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Two-color pupillometry in KCNV2 retinopathy
Frederick T Collison1, Jason C Park2, Gerald A Fishman3,4
1The Pangere Center for Inherited Retinal Diseases, The Chicago Lighthouse, 1850 West Roosevelt Rd, Chicago, IL, 60608, USA.
Documenta Ophthalmologica. Advances in Ophthalmology
|March 31, 2019
Summary
Pupillary light reflex (PLR) and electroretinogram (ERG) tests reveal outer retinal dysfunction in KCNV2 retinopathy, suggesting inner retinal function is preserved. This highlights potential therapeutic targets for restoring vision.
Area of Science:
- Ophthalmology
- Neuroscience
- Genetics
Background:
- KCNV2 retinopathy, a form of cone dystrophy with supernormal rod electroretinogram (ERG), presents unique challenges in understanding retinal function.
- Investigating both receptor and post-receptor pathways is crucial for a comprehensive understanding of this condition.
Purpose of the Study:
- To evaluate receptor and post-receptor function in KCNV2 retinopathy using pupillary light reflex (PLR) and ERG.
- To differentiate between outer and inner retinal function abnormalities in patients with KCNV2 retinopathy.
Main Methods:
- Two patients with molecularly confirmed KCNV2 retinopathy underwent full-field two-color pupillometry and ERG testing.
- Pupillometry included dark- and light-adapted conditions with blue and red stimuli.
- ERG testing involved dark-adapted intensity series and standard stimuli.
Main Results:
- Dark-adapted PLRs were attenuated at low luminance but normal at high luminance for blue stimuli.
- Light-adapted PLRs were generally normal and favored blue over red stimuli, suggesting rod or S-cone mediation.
- ERG revealed decreased cone responses and absent low-luminance rod responses, with delayed b-waves at low luminance.
Conclusions:
- Pupillometry findings mirror ERG abnormalities, indicating outer retinal dysfunction in KCNV2 retinopathy.
- Normal sustained PLR suggests preserved inner retinal function.
- These findings support the potential for therapies targeting outer retinal restoration in KCNV2 retinopathy.
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