The link between genes causing age related macular degeneration and changes in the retina and vision

Summary

​​​Age related macular degeneration (AMD) is the commonest cause of vision loss in older individuals. AMD starts with changes that occur in the macula, the centre of the retina of the eye. These changes can be recorded by imaging the retina and we record the progression of AMD based on these changes. In the early stages (Early AMD), these macular changes are minor and affected individuals do not have any vision changes. With time, some eyes tend to have an increase in these macular changes and this stage is called intermediate AMD. Some people with intermediate AMD have difficulty adjusting to dim light while others do not. The amount of time that an individual takes to adjust to change from light to dark can be measured by rod intercept time. Eyes that take longer to adjust from light to dark are more prone to disease worsening to advanced AMD. In advanced AMD, people experience difficulties with their central vision. Near vision and reading vision may be affected before they suffer from central vision loss. At present, we do not know why some people progress to have delayed rod intercept time.  

​At present we know that 52 genes are associated with AMD. In addition, there are other risk factors for AMD such as ageing and smoking. We have studied the retinal changes and visual function in detail in 310 people with AMD of varying severity. We now want to develop polygenic risk scores (PRS) for these individuals by linking genetic risk with macular changes and delays in dark adaptation. The results of this study may help us find out who are at higher risk of progression. We may be able to classify AMD better. This will in turn help us recruit those at high risk of progression to future clinical trials on AMD. ​