Limbal stem cell deficiency (LSCD) that develops after glaucoma surgery may have unique characteristics compared with LSCD caused by other factors such as chemical injury or ocular inflammatory disease, a study in Cornea reports.

A research team found classic features of LSCD induced by glaucoma surgery included sectoral replacement of corneal epithelial cells by conjunctival epithelial cells but without significant corneal neovascularization or pannus. On the other hand, LSCD caused by a chemical injury or ocular inflammatory disease presented with diffuse limbal involvement and corneal neovascularization.

The study enrolled 41 patients (51 eyes) with LSCD associated with glaucoma who visited the Stein Eye Institute between 2009 and 2018. Patients who underwent trabeculectomy and/or aqueous shunt surgery were included.

The study found a strong link between the site of the glaucoma surgery and the location of LSCD. Additionally, the researchers observed a trend of increased LSCD severity in eyes that had two or more glaucoma surgeries compared with those who underwent a single procedure, although the difference was not significant.

Also of note: the use of topical glaucoma medications appeared to be linked with LSCD severity, while the impact of antimetabolites didn’t seem to be a factor. The researchers reported the location of glaucoma drainage surgery was correlated with the location of LSCD.

“In the case of glaucoma, patients often require subsequent surgical revisions

to achieve adequate control of intraocular pressure,” the researchers wrote in their paper. “The current study reveals a trend toward more severe stages of LSCD in patients with multiple surgeries, suggesting that repeated glaucoma surgery predisposes to increased severity of LSCD, although a larger study is needed to confirm this observation.”

Measures to reduce injury to the limbus should be considered to reduce the risk of LSCD, the study noted.

Sun Y, Yung M, Huang L, et al. Limbal stem cell deficiency after glaucoma surgery. Cornea. January 17, 2020. [Epub ahead of print].