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Consequences of an Increase in the Ocular Perfusion Pressure on the Pulsatile Ocular Blood Flow

2004· article· en· W2024762963 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.
fundA Canadian funder is recorded on the work.

Bibliographic record

VenueOptometry and Vision Science · 2004
Typearticle
Languageen
FieldMedicine
TopicGlaucoma and retinal disorders
Canadian institutionsUniversité de MontréalNatural Sciences and Engineering Research Council of Canada
FundersNatural Sciences and Engineering Research Council of Canada
KeywordsPulsatile flowChoroidMedicineBlood flowExertionBlood pressurePerfusionHeart rateIntraocular pressureHemodynamicsMicrocirculationRetinaOphthalmologyInternal medicineCardiologyBiology

Abstract

fetched live from OpenAlex

PURPOSE: In previous studies we have demonstrated that physical exertion constricted the major retinal arteries, increased the redness of the optic nerve head, and attenuated scotopic white flash oscillatory potentials. These anatomic and functional changes in the human retina suggested that blood flow to the innermost retinal layers was modified in some way to cause these changes. The objective of this study was to determine whether physical exertion also affected blood flow in the choroid, the exclusive source of blood to the outermost layers of the retina. METHODS: Eighteen healthy adults volunteered for this study. An OBF Tonograph system (OBF Laboratories UK Ltd., Malmesbury, Wiltshire, U.K.) was used to derive the pulsatile ocular blood flow, which reflects the pulsatile component of blood flow in the choroid, at rest and 20 minutes after biking at a heart rate of 140 beats/min. RESULTS: At the systemic level, biking increased the blood pressure and the heart rate. At the ocular level, the duration of the systolic and diastolic phases of the intraocular pulse was shortened, and the pulse amplitude and volume were reduced. Despite the attenuation of the intraocular pulse parameters, the pulsatile ocular blood flow increased by some 18% after exercise largely because of the much larger increase in heart rate. The ocular perfusion pressure increased, whereas the intraocular pressure decreased. CONCLUSIONS: Physical exertion in the form of aerobic exercise increased the pulsatile component of blood flow in the choroid. Because the choroid is the sole blood supply to the outer retina, it was concluded that the degree of perfusion of the photoreceptors necessary for vision is increased by physical exertion. This increased choroidal blood flow is presumably to sustain vision as blood is directed to the large muscle groups involved in the physical activity.

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.

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)0.002
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: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.657
Threshold uncertainty score0.333

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0020.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.001
Science and technology studies0.0000.001
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 head0.010
GPT teacher head0.351
Teacher spread0.342 · 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