Bilateral Pattern Electroretinogram Abnormalities in Patients with Herpes Zoster Keratitis and Conjunctivitis

Area of Science:

• Ophthalmology
• Neuroscience
• Virology

Background:

• Herpes zoster ophthalmicus (HZO) is caused by varicella zoster virus (VZV) reactivation.
• VZV inflammation affects multiple ocular tissues.
• Understanding HZO's impact on retinal function is crucial.

Purpose of the Study:

• Evaluate pattern electroretinogram (PERG) changes in HZO patients.
• Assess the relationship between PERG alterations and corneal sub-basal nerve damage.
• Compare HZO patients with healthy controls.

Main Methods:

• Cross-sectional study involving 22 HZO patients and 20 healthy controls.
• PERG testing performed on HZO patients' eyes and controls' eyes.
• In vivo confocal microscopy (IVCM) used to examine corneal nerves in HZO patients.

Main Results:

• HZO patients showed altered PERG parameters (delayed N95 peak time, reduced P50/N95 amplitude) in both affected and unaffected eyes compared to controls.
• IVCM revealed decreased corneal nerve length and number in affected HZO eyes.
• No significant correlation found between corneal nerve changes and PERG alterations.

Conclusions:

• HZO impacts electrophysiological responses, with reduced N95 amplitude and prolonged P50 peak time observed even without central cornea involvement.
• Further research is needed to fully understand HZO's effects on ocular electrophysiology and the posterior segment.