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Tolerance to light of patients suffering from infectious keratitis
Author(s) -
Courrier Emilie,
Lambert Victor,
Renault Didier,
Garcin Thibaud,
Caroline Trone Marie,
Herbepin Pascal,
Moine Baptiste,
Thuret Gilles,
Gain Philippe
Publication year - 2021
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2020.0059
Subject(s) - irradiance , phototoxicity , medicine , wavelength , autofluorescence , ophthalmology , optics , keratitis , optoelectronics , materials science , chemistry , fluorescence , physics , biochemistry , in vitro
Purpose With very photophobic patients, the advantages of red or near infrared (NIR) light to develop new ophthalmology imaging devices seem obvious: no or little glare, possibility of long signal integration, no phototoxicity, and lesser autofluorescence of ocular tissues. Nevertheless, in this range, the shortest possible wavelength facilitates signal detection. Aim To determine the maximal irradiance tolerated with 6 wavelengths: 2 red, 2 far red and 1 NIR lights in order to determine the shortest wavelength well tolerated by patients, in comparison with the standard cobalt blue light of ophthalmology slit lamp. Methods Study design: interventional, monocentric, single group assignment study on 30 eyes of 30 patients with infectious keratitis after informed consent. Thanks to a customized machine from our laboratory, the photophobic eye was exposed to the 6 lights with increasing intensity. The patients switched off the light when the discomfort was too elevated. The maximal cumulative irradiance possible at 482, 650, 675, 700, 750 and 800 nm were respectively 171, 689, 759, 862, 920 and 889 mW/cm 2 . Results The maximal cumulative irradiance tolerated increased significantly with wavelength (p < 0.001). However, the difference was not significant between each increment. Thus, red at 675 nm gave a significantly higher cumulative irradiance than blue at 482 nm. Red at 700 nm did not provide significant gain; however, far red at 750 nm still provided additional gain, but not at 800 nm. The shortest wavelengths were stopped more quickly and more than 50% of patients reached the maximum irradiance delivered by the source at 750 and 800 nm. Conclusions We demonstrate that a light source at 750 and 800 nm can be used for ophthalmic imaging with good tolerance in the photophobic patient.