-R. The rats were sacrificed by exsanguination in groups 1-3 at the 24th hour and groups 4 and 5 were sacrificed on the 7th day of reperfusion. Blood and intestinal specimens were taken for biochemical and pathological evaluations.

RESULTS

Serum superoxide dismutase (SOD) and heat shock protein 70 levels were significantly higher in group 2 (5.24 ± 1.76 U/l and 261.4 ± 16.8 ng/ml) compared to the sham group (2.08 ± 1.76 U/l and 189.9 ± 28.7 ng/ml) (p < 0.001 and p < 0.0001, respectively). However, SOD activity and the extent and severity of the histopathological lesions were significantly less in groups 3 [3.11 ± 1.18 U/l, 1.0 (range 0.0-2.0)], 4 [2.15 ± 0.87 U/l, 1.0 (range 1.0-3.0)], and 5 [1.80 ± 0.61 U/l, 0.5 (range 0.0-2.0)], treated with SM, than in group 2 [5.24 ± 1.76 U/l, 2.0 (range 2.0-3.0)] (p = 0.002, p < 0.001, and p = 0.0001; p < 0.001, p = 0.007, and p = 0.0001, respectively). Also, TNF-α levels were lower in the SM-supplemented groups compared to group 2. Serum thiobarbituric acid-reactive substance concentrations were low in the pre-/posttreatment groups treated with SM compared to group 2. No statistical difference was observed for protein carbonyls between the groups.

CONCLUSION

Our findings suggest that SM therapy may attenuate the oxidative and intestinal damage induced by I-R injuries.