Corneal stroma analysis and related ocular manifestations in recovered COVID-19 patients.

Abstract

Purpose : Currently, there is a lack of comprehensive research on the lasting impact of SARS-CoV-2 on the cornea and keratorefractive surgeries. Thus, we conducted a detailed cohort study to evaluate the dynamic alterations in corneal immune responses, mid-stromal nerves, corneal density, and cellular configurations post COVID-19 recovery, alongside evaluating the safety and efficacy of Small Incision Lenticule Extraction (SMILE) surgery.

Methods : Participants included post-COVID-19 patients (recovered within 135 days) and healthy controls (HC), both groups undergoing SMILE surgery. Fresh corneal lenticules from COVID-19-recovered patients and HC after SMILE surgery were obtained to validate SARS-CoV-2 susceptibility, morphological changes, and immune response of the corneal stroma. Corneal density was measured using Pentacam HR. Corneal epithelium thickness and endothelium parameters were evaluated by wide-field optical coherence tomography (OCT) and non-contact specular microscopy (SP3000), respectively. Participants were monitored for up to three months following their SMILE surgery.

Results : Our initial findings revealed the cornea's susceptibility to SARS-CoV-2, evidenced by the detection of SARS-CoV-2 receptors (CD147 and ACE2) and remnants of spike proteins in the corneal lenticules of post-recovery patients (4 out of 58). Moreover, SARS-CoV-2 prompted dynamic immune responses in the corneal stroma after different recovered durations. Elevated level of inflammatory marker IL-6 was observed 45-75 days post-recovery, which diminished around day 105. Concurrently, changes in corneal mid-stromal nerve length and branching patterns were observed, peaking around days 60-75 and normalizing by day 135. Corneal density within zones 0-2 and 2-6 exhibited a similar pattern, first increasing at around 75 days and then decreasing to a level lower than HC at about 135 days. Furthermore, an early surge followed by a decline was also observed in the hexagonal cell ratio in endothelial cells post-recovery, while epithelial thickness remained stable. Importantly, these variations did not impact the efficacy, safety, or predictability of post-recovery SMILE surgery.

Conclusions : SARS-CoV-2 induces temporal alterations in corneal stromal morphology and function post-recovery, which do not affect the outcomes of post-recovery SMILE surgery.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.