Changes in Retinal Nerve Fiber and Ganglion Cell Layers After Chemical Injury: A Prospective Study

Area of Science:

• Ophthalmology
• Ocular Trauma
• Retinal Imaging

Background:

• Chemical eye burns are ophthalmic emergencies with potential for permanent vision loss.
• Evaluating posterior segment structural changes after chemical burns is crucial for understanding long-term effects.
• Previous studies have not fully elucidated the impact of chemical burns on retinal layers.

Purpose of the Study:

• To assess structural changes in the posterior segment, specifically retinal nerve fiber layer (RNFL) and ganglion cell complex (GCL++) thickness, following chemical eye burns.
• To determine the correlation between burn severity (Dua grade) and posterior segment structural alterations.
• To identify predictors of RNFL thinning in patients with chemical eye burns.

Main Methods:

• Optical coherence tomography (OCT) was used to measure RNFL and GCL++ thickness in 64 eyes of 54 chemical burn patients and 87 healthy control eyes.
• Measurements were taken during the acute phase and at 3- and 6-month follow-ups.
• Logistic regression analysis was employed to identify predictors of RNFL thinning, with Dua grade as a key factor.

Main Results:

• No significant differences in overall RNFL or GCL++ thickness were found between chemical burn patients and controls.
• Severe chemical burns (Dua grade ≥ 3) were associated with significant RNFL thinning, particularly in the nasal quadrant (adjusted p = 0.035).
• Higher Dua grade was identified as an independent predictor of RNFL thinning (OR: 4.816, p = 0.037).

Conclusions:

• While overall RNFL and GCL++ thickness are not significantly affected, severe chemical burns lead to localized RNFL thinning in the nasal quadrant.
• Burn severity, as indicated by the Dua grade, is a significant predictor of RNFL thinning.
• Further longitudinal studies with larger cohorts are warranted to confirm these findings and explore long-term visual outcomes.