Harry Spoelstra@HarrySpoelstra
Neuroretinal Alterations in Persistent COVID-19: A Two-Year OCT Follow-Up
🚨New evidence that LongC0VID affects the brain via the retina: 2-year follow-up OCT study shows region-specific inner plexiform layer (IPL) thinning!
➡️The inner plexiform layer (IPL) is defined as the layer in the retina that contains synaptic connections between the axons of bipolar cells and the dendrites of ganglion cells, playing a crucial role in processing motion detection, brightness changes, contrast, and hue recognition.
➡️This prospective longitudinal Spanish study examined long-term retinal changes in 94 patients with persistent COVID-19 (PC/LongC0VID) versus 39 asymptomatic controls using spectral-domain optical coherence tomography (SD-OCT),
Participants underwent detailed ophthalmological assessments at baseline, 1 year (voluntary), and 2 years, focusing on Bruch’s Membrane Opening–Minimum Rim Width and Posterior Pole protocols to measure thicknesses of the retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), and inner plexiform layer (IPL) across macular sectors.
➡️Study findings:
- The most robust between-group difference was greater thinning in the central macular sector (C0) of the IPL in PC patients over two years: −1.429 ± 2.458 μm (PC) vs. +0.207 ± 1.177 μm (controls), p = 0.001, mean difference −1.636 μm, Cohen’s d = −0.79 (medium-to-large effect),
- PC patients showed additional region-specific inner retinal changes (e.g., RNFL outer nasal, GCL central/inner nasal/superior sectors),
- No evidence of generalized or widespread retinal thinning,
- The study did not collect or analyse data on vaccination status or number of reinfections, which the authors listed in the limitations as potential unmeasured confounders that could have influenced the observed neuroretinal changes,
➡️These changes suggest subtle neuroretinal involvement, potentially linked to neuroinflammation or microvascular effects from SARSCoV2.
‼️So, these findings deliver a sobering message: persistent COVID-19 can leave lasting structural fingerprints on the neuroretina, a direct extension of the central nervous system, even two years after initial infection. The significant, region-specific IPL thinning (with a solid effect size) in PC patients, absent in controls, underscores that LongC0VID is not merely a collection of transient symptoms but can involve chronic, measurable neurological damage. This elevates OCT from a research curiosity to a potentially valuable non-invasive window into ongoing CNS involvement, highlighting the urgent need for long-term neurological monitoring, targeted interventions, and further biomarker validation in millions affected by LongC0VID worldwide.
‼️Ignoring these subtle but persistent alterations, reinfections may even potentialize, risks underestimating the true, enduring burden of the pandemic on brain health.
‼️Caution, today, OCT is maybe a promising research tool that might one day help us understand or monitor LongC0VID’s effects on the nervous system (since the retina is part of the brain). But it’s not yet ready to be used as a test to diagnose or detect LongC0VID in clinical practice!
#AvoidSars2 #AvoidReinfections
mdpi.com/2077-0383/15/1…
