Anterior corneal striae (ACS) is known to be associated with low intraocular pressure (IOP), however, the medical community has known little about the risk factors of striae.* In a study in the Journal of Glaucoma, researchers aimed to find the differences in eyes with striae compared to eyes without striae in patients who had glaucoma surgery.

What the Researchers Did

Researchers analyzed adults with and without ACS after eight or more weeks after glaucoma surgery and who had an IOP of  ≤10 mmHg. They used optical coherence tomography and optical biometry to evaluate their eyes.

They measured:

• corneal hysteresis (CH), which is the difference in pressure between corneal indentation and reformation in response to air jet pressure, by using ocular response analyzer.  
• hypotony maculopathy (HM), which presents as optic disc swelling, vascular tortuosity attributed to hypotony, or clinical presence of chorioretinal folds, and which was confirmed on OCT.

What They Found

After researchers analyzed 116 eyes, including 76 people with ACS and 40 without, they found that individuals with ACS had a lower IOP compared to those without ACS.

Additionally, the study revealed:

• A 1 mmHg increase in corneal hysteresis had increased the odds of having ACS.
• An increase of one diopter in the flattest pre-surgical and post-surgical corneal power increased ACS odds by almost twice as much.
• Astigmatism increased in eyes with ACS by 1.11 diopters.
• The odds of having ACS increased with every one-minute increase in mitomycin-C duration and decreased with use of topical glaucoma medication.
• Hypotony maculopathy occurred in 19% of people with ACS.
• A higher post-surgical corneal hysteresis increased the odds of having hypotony maculopathy.
• “Hypotony maculopathy predicted a decrease in axial length by 0.41 mm, independent of IOP.”

What it Means

In essence, the researchers found that corneal striae is associated with features such as steeper cornea, astigmatism, and higher corneal hysteresis, in which the eye looks more cupped. Striae is also associated with low intraocular pressure (IOP).

They believe there is a relationship between striae, the shape of the cornea, and the cornea’s role in resisting deformations at a lower IOP. 

Finally, corneal hysteresis, hypotony maculopathy, and axial length shortening were associated with striae apart from IOP status.

*Birnbaum F.A., Mirzania D, Swaminathan S.S., Davis A.R., Perez V.L., Herndon L.W.. (2021, May 31). Risk Factors for Corneal Striae in Eyes after Glaucoma Surgery. Physician’s Weekly. https://www.physiciansweekly.com/risk-factors-for-corneal-striae-in-eyes-after-glaucoma-surgery