Study details early detection of vision loss in AMD
Researchers from the UKB Eye Clinic, in cooperation with the University of Bonn and in close collaboration with basic and clinical scientists, have examined patients with early forms of AMD. The researchers focused on the so-called iRORA lesions, which are very early anatomical signs of retinal damage.
(Image credit: AdobeStock/KMPZZZ)
Researchers at the University Hospital Bonn (UKB), working in cooperation with the University of Bonn have shown for the first time that certain early changes in patients with age-related macular degeneration (AMD) can lead to a measurable local loss of vision.
According to a Universitatsklinikum Boon news release,1 their findings could help to improve the treatment and monitoring of AMD in older patients, which otherwise slowly leads to central blindness, and to test new therapies.
The researchers noted in the news release that AMD mainly affects elderly people. Untreated, the disease results in a loss of central vision, reducing the quality of life in patients diagnosed with the disease. Researchers worldwide are seeking ways to improve the early detection and treatment of this disease before major losses occur.
Researchers from the UKB Eye Clinic, in cooperation with the University of Bonn and in close collaboration with basic and clinical scientists, have examined patients with early forms of AMD. The researchers focused on the so-called iRORA lesions, which are very early anatomical signs of retinal damage.2
"We used the microperimetry method to precisely measure the visual acuity at these affected areas of the retina," explain Julius Ameln, PhD, Marlene Saßmannshausen, MD, and Leon von der Emde, MD, who carried out the examinations, which included measuring the sensitivity of the retina to light stimuli in order to identify visual impairments.
As the affected retinal areas are smaller than 250 µm, routine clinical devices reach their limits. The process is aided by a high-resolution research instrument developed in Bonn, known as an adaptive optics scanning light ophthalmoscope (AOSLO).1
"It enables imaging of the retina with microscopic resolution and allows functional testing of small areas down to individual photoreceptors," Wolf Harmening, PHD, head of the AOSLO laboratory at the UKB Eye Hospital and member of the Transdisciplinary Research Area (TRA) Life & Health at the University of Bonn, said in the news release.
The researchers found the visual acuity in the areas of the lesions was markedly reduced. With the standard method, the loss was on average 7 units compared to a control region. With the precise AOSLO method, the loss was 20, which corresponds to a reduction in light sensitivity by a factor of 100.2
The researchers reported the impact of iRORA lesions on retinal function in 4 patients with iAMD. According to the researchers, a structural precursor for GA development, iRORA can also be connected to functional impairments detected by AOSLO-MP.
The researchers point out the results show iRORA lesions indeed have a great impact on vision. This early retinal damage could serve as a marker to improve monitoring of the progression of the disease to treat it at an early stage. The researchers further pointed out the results of their work take a step forward to an improved understanding of how the late form of dry AMD develops with the formation of extensive retinal damage.1
"Our investigations show that even these early lesions can contribute to a very localized but nonetheless significant deterioration in vision in our patients," Harmening said in the news release.
"This makes them a potential marker that can help to better monitor the progression of AMD and treat it at an earlier stage," Frank Holz, MD, director of the UKB Eye Clinic, said in the news release.
“This pilot study revealed a statistically significant and severe decrease in retinal sensitivity at iRORA lesions in iAMD patients,” the researchers concluded in the study. “Larger cohort studies will be necessary to validate our findings.”
