For people battling severe acne, retinoid isotretinoin can make all the difference. However, the drug is also known to contribute to dry eye—particularly meibomian gland dysfunction. A recent study evaluated the side effects of isotretinoin and found that it also induces epithelial thickening and stromal thinning.

The prospective study included 40 eyes of 40 patients with acne vulgaris who were scheduled to receive oral isotretinoin. The researchers examined each participant with SD-OCT at baseline; at one, three and six months of isotretinoin treatment; and at the third month of washout.

The researchers observed a statistically significant increase in all sectors of the epithelial thickness map between baseline and follow-up visits, except the inferonasal 7mm to 9mm region. Increases in superior, inferior and maximum values in epithelial statistics were significant. At follow-up, stromal statistical values were significant for decreases in the superior, inferior, minimum and maximum values.

The researchers also noted significant differences among central corneal thickness, maximum Ambrosio-related thickness and average pachymetric progression at all follow-ups, as well as significant differences between thinnest pachymetry and surface variance at months three and six. They observed a regression in parameters to baseline values by the third month of washout.

Based on other studies, the researchers suggest isotretinoin induces changes at the molecular level in ocular tissues following systemic exposure to the drug. However, they pointed out in their paper, “There is no experimental study investigating the matrix metalloproteinase-9 (MMP-9) levels or activity in stroma exposed to 13-cis-retinoic acid (a key ingredient of isotretinoin).” They added that previous studies have connected activation of MMP-9 with corneal thickness reduction or corneal melting.

The study authors concluded that isotretinoin results in remodeling of the corneal layers, resulting in statistical differences in surface variance and pachymetry-related parameters.

Ozyol P, Ozyol E, Yildirim FE. Remodeling of cornea with isotretinoin treatment. Eye Contact Lens. 2020;1-6.