Optic disc tilt direction determines the location of initial glaucomatous damage

Area of Science:

• Ophthalmology
• Optometry
• Glaucoma Research

Background:

• Glaucoma is a leading cause of irreversible blindness.
• Optic disc morphology, including tilt and torsion, is implicated in glaucoma pathogenesis.
• Understanding these morphological variations is crucial for early detection and management.

Purpose of the Study:

• To investigate differences in optic disc tilt and torsion between normal controls and glaucoma patients.
• To ascertain if the direction of optic disc tilt correlates with the initial location of glaucomatous visual field defects.

Main Methods:

• Analysis of glaucoma patients with superior/inferior hemifield loss (n=136) and normal controls (n=99).
• Measurement of disc ovality and torsion using retinal photographs.
• Optic disc imaging via Heidelberg Retinal Tomography (HRT) III and Cirrus spectral-domain Optical Coherence Tomography (OCT).
• Assessment of temporal and vertical disc tilt using topographic images.

Main Results:

• Disc ovality correlated with temporal disc tilt and axial length (AL) across all subjects.
• Disc torsion correlated with vertical disc tilt and AL.
• Vertical disc tilt and torsion degree differed significantly between glaucoma patients with superior and inferior hemifield defects.
• HRT-measured vertical disc tilt independently predicted the initial location of visual field defects.

Conclusions:

• Vertical disc tilt measurement offers valuable insights into superior versus inferior regional susceptibilities in glaucoma.
• This finding may aid in predicting the pattern of visual field loss in glaucoma patients.