Summary: A new study reveals that early changes in age-related macular degeneration (AMD) can lead to measurable local vision loss. Researchers used advanced imaging to find that iRORA lesions, early signs of retinal damage, significantly reduce visual acuity.
This discovery could enhance the monitoring and treatment of AMD, potentially preventing severe vision loss. The findings offer hope for earlier intervention in this progressive eye disease.
Key Facts:
Source: University of Bonn
New research by the University Hospital Bonn (UKB) in cooperation with the University of Bonn has 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.
This discovery could help to improve the treatment and monitoring of this eye disease in older patients, which otherwise slowly leads to central blindness, and to test new therapies.
AMD mainly affects elderly people. If left untreated, the disease leads to a progressive loss of central vision, which significantly impairs everyday activities such as reading or driving. Researchers around the world are intensively searching for ways to improve the early detection and treatment of this disease before major losses occur.
A research team from the UKB Eye Clinic, in cooperation with the University of Bonn and in close collaboration with basic and clinical scientists, has specifically 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.
The results are published in BMJ Open Ophthalmology.
“We used the microperimetry method to precisely measure the visual acuity at these affected areas of the retina,” explain Julius Ameln, Dr. Marlene Saßmannshausen and Dr. Leon von der Emde, who carried out the examinations.
This involves measuring the sensitivity of the retina to light stimuli in order to identify visual impairments. As the affected retinal areas are smaller than 250 micrometers, routine clinical devices reach their limits.
A high-resolution research instrument developed in Bonn, known as an adaptive optics scanning light ophthalmoscope (AOSLO), helps out.
“It enables imaging of the retina with microscopic resolution and allows functional testing of small areas down to individual photoreceptors,” says Dr. Wolf Harmening, 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.
The results were clear: 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.
These results illustrate that iRORA lesions already have a significant impact on vision. This early retinal damage could serve as a marker to better monitor the progression of the disease and treat it at an early stage.
The results of this study are a further step toward better understanding how the late form of dry AMD develops with the formation of extensive retinal damage.
“Our investigations show that even these early lesions can contribute to a very localized but nonetheless significant deterioration in vision in our patients,” explains Dr. Wolf Harmening.
“This makes them a potential marker that can help to better monitor the progression of AMD and treat it at an earlier stage,” adds Prof. Dr. Frank Holz, Director of the UKB Eye Clinic.
Author: Inka Väth
Source: University of Bonn
Contact: Inka Väth – University of Bonn
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Assessment of local sensitivity in incomplete retinal pigment epithelium and outer retinal atrophy (iRORA) lesions in intermediate age-related macular degeneration (iAMD)” by Julius Ameln et al. BMJ Open Ophthalmology
Abstract
Assessment of local sensitivity in incomplete retinal pigment epithelium and outer retinal atrophy (iRORA) lesions in intermediate age-related macular degeneration (iAMD)
Lesions of incomplete retinal pigment epithelium and outer retinal atrophy (iRORA) are associated with disease progression in age-related macular degeneration. However, the corresponding functional impact of these precursor lesions is unknown.
We present a cross-sectional study of four patients employing clinical-grade MAIA (stimulus size: 0.43°, ~125 µm) and adaptive optics scanning light ophthalmoscope (AOSLO, stimulus size 0.07°, ~20 µm) based microperimetry (MP) to assess the specific impact of iRORA lesions on retinal sensitivity.
AOSLO imaging showed overall reduced photoreceptor reflectivity and patches of hyporeflective regions at drusen with interspersed hyper-reflective foci in iRORA regions. MAIA-MP yielded an average retinal sensitivity loss of −7.3±3.1 dB at iRORA lesions compared with the in-eye control. With AOSLO-MP, the corresponding sensitivity loss was 20.1±4.8 dB.
We demonstrated that iRORA lesions are associated with a severe impairment in retinal sensitivity. Larger cohort studies will be necessary to validate our findings.
