Adhesion failures determine the pattern of choroidal neovascularization in the eye: a computer simulation study

Area of Science:

• Ophthalmology
• Cell Biology
• Biophysics

Background:

• Choroidal neovascularization (CNV) is a leading cause of adult vision loss.
• CNV involves abnormal blood vessel growth in the retina.
• Existing theories focus on growth factors or Bruch's membrane (BrM) defects.

Purpose of the Study:

• To investigate the role of adhesion properties in CNV initiation and progression.
• To model the three distinct CNV growth patterns (Type 1, 2, and 3).
• To challenge the prevailing hypotheses on CNV etiology.

Main Methods:

• Developed a three-dimensional, multi-cell simulation model of the macula.
• Simulated interactions between retinal pigment epithelium (RPE) cells, BrM, and photoreceptors.
• Varied parameters for RPE-RPE, RPE-BrM, and RPE-photoreceptor outer segment (POS) adhesion.

Main Results:

• Intact RPE adhesion (epithelial, basal to BrM, apical to POS) prevents CNV.
• Small BrM holes alone do not initiate CNV.
• Weak RPE-BrM adhesion leads to sub-RPE (Type 1) CNV.
• Reduced RPE-POS or RPE-RPE adhesion causes sub-retinal (Type 2) CNV.
• Combined adhesion defects result in mixed or progressing CNV patterns.

Conclusions:

• Adhesion defects are the primary drivers of CNV initiation and progression.
• The model successfully recapitulates observed CNV patterns based on adhesion failures.
• This suggests novel therapeutic targets focusing on restoring cellular adhesion.