Biometric parameters in different stages of primary angle closure using low-coherence interferometry.

Area of Science:

• Ophthalmology
• Biometry
• Anatomical studies

Background:

• Primary angle closure (PAC) is a significant cause of vision loss.
• Understanding ocular biometric changes is crucial for diagnosing and managing PAC.
• Previous studies have explored various parameters, but a comprehensive comparison across PAC stages using low-coherence interferometry is needed.

Purpose of the Study:

• To compare ocular biometric parameters using low-coherence interferometry in siblings with varying degrees of primary angle closure (PAC).
• To identify key biometric indicators that differentiate between normal eyes, PAC suspects, PAC, and PAC glaucoma.

Main Methods:

• A cross-sectional study involving 170 eyes from 86 siblings across 47 families.
• Low-coherence interferometry (LenStar 900) was used to measure central corneal thickness, anterior chamber depth (ACD), aqueous depth (AD), lens thickness (LT), vitreous depth, and axial length (AL).
• Statistical analyses included regression coefficients to assess trends and receiver operating characteristic (ROC) curves to evaluate diagnostic power.

Main Results:

• Significant stepwise changes in all measured biometric parameters were observed across normal eyes, PAC suspects, PAC, and PAC glaucoma.
• A decrease in central corneal thickness, ACD, AD, vitreous depth, and AL, along with an increase in LT and LT/AL, was noted with increasing PAC severity.
• ACD (cutoff 3.11 mm) and AD (cutoff 2.57 mm) demonstrated the highest diagnostic power for detecting angle closure, with excellent sensitivity and specificity.

Conclusions:

• Low-coherence interferometry effectively quantifies significant and stepwise biometric changes associated with increasing degrees of primary angle closure.
• Biometric parameters correlate strongly with the current anatomical classification of angle closure, offering valuable diagnostic insights.