OT-551 HCl (intraperitoneally injected; rats; approximately 30 min prior to a 6 h exposure to 2700 lux white fluorescent light) significantly reduced the number of RPE cell nuclei in light-exposed eyes from water-treated animals. RPE damage index was significantly lower in the animals treated with any dose of OT-551 HCl compared to water-treated animals both in the inferior and superior hemispheres. Systemic administration of OT-551 HCl provides RPE cell protection against acute light damage.[1]