CORRELATIONS between Functional and Structural Tests Measured by Spectral Domain Optical Coherence Tomography in...

Area of Science:

• Ophthalmology
• Glaucoma Research
• Optical Coherence Tomography

Background:

• Severe glaucoma significantly impacts visual function, affecting visual acuity and visual fields.
• Understanding the structural correlates of visual impairment is crucial for managing glaucoma progression.

Purpose of the Study:

• To investigate the relationship between spectral domain optical coherence tomography (OCT) parameters and visual function in severe glaucoma.
• To assess correlations between retinal nerve fiber layer (RNFL) thickness, ganglion cell-internal plexiform layer (GC-IPL) thickness, optic nerve head parameters, and visual acuity/visual field metrics.

Main Methods:

• Patients with severe glaucoma underwent comprehensive ophthalmic examinations, including visual acuity and visual field (VF) testing (30-2 SITA standard).
• Spectral domain OCT (Cirrus EDI-OCT) was utilized for peripapillary RNFL and GC-IPL thickness measurements.
• Optic nerve head parameters (cup-to-disc ratio, rim area, cup volume) were quantified using spectral domain OCT.

Main Results:

• Statistically significant positive correlations were observed between best-corrected visual acuity (BCVA) and various GC-IPL thicknesses (mean, superior, inferonasal, superonasal, superotemporal) and rim area.
• A positive correlation was found between mean deviation (MD) and inferotemporal GC-IPL thickness.
• Negative correlations were noted between BCVA and mean cup-to-disc ratio, vertical cup-to-disc ratio, and cup volume.

Conclusions:

• Ganglion cell-internal plexiform layer (GC-IPL) thickness and optic nerve head parameters are significantly associated with visual acuity in severe glaucoma.
• These OCT-derived structural metrics provide valuable insights into the functional deficits experienced by patients with advanced glaucoma.