Frequency Doubling Technology Visual Field Loss in Fabry Subjects Related to Retinal Ganglion Cell Function as...

Area of Science:

• Ophthalmology
• Genetics
• Vascular Biology

Background:

• Fabry disease is a rare genetic disorder.
• Visual field loss is a potential complication.
• Causes of visual field deficits require further investigation.

Purpose of the Study:

• To investigate potential causes of frequency doubling technology (FDT) visual field loss in Fabry disease patients.
• To compare FDT results with standard automated perimetry (SAP).
• To assess retinal function and vascular status.

Main Methods:

• Pilot observational study with two assessment visits.
• Tests included visual acuity, tonometry, OCT, FDT and SAP perimetry, ERG, and ocular blood oxygenation (OSOME).
• Results compared between visits and with a non-Fabry control group.

Main Results:

• All Fabry subjects exhibited FDT defects, unlike SAP results.
• FDT showed significantly different patterns (PSD) compared to SAP.
• Electroretinogram (ERG) revealed prolonged peak times for i-waves and B-waves.
• Ocular blood oxygenation and volume measurements indicated capillary perfusion loss and exceeded normal ranges.
• Blood volume correlated with FDT PSD in the superior optic nerve area.

Conclusions:

• Fabry subjects demonstrate FDT deficits and abnormal ERG findings.
• These abnormalities may stem from retinal dysfunction impacting retinal ganglion cells (RGCs).
• Underlying vascular alterations are suggested as the cause of retinal dysfunction.