Bilateral Increase of Matrix Metalloproteinase-9 Expression in Tears After the Unilateral Decrease of Corneal...

Area of Science:

• Ophthalmology
• Corneal Disease
• Tear Film Analysis

Background:

• Neurotrophic keratitis (NK) is a degenerative condition affecting cornealInnervation.
• Matrix metalloproteinase-9 (MMP-9) plays a role in corneal tissue remodeling and inflammation.
• Understanding bilateral changes in NK is crucial for comprehensive patient management.

Purpose of the Study:

• To investigate bilateral changes in tear film matrix metalloproteinase-9 (MMP-9) expression in patients with unilateral neurotrophic keratitis.
• To correlate MMP-9 levels with clinical parameters in affected and unaffected eyes.

Main Methods:

• Tear MMP-9 levels were measured using a point-of-care immunoassay.
• Included a control group and a group with unilateral neurotrophic keratitis (UDCS).
• Assessed clinical parameters: meibomian gland plugging, meibum quality, tear secretion, and corneal erosions.

Main Results:

• Tear MMP-9 levels were significantly elevated in both affected and contralateral eyes of UDCS patients compared to controls.
• Lacrimal secretion was reduced in affected eyes but preserved in contralateral eyes.
• Contralateral eye MMP-9 levels correlated with meibum quality, suggesting potential meibomian gland dysfunction.

Conclusions:

• Unilateral neurotrophic keratitis is associated with a bilateral increase in tear film MMP-9.
• Despite preserved tearing and corneal barrier in unaffected contralateral eyes, meibomian gland function may be compromised.
• This highlights the need for monitoring meibomian gland function in the contralateral eye of unilateral NK patients.