Lamina Cribrosa Microarchitecture in Monkey Early Experimental Glaucoma: Global Change

Area of Science:

• Ophthalmology
• Glaucoma Research
• Biomechanics

Background:

• Glaucoma is a leading cause of irreversible blindness.
• The lamina cribrosa (LC) is a critical structure in the optic nerve head affected by glaucoma.
• Understanding structural changes in the LC is vital for glaucoma diagnosis and treatment.

Purpose of the Study:

• To quantify differences in lamina cribrosa (LC) structural parameters between experimental glaucoma (EG) and control eyes in a monkey model.
• Specifically, to analyze changes in beam diameter (BD), pore diameter (PD), connective tissue volume fraction (CTVF), connective tissue volume (CTV), and LC volume (LV).

Main Methods:

• Three-dimensional reconstruction and LC beam segmentation of optic nerve heads from EG and normal monkeys.
• Calculation of full-thickness and layer-specific averages for BD, PD, CTVF, CTV, and LV.
• Statistical analysis using linear mixed-effects (LME) modeling to assess EG effects and intereye differences.

Main Results:

• Monkey eyes with early EG showed significantly larger mean PD (+12.8%), CTV (+26.5%), and LV (+40%) compared to control eyes.
• EG effects on PD and CTVF varied significantly by layer.
• While PD consistently expanded, EG eye-specific changes in BD and CTVF were variable.

Conclusions:

• Early experimental glaucoma in monkeys leads to increases in pore diameter, connective tissue volume, and lamina cribrosa volume.
• Structural changes in the lamina cribrosa, particularly beam diameter and connective tissue volume fraction, exhibit considerable variability between individual affected eyes.