Characterization of Night Vision Impairment in Choroideremia and Short-Term Vitamin A Supplementation: The Dark-Adapted Retinal Function Response in Choroideremia (DARC) Study
试验速览
- 阶段
- 不适用
- 状态
- 撤回
- 试验地点
- 2
- 主要终点
- Change in dark-adapted macular visual field sensitivity
研究概览
简要总结
Choroideremia (CHM) is an inherited retinal disorder that causes progressive vision loss, ultimately leading to complete blindness. The first symptom is generally night blindness, although, to date, little is known about the extent, type, pattern, and progression of dark-adapted visual function measures in CHM patients. We hypothesize that one of the key events causing night blindness in CHM is deficiency in the chromophore of the rod visual pigment, rhodopsin. We propose that this deficiency is at least in part due to inadequate delivery of vitamin A (all-trans-retinol) to the photoreceptors (PRs) from the ailing retinal pigment epithelium (RPE), characteristic of CHM. We hypothesize that increased availability of vitamin A would potentiate its entry into the RPE-mediated visual cycle, ultimately enabling delivery to the PRs. This would in turn allow rods to perform better by partially overcoming the RPE damage and the impaired chromophore recycling that we postulate exists in CHM. The goals of this proposal are: (1) to test the hypothesis that oral vitamin A supplementation can improve night time and peripheral vision in CHM patients, and (2) to provide detailed characterization of dark-adapted visual function outcome measures to guide interventional CHM trials.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Treatment
- 盲法
- None
入排标准
- 年龄范围
- 15 Years 至 —（Child, Adult, Older Adult）
- 性别
- Male
- 接受健康志愿者
- 是
入选标准
- •males at least 15 years of age with molecularly-confirmed diagnosis of choroideremia
排除标准
- •inability to participate in visual field testing reliably and reproducibly
结局指标
主要结局
Change in dark-adapted macular visual field sensitivity
时间窗: Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period
Dark-adapted macular visual field sensitivity will be measured using the Medmont dark-adapted chromatic perimeter.
Change in dark-adapted full-field visual field sensitivity
时间窗: Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period
Dark-adapted full-field visual field sensitivity will be measured using the Medmont dark-adapted chromatic perimeter.
Change in dark adaptometry
时间窗: Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period
Dark adaptometry will be measured using the MacuLogix AdaptDx dark adaptometer.
次要结局
- Change in retinal pigmented epithelium (RPE) atrophy by optical coherence tomography(Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period)
- Change in retinal pigmented epithelium (RPE) atrophy by color photography(Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period)
- Change in full-field light-adapted visual field sensitivity(Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period)
- Change in retinal pigmented epithelium (RPE) atrophy by fundus autofluorescence(Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period)
- Change in best corrected visual acuity(Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period)
- Change in low luminance visual acuity(Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period)
- Change in retinal pigmented epithelium (RPE) atrophy by fundoscopy(Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period)
- Change in liver function(Measurements at 0, 4, and 8 months)
- Change in serum vitamin A levels(Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period)
- Change in light-adapted macular visual field sensitivity(Measurements at 0, 4, and 8 months. The 0 months measurement will serve as the baseline. The 4 month measurement will assess change due to vitamin A supplementation. The 8 month measurement will assess reversal of this change following washout period)