Ocular Microbiology and Immunology Group
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2017 OMIG Abstract 27

Treatment of Acanthamoeba with a Novel Far-UV Sterilray^TM
Wavelength (222nm) Lamp

J. James Rowsey, MD¹, Capritta Roberts, DO², Louis Michaelos, DO³,  John Michaelos, MD¹, Brad Fouraker, MD⁴, Darlene Miller⁵, S. Edward Neister⁶, John Neister⁶, Steve Hudson ^6
1St. Michael’s Eye and Laser Institute, Largo, Florida; ²Perich Eye Center, New Port Richey, Florida;
³Larkin Hospital Department of Ophthalmology, Miami, Florida;
⁴Brandon Eye Center, Brandon, Florida; ⁵Bascom Palmer Department of Ophthalmology, Miami, Florida;
⁶Ocular Photo Disinfection, LLC, Somersworth, New Hampshire

Purpose: To determine if ocular isolates of Acanthamoeba cysts can be eradicated by a novel FAR-UV Sterilray^TM (222nm) wavelength of light that would be safe for the corneal  endothelium (under 60 minutes of surface treatment)

Methods:  Acanthamoeba  trophozoites were inoculated on E.coli plates and then induced to form a uniform colony of cysts.  When all cysts were present the plates were treated with a collimated beam of increasing doses of  1.9-3mW/cm2 FAR UV Sterilray^TM (222nm) light by increasing exposure periods of: 20 sec (38mJ), 60sec (114mJ), 5 min (570mJ), 6.67 min (1201mJ), 10 min (1801mJ), 13 min (2400mJ), and 30 minutes (5401mJ).  The treated plate areas were reflooded with E.coli nutrient saline and in 48 hours had a 6 mm section trephined and the agar subcultured on E.coli nutrient plates.  Growth of new trophozoites was considered dose/time treatment failure and lack of reversion to trophozoites was deemed a successful  treatment time.

Results:  Acanthamoeba cysts treated for 114mJ or less demonstrated reversion to trophozoites, or treatment failure.   5 minutes (901mJoules) or greater exposure demonstrated no growth of trophozoites, indicating that all cysts had been killed.  Some cysts escaped killing at 10 minutes but no viable organisms were noted at 13 min (2400mJ) or 30 minutes (5401 mJ).

Conclusions:  A novel FAR-UV  Sterilray^TM (222nm) wavelength has been demonstrated to kill Acanthamoeba cysts at a treatment time that would allow for safety of the corneal endothelium.  We have IRB approval to treat ocular Acanthamoeba infections with this new modality. 

2017 Agenda and Abstracts | < Previous