Detection of Primary Angle Closure Glaucoma Progression by Optical Coherence Tomography

Area of Science:

• Ophthalmology
• Medical Imaging
• Glaucoma Research

Background:

• Glaucoma diagnosis and progression monitoring are critical for preserving vision.
• Spectral-domain optical coherence tomography (SD-OCT) offers high-resolution imaging of retinal structures.
• Differentiating progression patterns between primary angle-closure glaucoma (PACG) and primary open-angle glaucoma (POAG) is essential.

Purpose of the Study:

• To compare the efficacy of SD-OCT in assessing retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) changes for detecting progression in PACG versus POAG.
• To evaluate the diagnostic accuracy of RNFL and GCC thinning in identifying glaucoma progression in both subtypes.

Main Methods:

• A prospective study followed 131 subjects with PACG and POAG over 72 months, with assessments every 6 months.
• Visual field (VF) progression was analyzed using Guided Progression Analysis (GPA).
• Structural changes in RNFL and GCC were measured using SD-OCT, and progression was compared between PACG and POAG using Kaplan-Meier and log-rank tests.

Main Results:

• Glaucoma progression was detected in 57% of POAG eyes and 59% of PACG eyes.
• The rate of RNFL and GCC thinning was significantly higher in PACG compared to POAG.
• In PACG, GCC thinning correlated better with visual function deterioration and predicted earlier functional loss than RNFL thinning. In POAG, both RNFL and GCC thinning correlated with functional loss.

Conclusions:

• SD-OCT is vital for monitoring PACG progression.
• Ganglion cell complex (GCC) thinning is a more sensitive indicator of functional vision loss in PACG than retinal nerve fiber layer (RNFL) thinning.
• Understanding these differences aids in tailored glaucoma management strategies.