A large review of medical studies looked at a serious eye condition called extensive macular atrophy with pseudodrusen, or EMAP. This condition affects the central part of the retina, which is crucial for sharp, detailed vision. The review combined data from 1,096 eyes to understand how the disease progresses and what signs doctors can look for.
Patients with EMAP experienced a notable decline in their best-corrected visual acuity, which is the sharpest vision they can achieve with glasses or contacts. At the time of diagnosis, their average vision was about 20/80, which is considered moderately impaired. Over an average follow-up of just over two years, their vision worsened by about three lines on a standard eye chart, meaning they lost a significant amount of sight.
The physical structure of the eye also changed dramatically. The area of the macula, the central part of the retina, grew thinner and more damaged. On average, the damaged area increased by about 8.3 square millimeters over nearly four years. Additionally, the layer of tissue under the retina, called the choroid, was thicker than normal in these patients, with an average thickness of about 136 micrometers.
The review also found specific functional problems. Tests showed that the rods, which help with night and side vision, were not working properly. There was also an abnormal response to bright light. Interestingly, the review noted a high prevalence of rheumatic fever in patients from Brazilian cohorts, suggesting a possible systemic link that needs more investigation.
It is important to understand that this study shows associations, not causes. The findings are based on combining existing studies, which can have inconsistencies and biases. The results are limited by the high variability between the different studies included. Despite these limits, identifying these clinical and imaging signs is critical for improving diagnosis and guiding future research for patients with EMAP.