GCIPL color coding on OCT predicts glaucoma conversion in normal-tension glaucoma suspects, including a high myopia...

Area of Science:

• Ophthalmology
• Medical Imaging
• Glaucoma Research

Background:

• Normal-tension glaucoma (NTG) suspects require accurate risk stratification for progression.
• Assessing glaucoma conversion risk, particularly in highly myopic eyes, presents diagnostic challenges.
• Optical coherence tomography (OCT) provides quantitative structural measurements relevant to glaucoma.

Purpose of the Study:

• To evaluate the predictive value of OCT-derived color coding of retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL) thicknesses for glaucoma conversion.
• To assess the performance of this color-coding system in highly myopic eyes.
• To determine the clinical utility of GCIPL color coding for risk stratification in NTG suspects.

Main Methods:

• Retrospective analysis of 307 eyes from NTG suspects with baseline spectral-domain OCT.
• RNFL and GCIPL thicknesses were categorized using device-generated color codes (green: normal, yellow: borderline, red: abnormal).
• Glaucoma conversion was defined by reproducible visual field defects over a mean follow-up of 76 months.

Main Results:

• Inferotemporal GCIPL thickness demonstrated the strongest predictive capacity (AUC=0.68), significantly improved in highly myopic eyes (AUC=0.85).
• Red color coding in the inferotemporal sector correlated with increased conversion risk (HR 2.473, p=0.050).
• Green coding in GCIPL sectors showed high negative predictive values (85.0% overall, 90.2% in myopic subgroup), indicating disease stability.

Conclusions:

• OCT-derived GCIPL color coding is a practical tool for identifying early glaucoma stability.
• This method aids in stratifying the risk of glaucoma progression, even in high myopia.
• Color coding offers an accessible approach to risk assessment in clinical practice.