Correlation of pattern electroretinogram with optic disc cup shape in ocular hypertension

Area of Science:

• Ophthalmology
• Neuroscience
• Medical Imaging

Background:

• Ocular hypertension (OHT) is a risk factor for glaucoma, characterized by elevated intraocular pressure.
• Early detection of optic nerve head damage in OHT is crucial for preventing vision loss.
• Pattern electroretinogram (PERG) assesses inner retinal function, while confocal scanning laser ophthalmoscopy (CSLO) evaluates optic disc structure.

Purpose of the Study:

• To investigate the relationship between PERG amplitudes and optic disc structural parameters obtained via CSLO in patients with OHT.
• To determine if functional deficits (PERG) correlate with structural changes in the optic disc in OHT.
• To assess the diagnostic potential of combining PERG and CSLO for early optic nerve head damage detection in OHT.

Main Methods:

• Thirty-four OHT patients with normal visual fields underwent PERG and CSLO optic disc analysis.
• PERG amplitudes were measured using sinusoidal gratings at various spatial frequencies.
• Heidelberg Retina Tomograph (HRT) provided morphometric optic disc parameters, including cup shape measure.

Main Results:

• A significant negative correlation was found between PERG amplitudes and inferotemporal sector cup shape measures in OHT patients (r = -0.43, P < 0.01).
• OHT patients with abnormal PERGs showed significantly worse cup shape measures, closer to those of early open-angle glaucoma (EOAG) patients.
• Cup shape measure demonstrated high specificity (100%) but low sensitivity (20%) for predicting PERG abnormalities.

Conclusions:

• A significant, albeit weak, correlation exists between PERG function and optic disc cup shape in OHT.
• These findings suggest parallel involvement of retinal function and optic disc morphology in OHT.
• Combined PERG and CSLO analysis holds potential for diagnosing early optic nerve head damage in OHT patients.