Abstract
Purpose :
Drusen are a hallmark of age-related macular degeneration (AMD). Yet, objective visual function measurements in the area of drusen are rare. We investigate correlations between the presence and localization of drusen with multifocal electroretinogram (mfERG) examinations in patients with early and intermediate AMD (iAMD).
Methods :
Six patients with iAMD were examined. Subjective visual function including Best Corrected Visual Acuity (BCVA), Low Contrast Visual Acuity (LCVA), and Low Luminance Visual Acuity (LLVA), was tested. Morphology was examined by spectral domain optical coherence tomography (SD-OCT, Heidelberg). OCT images were segmented automatically (Heyex, Heidelberg), followed by manual correction of the segmentation to ensure accuracy in drusen assessment. Objective visual function was measured by mfERG to assess en-face retinal function in ETDRS sectors. This study adheres to the Declaration of Helsinki.
Results :
All eyes included had iAMD, AREDS grade 2. Mean BCVA was 83.83 ± 7.3 letters, mean LLVA was 67.17 ± 11.9 letters, mean LCVA was 66 ± 5.4 letters. Mean drusen volume in the ETDRS grid field was 0.49 ± 0.068 mm^3. In a descriptive analysis, the highest drusen volume in the central foveal area (0.036 mm^3) correlated with the lowest central amplitude in mfERG (48.84 nV). This was also seen in other macular areas. Divided in two groups, those eyes with a higher central drusen volume had significantly (p< 0.05) lower mean mfERG amplitudes (60.3 ± 29 nV), than eyes with a lower central drusen volume (98 ± 15 nV). Subjective central visual acuity and central mfERG amplitudes did not correlate significantly.
Conclusions :
We provide a deeper understanding of the relationships between morphology and location of drusen, subjective visual acuity, and objective visual function in mfERG. We show that objective visual function is reduced in macular areas with pronounced drusen. This correlation does not necessarily imply for subjective visual function. Our findings may contribute to a better understanding and more targeted functional evaluation in iAMD patients, especially in clinical trials.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.