Visual Outcomes after Proton Beam Irradiation for XXXX Involving the Fovea.

@entity1 @entity1018 @entity5 @entity1713 @entity1020 @entity320
PURPOSE: To report visual outcomes in @entity1 undergoing proton beam irradiation of @entity5 located within 1 disc diameter of the fovea. DESIGN: Retrospective review. @entity1 : @entity1 with @entity320 involving the fovea treated with proton beam therapy between 1975 and  2009. METHODS: Three hundred fifty-one @entity1 with @entity320 located 1 disc diameter (DD) or less from the fovea and more than 1 DD away from the optic nerve were included in this study. In a subgroup of 203 of the @entity1 with small and medium @entity320 , the effect of a reduced dose of radiation, 50 Gy (relative biological effectiveness [RBE]) versus 70 Gy (RBE), on visual outcomes was analyzed. The Kaplan-Meier method and Cox regression analysis were performed to calculate cumulative rates of @entity1018 and to assess risk factors for @entity1018 , respectively. MAIN OUTCOME MEASURES: Visual acuity and radiation complications, which included radiation @entity1020 , papillopathy, @entity1713 , and rubeosis, were assessed. RESULTS: Three hundred fifty-one @entity1 were included in this study with a mean follow-up time of 68.7 months. More than one-third of @entity1 (35.5%) retained 20/200 or better vision 5 years after proton beam irradiation. For those @entity1 with a baseline visual acuity of 20/40 or better, 16.2% of @entity1 retained this level of vision 5 years after proton beam irradiation. @entity5 height less than 5 mm and baseline visual acuity 20/40 or better were associated significantly with a better visual outcome (P < 0.001). More than two-thirds (70.4%) of @entity1 receiving 50 Gy (RBE) and nearly half (45.1%) of @entity1 receiving 70 Gy (RBE) retained 20/200 or better vision 5 years after treatment, but this difference was not significant. Approximately 20% of @entity1 with these smaller macular @entity5 retained 20/40 vision or better 5 years after irradiation. CONCLUSIONS: The results of this retrospective analysis demonstrate that despite receiving a full dose of radiation to the fovea, many @entity1 with @entity320 with foveal involvement maintain useful vision. A radiation dose reduction from 70 to 50 Gy (RBE) did not seem to increase the proportion of @entity1 who retain usable vision.
