Primary Outcome Measures:
- Analysis of retinal structure and function [ Time Frame: 6 years ]
Retinal structure will be analysed using Adaptive optics and SD-OCT and Fundal autofluorescence. This will be correlated with assessment of visual acuity, psychophysical visual assessment, visual mobility, retinal sensitivity and visual fields
Secondary Outcome Measures:
- Quality of Life Questionnaires [ Time Frame: 6 years ]
Assessment of Visual impairment using appropriate, validated questionnaires
- Retinal Sensitivity [ Time Frame: 6 years ]
To be assessed in Microperimetry
- Retinal Structural analysis [ Time Frame: 6 years ]
Retinal Structure analysis with Adaptive Optics
- Fundal Autofluorescence [ Time Frame: 6 years ]
Presence or Absence
- Assessment of Visual Fields [ Time Frame: 6 years ]
Assessment of Visual Fields with analysis of hill of vision
Leber Congenital Amaurosis (LCA) is a diagnosis for a group of severe, autosomal recessively inherited rod - cone dystrophies that typically result in complete visual loss in the third or fourth decade of life. One form, LCA2, is caused by a mutation in the gene encoding RPE56, an RPE-specific 65-kDa isomerase. Non-functional RPE65 results in photoreceptor cells that are unable to respond to light resulting in these patients being visually impaired.
In preparation for human clinical trials, a detailed prospective phenotypic study will be undertaken to investigate the natural history of RPE65-LCA. Such a study will help identify suitable patients for therapeutic intervention. Furthermore through greater phenotyping an optimal window for intervention and specific parameters to help quantify effect and identify clinical end points may have been ascertained .