Optic disc swelling in acute primary angle closure: Associated factors and longitudinal OCT changes

Area of Science:

• Ophthalmology
• Glaucoma Research
• Retinal Imaging

Background:

• Acute primary angle-closure glaucoma (AACG) can cause optic disc swelling (ODS).
• Understanding factors associated with ODS and its long-term effects on retinal structure is crucial for patient management.
• Optical coherence tomography (OCT) allows detailed analysis of retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL) thickness.

Purpose of the Study:

• To identify clinical factors associated with ODS in AACG.
• To evaluate longitudinal structural changes in RNFL and GCIPL in ODS eyes post-treatment using OCT.
• To compare thinning rates between eyes with and without ODS.

Main Methods:

• Retrospective study of 102 AACG eyes treated with laser iridotomy (LI) and followed for at least two years.
• Classification of eyes into ODS and control groups based on optic disc appearance and OCT findings.
• Multivariate logistic regression for factor analysis; OCT measurements of RNFL and GCIPL at six time points; calculation and comparison of short-term and long-term thinning rates.

Main Results:

• ODS was present in 42 eyes, associated with larger pupil diameter (OR=15.23) and longer symptom duration (OR=2.03).
• ODS eyes showed initial RNFL thickening followed by sustained thinning, while GCIPL thickness declined continuously.
• Long-term RNFL thinning (6 months-2 years) was significantly greater in ODS eyes (-2.86 μm/year) vs. controls (-0.77 μm/year) (P=0.005); GCIPL thinning was also greater (P=0.006).

Conclusions:

• ODS in AACG is associated with delayed treatment and larger pupils, suggesting increased ischemic stress.
• Despite IOP control, ODS eyes experience significant, sustained structural loss in RNFL and GCIPL.
• Early intervention and tailored follow-up strategies are essential for managing AACG with ODS to mitigate structural damage.