Imaging the Macular Pigment

Berendschot, Tos T. J. M.

doi:10.1007/978-3-540-85540-8_6

Cited by 5 publications

(4 citation statements)

References 133 publications

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“…In many cases algorithms to artificially increase the contrast of an image are used, especially when qualitative characterization of a fundal structure is the objective. There are, however, cases where the actual contrast of the fundus is of interest, with most important example that of macular pigment optical density (MPOD) measurements using the reflectometry method, where MPOD is calculated using the intensities of two fundus images, one at short and one at medium wavelength [26][27][28][29][30]. In this case, scattering would decrease contrast in the two images differently, leading to an underestimation of MPOD.…”

Section: Discussionmentioning

confidence: 99%

Intraocular scattering compensation in retinal imaging

Christaras¹,

Ginis²,

Pennos³

et al. 2016

Biomed. Opt. Express

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Intraocular scattering affects fundus imaging in a similar way that affects vision; it causes a decrease in contrast which depends on both the intrinsic scattering of the eye but also on the dynamic range of the image. Consequently, in cases where the absolute intensity in the fundus image is important, scattering can lead to a wrong estimation. In this paper, a setup capable of acquiring fundus images and estimating objectively intraocular scattering was built, and the acquired images were then used for scattering compensation in fundus imaging. The method consists of two parts: first, reconstruct the individual's wide-angle Point Spread Function (PSF) at a specific wavelength to be used within an enhancement algorithm on an acquired fundus image to compensate for scattering. As a proof of concept, a single pass measurement with a scatter filter was carried out first and the complete algorithm of the PSF reconstruction and the scattering compensation was applied. The advantage of the single pass test is that one can compare the reconstructed image with the original one and see the validity, thus testing the efficiency of the method. Following the test, the algorithm was applied in actual fundus images in human eyes and the effect on the contrast of the image before and after the compensation was compared. The comparison showed that depending on the wavelength, contrast can be reduced by 8.6% under certain conditions. of the human rod photoreceptor mosaic using a confocal adaptive optics scanning ophthalmoscope," Biomed. Opt.

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Section: Discussionmentioning

confidence: 99%

Intraocular scattering compensation in retinal imaging

Christaras¹,

Ginis²,

Pennos³

et al. 2016

Biomed. Opt. Express

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“…Līdzīgi ka citas metodēs arī šeit tiek izmanota gaisma ar diviem viļņa garumiem-vienu, kuru absorbē makulas pigments un otru, kurš netiek absorbēts. Iekārtas, ar kurām var noteikt MPOB, izmantojot šo metodi, ir skenējošais lāzera oftalmoskps un fundus kamera (Berendschot 2010). Mūsdienās acs aizmugurējās daļas atstarošanas metodei ir vairākas modifikācijas, piemēram, gaismas spektra iegūšana no tīklenes centralās daļas un periferija un tā analizēšana.…”

Section: Makulas Pigmenta Optiskā Blīvuma Noteikšanas Metodesunclassified

“…Ramana spektroskopijas darbības pamatā ir Ramana izkliedes princips. Iekārtai tiek izmantots argona lāzers, kura stars tiek novirzīts uz centrālo bedrīti, līdz ar to mērījums tiek veikts tikai makulas centrālajā daļā (Berendschot 2010).…”

Section: Makulas Pigmenta Optiskā Blīvuma Noteikšanas Metodesunclassified

Cilvēka fizioloģijas un uztveres aktuālie pētījumi 2020. gadā : rakstu krājums

2020

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“…19,20 In the recent years, several in-vivo methods for the measurement of the optical density of the MP have been developed, classified in two categories: the optical, or objective, methods and the psychophysical, or subjective, ones. From the optical methods, fundus reflectance 21,22 and fundus autofluorescence 23 are the most commonly used, with good repeatability and coherent results. Among the psychophysical methods, heterochromatic flicker photometry 24,25 is the most commonly used, with several commercial devices available.…”

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confidence: 99%

Effect of intraocular scattering in macular pigment optical density measurements

et al. 2018

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Abstract. Fundus reflectometry is a common in-vivo, noninvasive method to estimate the macular pigment optical density (MPOD). The measured density, however, can be affected by the individual's intraocular scattering. Scattering causes a reduction in the contrast of the fundus image, which in turn leads to an underestimation of the measured density. Intraocular scattering was measured optically in a group of seven young, healthy subjects using the method of optical integration and was subsequently used to correctly estimate the MPOD from fundus images. It was shown that when scattering is not considered, the measured optical density using fundus reflectometry can be underestimated by as high as 16% for our group of subjects. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

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Imaging the Macular Pigment

Cited by 5 publications

References 133 publications

Intraocular scattering compensation in retinal imaging

Intraocular scattering compensation in retinal imaging

Cilvēka fizioloģijas un uztveres aktuālie pētījumi 2020. gadā : rakstu krājums

Effect of intraocular scattering in macular pigment optical density measurements

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