Structure and Function of Lens Suture Examined by 2-photon Fluorescence Microscopic Imaging

Area of Science:

• Ophthalmology
• Cell Biology
• Biophysics

Background:

• Lens sutures are hypothesized to facilitate microcirculation for maintaining transparency.
• Understanding lens suture morphology is crucial for diagnosing cataracts.

Purpose of the Study:

• To investigate mouse eye lens structures and functions, particularly sutures, using 2-photon fluorescence microscopy (2PFM).
• To compare wildtype (WT) and KLPH-knockout (KLPH-KO) lenses to identify morphological differences associated with suture cataracts.

Main Methods:

• In vivo 2-photon fluorescence microscopy (2PFM) of WT and KLPH-KO mouse eye lenses.
• 3D imaging and quantitative analysis of lens suture patterns using similarity indices (SSIM).
• Observation and characterization of lens voids and vacuoles.

Main Results:

• WT lenses showed typical 'Y' and 'double Y' suture patterns; KLPH-KO lenses exhibited diverse, misaligned patterns including 'star' shapes.
• KLPH-KO lenses displayed significantly increased suture pattern randomization (p<0.05).
• Both lens types had voids around sutures and enlarged vacuoles; KLPH-KO lenses showed pathological features like irregular central voids with amorphous structures.

Conclusions:

• 2PFM provides new morphological markers for suture cataract and lens fiber pathology.
• Lens sutures are stable, impermeable structures, while peripheral fiber extracellular spaces facilitate microcirculation.
• KLPH-KO lenses exhibit distinct suture abnormalities and pathological features relevant to cataract development.