Normal and staphylomatous sclera of high myopia. An electron microscopic study

Area of Science:

• Ophthalmology
• Biomaterials Science
• Connective Tissue Biology

Background:

• Pathological myopia is associated with scleral ectasia.
• Understanding scleral ultrastructure is crucial for myopia research.

Purpose of the Study:

• To compare the ultrastructure of collagen fibrils in normal and myopic sclera using electron microscopy.
• To identify specific ultrastructural differences that may underlie scleral ectasia in myopia.

Main Methods:

• Electron microscopy was used to examine posterior scleral tissue.
• Samples were obtained from three normal eyes and five staphylomatous, myopic eyes.
• Detailed analysis of collagen fibril arrangement, diameter, and morphology was performed.

Main Results:

• Myopic sclera exhibited a predominantly lamellar collagen arrangement.
• A reduction in collagen fibril diameter and increased diameter dispersion were observed in myopic sclera.
• Unusual star-shaped fibrils and prevalence of uniform, fine fibril groups were noted in myopic sclera.

Conclusions:

• The observed ultramicroscopic changes in myopic sclera align with previous studies.
• These findings suggest an abnormal proteoglycan composition of the interfibrillary substance in ectatic myopic sclera.
• The ultrastructural alterations may contribute to the biomechanical properties of the myopic sclera.