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Record W2996366853 · doi:10.1111/j.1755-3768.2019.5388

Reduced pattern electroretinogram signal in affected patients with Leber Hereditary Optic Neuropathy

2019· article· en· W2996366853 on OpenAlexaff
Melanie Lalonde, Ange‐Lynca Kantungane, Alfredo A. Sadun, Stuart G. Coupland, Rustum Karanjia

Bibliographic record

VenueActa Ophthalmologica · 2019
Typearticle
Languageen
FieldBiochemistry, Genetics and Molecular Biology
TopicRetinal Development and Disorders
Canadian institutionsOttawa HospitalUniversity of Ottawa
Fundersnot available
KeywordsOphthalmologyRetinalPhotopic visionElectroretinographyOptic neuropathyMedicineVisual fieldRetinaOptic nerveNerve fiber layerLeber's hereditary optic neuropathyRetinal ganglion cellGanglionGlaucomaAudiologyNeuroscienceBiologyAnatomy

Abstract

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Abstract Purpose The pattern electroretinogram (PERG) signal has been reported to be a sensitive tool for the detection of retinal ganglion cell (RGC) dysfunction in both animal models and patients suffering from optic neuropathies. This study investigated whether functional PERG can detect different levels of RGC dysfunction in both carriers and affected patients with Leber Hereditary Optic Neuropathy (LHON). Methods PERG signals were recorded using both checkerboard (0.8° check size, 2 reversals/sec) and bars (0.5 cycles/deg) stimuli with mean luminance of 300 cd/m2 and 100% contrast. PERG signals were measured against functional full field Photopic Negative Response (PhNR) recordings (red flashes at 5 cd s/m 2 stimulus intensity on blue rod saturating background) and subjective measures of retinal sensitivity (mean deviation [MD] via 30‐2 automated visual fields) and structural metrics (both ganglion cell complex [GCC] and retinal nerve fiber layer [RNFL] thickness from optical coherence tomography [OCT] scans). Results PERG P50 amplitudes were similar across controls, carriers, and LHON affected patients. P50 implicit times were significantly reduced in LHON affected patients (CHECKS: 45.8 ± 1.1 ms; BARS: 43.5 ± 0.8 ms; n = 32) compared to controls (CHECKS: 49.3 ± 0.5 ms; BARS: 48.1 ± 0.4 ms; n = 72). N95 amplitudes elicited by the checkerboard stimulus were significantly reduced and implicit times significantly increased in LHON affected patients (−3.4 ± 0.4 µV; 93.6 ± 2.2 ms; n = 32) compared to controls (−5.9 ± 0.5 µV; 85.3 ± 0.8 ms; n = 72). No differences were seen in PERG signals between control or LHON affected patients and carriers. Although PERG parameters were significantly different in LHON affected patients, the measurements were not correlated with PhNR signals, MD and RNFL thickness in all four quadrants around the optic disc. On the other hand, PhNR amplitudes, which were significantly reduced in LHON affected (−16.3 ± 3.4 µV; n = 32) and in carriers (−21.8 ± 3.0 µV; n = 30) compared to controls (−34.2 ± 2.5 µV; n = 28), were correlated with MD (r = −0.611, p < 0.0005; n = 28), average GCC (r = −0.618, p < 0.0001; n = 32) and average RNFL thickness (r = −0.553, p < 0.001; n = 31) in affected patients. Conclusions Significant differences in PERG recordings were measured between control and LHON affected patients. However, no significant differences were seen in carriers and PERG metrics were not correlated with functional PhNR parameters and other subjective and objective measurements tested. Our results suggest that PERG may not be as sensitive as PhNR to discriminate different levels of RGC dysfunction between LHON affected patients and carriers.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.098
Threshold uncertainty score0.725

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.005
GPT teacher head0.209
Teacher spread0.204 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one teacher head, not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

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Citations0
Published2019
Admission routes1
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