Early screening opportunities for diabetic retinopathy
The early stages of DR are often asymptomatic, with many patients experiencing no noticeable changes in their vision. Some individuals may temporarily struggle with reading or seeing distant objects, but these issues tend to be intermittent. As DR progresses, more severe symptoms can appear, including the growth of new blood vessels in the retina. These vessels may leak or bleed, causing dark spots or cobweb-like streaks in the field of vision. Without timely treatment, this bleeding can lead to retinal scarring, detachment, and eventually permanent vision loss.
Visual electrophysiology for diabetic retinopathy
ISCEV guidelines recommend using the ERG to test retinal ischemic conditions. Recent advancements in understanding DR emphasize the importance of tracking retinal neural dysfunction particularly in the disease’s early stages. A variety of tests can aid in identifying these neural changes:
- Multifocal Electroretinogram (mfERG) and Full-Field Electroretinogram (ERG): These tests detect changes in retinal electrical activity, revealing dysfunction before vascular damage occurs. Loss of oscillatory potentials (OPs) and delayed responses are common in diabetes. MfERG results in patients with early DR may highlight localized areas of concern, predicting where new lesions could develop based on changes in response times.
- Full-Field Flicker ERG: Abnormalities, especially at high flicker rates, have been found in patients with early-stage DR. A reduced flicker ERG amplitude and delayed responses indicate retinal dysfunction.
- Photopic Negative Response (PhNR): This ERG component, which is linked to retinal ganglion cells (RGC), may be reduced in patients with DR. This reduction can signal the presence of early retinal ganglion cell dysfunction.
References
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