Evidence map›Paper›PMID 40792665›Full record

ArticleActa ophthalmologica2026

Repeatability of retinal vessel flicker responses in healthy individuals.

Angelos Kalitzeos, Robert J Summers, Rebekka Heitmar

Abstract read
In one paragraph

Article in Acta ophthalmologica, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Review
  2. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors.

Angelos KalitzeosUCL Institute of Ophthalmology, University College London, London, UK.ORCID https://orcid.org/0000-0001-8345-0557
Robert J SummersIndependent Researcher, Derby, UK.ORCID https://orcid.org/0000-0003-4857-7354
Rebekka HeitmarUniversity of Huddersfield, School of Applied Sciences, Centre for Vision across the Life Span (CVLS), Huddersfield, UK.ORCID https://orcid.org/0000-0002-7657-1788

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeTo determine the repeatability of retinal blood vessel parameters (from proprietary software and the raw vessel data) measured in vivo in healthy individuals at rest, during and post flicker light (FL) provocation using a standardised protocol.

methodsWe recorded the diameters of one retinal artery and one vein in each of 33 healthy adult volunteers at rest, during and post FL provocation on two occasions using the Retinal Vessel Analyser (RVA). Repeat visits were scheduled at three different timepoints: (1) within 30 mins on the same day, (2) within a fortnight and (3) within a month (n = 11, each). All participants underwent intraocular and systemic blood pressure assessment to ensure these were comparable between visits.

resultsRetinal vessel parameters at rest, during and post FL provocation were comparable between all pairs of visits for all three groups. Repeatability between visits was assessed using Bland-Altman Analyses and Intraclass Correlation Coefficients (ICCs). Maximum dilation for arteries and veins and maximum constriction for arteries due to FL provocation computed from raw dilation data showed better repeatability than that generated by the RVA software. Time to reach maximum dilation in arteries and veins and maximum constriction in arteries was on average comparable but least repeatable between visits.

conclusionsRetinal vessel parameters computed from the raw RVA data may be superior in quality to the output from the proprietary software because the latter uses fixed narrow time-windows to determine the parameters. Variance within healthy controls, pathology groups and repeatability parameters alongside systemic haemodynamic parameters should be considered when utilising dynamic retinal vascular parameters as study endpoints.

Indexed as

Retinal ArteryRetinal VeinRetinal VesselsVasodilationAdultBlood PressureFemaleHealthy VolunteersHumansIntraocular PressureMaleMiddle AgedPhotic StimulationReproducibility of ResultsYoung Adultflicker provocationneurovascular couplingrepeatabilityretinal vessel analyser

Identifiers

PMID40792665
PMCPMC12888953

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.