Biological effects of stored platelet-rich plasma eye-drops in corneal wound healing

BACKGROUND/AIMS

This study aimed to assess the efficacy and sterility of stored platelet-rich plasma (PRP) eye-drops for corneal epithelial wound healing compared with those of autologous serum (AS) eye-drops.

METHODS

At our single institution, PRP and AS eye-drops were prepared using peripheral blood obtained from six healthy volunteers and stored at 4°C. Platelet and leucocyte counts and transforming growth factor (TGF)-β1, epidermal growth factor (EGF), and fibronectin levels were assessed during storage for up to 4 weeks. Sterility was assessed by culturing 4-week poststorage samples. PRP, AS, and phosphate-buffered saline (PBS) eye-drop efficacies were compared using corneal epithelial wound healing assays in vitro and in vivo and monitoring wound areas under a microscope every 3 hours.

RESULTS

Higher platelet and lower leucocyte counts were seen in PRP than in whole blood on the day of preparation. After storage, TGF-β1, EGF, and fibronectin levels were significantly higher in PRP than in AS eye-drops. In vitro and in vivo, PRP eye-drops used on the day of preparation significantly promoted corneal epithelial wound healing compared with PBS. Moreover, PRP eye-drops stored for 4 weeks significantly promoted corneal wound healing compared with PBS and AS eye-drops.

CONCLUSION

PRP eye-drops stored at 4°C for 4 weeks promoted corneal epithelial wound healing with higher levels of growth factors than those observed in AS eye-drops, while maintaining sterility, suggesting that this preparation satisfies the unmet medical needs in the treatment of refractory keratoconjunctival epithelial disorders.

The influence of electromagnetic radiation on the measurement behaviour of the triggerfish® contact lens sensor

BACKGROUND

To assess a possible signal drift, noise and influences of electromagnetic radiation on the measurement behaviour of the Triggerfish® contact lens sensor, which might be mistaken as IOP fluctuations.

METHODS

Contact lens sensors (Triggerfish®, SENSIMED AG, Lausanne, Switzerland) were fixed in a water bath. To reduce any external electromagnetic impulses, all plugs were removed from the sockets, no lights were switched on and no electronic devices, except a temperature logger were left in the test room. For 24 h signal drift, noise and the influences of a cordless telephone (Ascom d43 DECT Handset, EU DECT 1880-1900 MHz, Ascom Wireless, Baar, Switzerland), a smartphone (Sony Xperia Go ST27i, Sony Corporation, Tokyo, Japan) and a computer (Hewlett-Packard ProBook 650 15,6″ - D9S33AV, Hewlett-Packard Inc., Palo Alto, USA) on the measuring profile were analysed.

RESULTS

Twenty-four-hour measurements without provoked external electromagnetic impulses yielded a profile without any signal drift and 8.2 mV eq noise. During the activation of the cordless telephone a maximum measurement variation of 3.2 mV eq. (4.1-7.3), smartphone 1.8 mV eq. (4.7-6.5) and computer 1.4 mV eq. (6.3-7.7) were observed.

CONCLUSIONS

During 24-h measurements there was no signal drift and a very low noise. Patients concerned about electronic devices possibly interfering with the measurements of the contact lens sensor, can be informed, that the use of their cordless telephone, smartphone or computer does not cause any problems. The amount of the signal noise might help to define actual IOP fluctuations. Temperature fluctuations might influence the measuring profile.