Optical biometric measurements in patients with previous COVID-19 treatment

We aimed to compare optical biometric measurements using optical biometry in patients with previously received COVID-19 treatment and a control group.

In this cross-sectional study, patients with previously received COVID-19 treatment formed the COVID-19 group and age- and sex-matched healthy participants formed the control group. Optical biometric measurements including keratometry, corneal astigmatism, astigmatic axis, central corneal thickness, anterior chamber depth, and axial length were made using a Nidek optical biometer (AL-Scan; Nidek Co., Ltd., Japan).

Measurements of keratometry (p = 0.79), corneal astigmatism (p = 0.41), axial length (p = 0.96), anterior chamber depth (p = 0.59), and central corneal thickness (p = 0.37) were similar between the COVID-19 and control groups. The astigmatic axis type taken from 2.4 mm of the cornea showed significant difference between the two groups (p = 0.02, χ²), while the measurements taken from 3.3 mm of the cornea were similar (p = 0.10, χ²). In the subgroup analysis, axial length, anterior chamber depth, and central corneal thickness measurements were found to be statistically significantly higher in male patients of the COVID-19 group (p = 0.02; p = 0.001; p = 0.02, t test).

The changes in optical biometric measurements found in our study were due to the fact that COVID-19 is more frequent and severe in males, SARS-CoV‑2 can attach to the cornea via ACE‑2 receptors, and favipiravir can reach the aqueous humor. To our knowledge, there is no study on this subject to date, and therefore more research is needed to shed light on this topic.