Electronegative Electroretinograms in the United Arab Emirates
Abrar K Alsalamah1, Arif O Khan2,3
1Vitreoretinal and Uveitis Divisions, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia.
Middle East African Journal of Ophthalmology
|September 3, 2020
Summary
Electronegative electroretinograms (ERGs) in Emirati patients with inherited retinal disease were most often linked to congenital stationary night blindness (CSNB) and X-linked retinoschisis (XLRS). This study identified causes of this specific ERG pattern in the region.
Area of Science:
- Ophthalmology
- Genetics
- Neuroscience
Background:
- An electronegative electroretinogram (ERG), characterized by a b:a wave ratio ≤1, signifies inner retinal dysfunction.
- Causes of electronegative ERGs vary globally, with limited data from the Arabian Gulf regarding inherited retinal diseases.
Purpose of the Study:
- To determine the frequency and causes of electronegative ERGs in Emirati patients with inherited retinal disease.
- To describe the spectrum of inherited retinal diseases associated with electronegative ERGs in this specific population.
Main Methods:
- Retrospective review of full-field ERGs from Emirati patients seen between January 2017 and December 2019.
- Inclusion criteria: Emirati patients with an electronegative ERG in at least one eye.
Main Results:
- Nine out of 137 patients (6.6%) exhibited an electronegative ERG.
- Common diagnoses included congenital stationary night blindness (CSNB) and X-linked retinoschisis (XLRS).
- Other diagnoses observed were cone-rod dystrophy and enhanced S-cone syndrome (ESCS).
Conclusions:
- Recessive CSNB and XLRS are the most frequent inherited retinal diseases associated with electronegative ERGs in this Emirati cohort.
- An electronegative ERG was also observed in a case of NRL-related ESCS.
