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Updated: Sep 17, 2025
Author Spotlight: Ex Vivo OCT-Based Multimodal Imaging of Human Donor Eyes for Research into Age-Related Macular Degeneration
Published on: May 26, 2023
Histological Assessment of Foveal Mechanical Instability and Potential Implications for Macular Diseases
Isabela Martins Melo1,2, Jeffrey D Messinger3, Christine A Curcio3
1Department of Ophthalmology, St. Michael's Hospital/Unity Health Toronto, Toronto, Ontario, Canada.
Purpose:
To assess areas of mechanical instability in the fovea based on a review of artifactual separations of histological sections.
Methods:
A collection of annotated high-resolution retinal histological sections of aged donors was assessed for tissue disruptions in the fovea. Sections belong to Project MACULA (https://projectmacula.org).
Results:
Sections (mean length, 7467 ± 491 µm) through 75 foveas were analyzed (61% [46/75] from females; mean age at death, 81.3 years). Of these, 68% (51/75) were normal-aged, and 32% (24/75) showed early non-neovascular AMD. Separation of the neurosensory retina from the RPE occurred in 96% of sections (72/75). A break between the photoreceptor inner and outer segments was observed in 57% of cases (41/72), and bacillary layer detachment was observed in 15% (11/72), primarily involving the subfoveal region. Henle fiber layer disruptions were observed in 64% of sections (48/75), being around the Müller cell cone (MCC) in 90% of cases (43/48) and extending to cone photoreceptor cell bodies in 58% (28/48). Cystic changes at the MCC occurred in 50% of sections (38/75), with partial or complete disinsertion of the MCC in 47% of these (18/38).
Conclusions:
Histological sections from normal-aged and early AMD eyes exhibit frequent tissue disruptions from post mortem handling, corresponding with regions of separation observed on OCT scans of various vitreoretinal diseases. Findings suggest that foveal areas of low mechanical stability may manifest as common ex vivo artifactual disruptions. Observing how foveal tissue breaks down post mortem may provide greater insight into the pathophysiology of different vitreoretinal diseases.
Insights
Post-mortem handling causes foveal tissue disruptions, revealing areas of low mechanical stability in the retina. These findings may illuminate the pathology of vitreoretinal diseases.
Area of Science:
- Ophthalmology
- Retinal Histology
- Biomechanical Analysis
Background:
- The fovea's mechanical properties are crucial for visual function.
- Understanding foveal biomechanics can provide insights into retinal diseases.
Purpose of the Study:
- To identify areas of mechanical instability within the fovea.
- To correlate artifactual separations in histological sections with potential weaknesses.
Main Methods:
- Analysis of high-resolution histological sections from aged human donor eyes (n=75).
- Assessment of tissue disruptions in the fovea, including retinal-RPE separation and photoreceptor layer integrity.
- Categorization of samples into normal-aged and early age-related macular degeneration (AMD) groups.
Main Results:
- Significant artifactual separations were observed in 96% of sections (retinal-RPE separation).
- Disruptions in the photoreceptor inner/outer segments (57%) and Henle fiber layer (64%) were common.
- Müller cell cone (MCC) involvement, including cystic changes and disinsertion, occurred in 50% of sections.
Conclusions:
- Frequent post-mortem tissue disruptions in histological sections indicate areas of low mechanical stability in the fovea.
- These artifactual findings may mimic pathological changes seen in OCT scans of vitreoretinal diseases.
- Studying ex vivo foveal tissue breakdown offers insights into the pathophysiology of retinal diseases.
