Occurrence and mechanism of visual phosphenes in external photon beam radiation therapy and how to influence them

W. de Kruijf*, A. Timmers, J. Dekker, F. Böing-Messing, T. Rozema

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

Abstract

Background and purpose:
Two plausible mechanisms to explain the appearance of visual phosphenes are: direct activation of the photochemicals in the retina and the generation of Cherenkov radiation in the vitreous humour. In this clinical trial we investigated the occurrence of visual phosphenes in external photon beam radiation therapy.
Material and methods:
Logistic regression analysis is used to examine whether seeing light flashes and seeing steady light depended on the ambient light intensity and the dose.
Results:
In total, 465 treatments of 25 patients were analysed. The odds of seeing light flashes multiply by 0,926 as the ambient light intensity increases by 10 lux. Similarly, the odds multiply by 1,604 as the dose to the retina increases by 10 cGy. The odds of seeing steady light multiply by 1,540 as the dose to the vitreous humour increases by 10 cGy.
Conclusions:
We postulate that one should reduce the dose rate, instruct patients to keep the eyes open and increase the illuminance in the treatment room to reduce the probability of experiencing visual phosphenes. We hypothesize that melanopsin is involved in the visual phosphenes and that fatigue of patients might be correlated with the observation of visual phosphenes.

Original languageEnglish
Pages (from-to)109-113
JournalRadiotherapy and Oncology
Volume132
DOIs
Publication statusPublished - 2019

Fingerprint

Phosphenes
Photons
Vitreous Body
Logistic Models
Observation

Keywords

  • Cherenkov radiation
  • LIGHT-FLASHES
  • Light flashes
  • ORBIT
  • Photon beam radiation therapy
  • Photoreceptor proteins
  • SENSATIONS
  • SPACE
  • Visual phosphenes

Cite this

@article{22be213dd6fe405f9040cf5f546f7c0e,
title = "Occurrence and mechanism of visual phosphenes in external photon beam radiation therapy and how to influence them",
abstract = "Background and purpose:Two plausible mechanisms to explain the appearance of visual phosphenes are: direct activation of the photochemicals in the retina and the generation of Cherenkov radiation in the vitreous humour. In this clinical trial we investigated the occurrence of visual phosphenes in external photon beam radiation therapy.Material and methods: Logistic regression analysis is used to examine whether seeing light flashes and seeing steady light depended on the ambient light intensity and the dose.Results: In total, 465 treatments of 25 patients were analysed. The odds of seeing light flashes multiply by 0,926 as the ambient light intensity increases by 10 lux. Similarly, the odds multiply by 1,604 as the dose to the retina increases by 10 cGy. The odds of seeing steady light multiply by 1,540 as the dose to the vitreous humour increases by 10 cGy.Conclusions: We postulate that one should reduce the dose rate, instruct patients to keep the eyes open and increase the illuminance in the treatment room to reduce the probability of experiencing visual phosphenes. We hypothesize that melanopsin is involved in the visual phosphenes and that fatigue of patients might be correlated with the observation of visual phosphenes.",
keywords = "Cherenkov radiation, LIGHT-FLASHES, Light flashes, ORBIT, Photon beam radiation therapy, Photoreceptor proteins, SENSATIONS, SPACE, Visual phosphenes",
author = "{de Kruijf}, W. and A. Timmers and J. Dekker and F. B{\"o}ing-Messing and T. Rozema",
year = "2019",
doi = "10.1016/j.radonc.2018.11.010",
language = "English",
volume = "132",
pages = "109--113",
journal = "Radiotherapy and Oncology",
issn = "0167-8140",
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}

Occurrence and mechanism of visual phosphenes in external photon beam radiation therapy and how to influence them. / de Kruijf, W.; Timmers, A.; Dekker, J.; Böing-Messing, F.; Rozema, T.

In: Radiotherapy and Oncology, Vol. 132, 2019, p. 109-113.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Occurrence and mechanism of visual phosphenes in external photon beam radiation therapy and how to influence them

AU - de Kruijf, W.

AU - Timmers, A.

AU - Dekker, J.

AU - Böing-Messing, F.

AU - Rozema, T.

PY - 2019

Y1 - 2019

N2 - Background and purpose:Two plausible mechanisms to explain the appearance of visual phosphenes are: direct activation of the photochemicals in the retina and the generation of Cherenkov radiation in the vitreous humour. In this clinical trial we investigated the occurrence of visual phosphenes in external photon beam radiation therapy.Material and methods: Logistic regression analysis is used to examine whether seeing light flashes and seeing steady light depended on the ambient light intensity and the dose.Results: In total, 465 treatments of 25 patients were analysed. The odds of seeing light flashes multiply by 0,926 as the ambient light intensity increases by 10 lux. Similarly, the odds multiply by 1,604 as the dose to the retina increases by 10 cGy. The odds of seeing steady light multiply by 1,540 as the dose to the vitreous humour increases by 10 cGy.Conclusions: We postulate that one should reduce the dose rate, instruct patients to keep the eyes open and increase the illuminance in the treatment room to reduce the probability of experiencing visual phosphenes. We hypothesize that melanopsin is involved in the visual phosphenes and that fatigue of patients might be correlated with the observation of visual phosphenes.

AB - Background and purpose:Two plausible mechanisms to explain the appearance of visual phosphenes are: direct activation of the photochemicals in the retina and the generation of Cherenkov radiation in the vitreous humour. In this clinical trial we investigated the occurrence of visual phosphenes in external photon beam radiation therapy.Material and methods: Logistic regression analysis is used to examine whether seeing light flashes and seeing steady light depended on the ambient light intensity and the dose.Results: In total, 465 treatments of 25 patients were analysed. The odds of seeing light flashes multiply by 0,926 as the ambient light intensity increases by 10 lux. Similarly, the odds multiply by 1,604 as the dose to the retina increases by 10 cGy. The odds of seeing steady light multiply by 1,540 as the dose to the vitreous humour increases by 10 cGy.Conclusions: We postulate that one should reduce the dose rate, instruct patients to keep the eyes open and increase the illuminance in the treatment room to reduce the probability of experiencing visual phosphenes. We hypothesize that melanopsin is involved in the visual phosphenes and that fatigue of patients might be correlated with the observation of visual phosphenes.

KW - Cherenkov radiation

KW - LIGHT-FLASHES

KW - Light flashes

KW - ORBIT

KW - Photon beam radiation therapy

KW - Photoreceptor proteins

KW - SENSATIONS

KW - SPACE

KW - Visual phosphenes

U2 - 10.1016/j.radonc.2018.11.010

DO - 10.1016/j.radonc.2018.11.010

M3 - Article

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JO - Radiotherapy and Oncology

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SN - 0167-8140

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