Morphological study on the human developing vitreous collagen fibrils and persistent hyperplastic primary vitreous

Area of Science:

• Ophthalmology
• Biomaterials Science
• Cell Biology

Background:

• The primary vitreous is crucial for ocular development.
• Persistent hyperplastic primary vitreous (PHPV) is a congenital condition involving abnormal vitreous development.
• Understanding the ultrastructure of vitreous abnormalities is key to diagnosing and managing ocular disorders.

Purpose of the Study:

• To characterize the ultrastructural and histochemical properties of the intravitreal strand in a case of PHPV.
• To compare the fibrillar components of the PHPV intravitreal strand with normal human primary and secondary vitreous fibrils.

Main Methods:

• Electron microscopy was used for ultrastructural observation of vitreous fibrils.
• Histochemical analysis was performed to determine the composition of the intravitreal strand.
• Morphological continuity between the intravitreal strand and the optic disc was examined.

Main Results:

• Human primary and secondary vitreous fibrils exhibited similar ultrastructural characteristics.
• The intravitreal strand in PHPV contained abundant collagenous fibrils (40-50 nm diameter, 65 nm periodicity) and non-striated fibrils (10-30 nm diameter).
• Complete morphological continuity was observed between the intravitreal strand and the optic disc, with likely collagenous and glial components.

Conclusions:

• The fibrillar components of the intravitreal strand in PHPV significantly differ from those of the primary vitreous.
• These findings suggest a distinct pathological composition of the vitreous in PHPV.
• Further studies with more cases are warranted to confirm these observations and elucidate the pathogenesis of PHPV.