Abstract
Purpose :
The indications for scleral lens (ScCL) wear is no longer confined to those suffering from ocular surface disease or irregular corneas. As the ScCL modality gains popularity, infectious complications associated with ScCL use may also increase. Limited research is available to explain the timecourse of microbial contamination of mulitdose preservative-free, pH-balanced, aqueous isotonic sodium chloride solution, buffered with boric acid and sodium borate saline commonly prescribed off-label for ScCL wear. Currently there is no standard recommendation for discarding the multidose saline bottle after opening. The presence of microorganisms increases the risk of infection development. This study explores the time course of possible microbial contamination of an unused, uncapped bottle of preservative-free saline solution.
Methods :
A brand new bottle of preservative-free saline solution was opened and placed in a work office uncapped. The saline was sampled upon opening and at 3, 7, 14, 30 and 63 d after opening to culture for bacterial and fungal contamination. At each sampling, 20-30 sec hand-washing was followed by transfer of 15 mL saline into a sterile container. For bacterial cultures, 5 mL was inoculated to each of an FA/FN Plus blood culture bottle pair for standard 5 d incubation (BacT/Alert 3D) and 1 mL was plated to Standard Methods Agar and held for 7 d at room temperature. For fungal culture, 0.5 mL was plated to Sabaraud Dextrose Agar to hold for 14 d at 30° C. Plates were observed twice a week for growth
Results :
With the saline bottle kept at 22-25° C and 25-52% humidity, no bacterial or fungal growth was detected in the aerobic or anaerobic blood culture media, Standard Methods Agar, or Sabaraud Dextrose Agar up to 30 d. Cultures of the 63-d sampling are in progress and show no growth to date.
Conclusions :
The identification and enumeration of microorganisms present in sterile saline over a two-month course may play a role in illuminating a more standardized discard time in preventing ScCL associated infection. This study demonstrated that multidose preservative-free saline bottles subjected to minimal handling do not support microorganism growth for at least 30 d after opening. These study findings serve as an important baseline for future studies examining preservative-free saline used during ScCL wear to further explore potential contamination of multidose saline.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.