Early Biomechanical Alterations in Granular Corneal Dystrophy Type 2 From p.Ala546Asp Mutation Carriers

Area of Science:

• Ophthalmology
• Genetics
• Biomechanical Engineering

Background:

• Granular corneal dystrophy type 2 (GCD2) is a genetic condition affecting the cornea.
• The p.Ala546Asp mutation is associated with GCD2.
• Understanding corneal biomechanical changes is crucial for early diagnosis and management.

Purpose of the Study:

• To describe corneal biomechanical alterations in individuals with the p.Ala546Asp mutation.
• To compare biomechanics between mutation carriers with and without visible corneal deposits.
• To explore the relevance of biomechanical assessment for early characterization of GCD2.

Main Methods:

• A case series study involving a Mexican mestizo family with confirmed GCD2.
• Classification of participants into three groups: mutation carriers with deposits, mutation carriers without deposits, and healthy controls.
• Evaluation of corneal biomechanics using the Corvis ST system, measuring parameters like corneal biomechanical index (CBI) and stiffness parameter at first applanation (SP-A1).

Main Results:

• Mutation carriers exhibited significantly higher CBI and lower SP-A1 compared to controls, indicating altered corneal biomechanics.
• No significant biomechanical differences were observed between mutation carriers with and without visible deposits.
• These findings suggest biomechanical changes precede the formation of clinical corneal deposits.

Conclusions:

• The p.Ala546Asp mutation is linked to early corneal biomechanical instability, irrespective of visible deposits.
• Biomechanical assessment may help identify subclinical corneal changes in GCD2.
• This study enhances understanding of biomechanical variability in GCD2 mutation carriers.