A comparative study on ocular damage induced by 1319nm laser radiation

Chen, Hongxia; Yang, Zaifu; Wang, Jiarui; Chen, Peng; Huan-wen, Qian

doi:10.1002/lsm.21052

Cited by 11 publications

(11 citation statements)

References 27 publications

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“…27 The waist radius and the divergence of the higher order modes are M times larger than that of the TEM 00 mode. Consequently, the beam diameter of the higher order mode beam will always be M times that of the TEM 00 mode beam in any cross section.…”

Section: Methods 21 Embedded Gaussian Model and Abcd Lawmentioning

confidence: 99%

“…In above equations, is the laser wavelength, z 0 is the Rayleigh length, w 0 is the waist radius of the TEM 00 mode (corresponding to the position where the local irradiance is 1=e 2 of the central maximum level 27 ), 0 is the divergence of the TEM 00 mode, W pl and pl represent the waist radius and the divergence of higher order mode beam, respectively. 27 The waist radius and the divergence of the higher order modes are M times larger than that of the TEM 00 mode.…”

Section: Methods 21 Embedded Gaussian Model and Abcd Lawmentioning

confidence: 99%

See 1 more Smart Citation

Influence of transverse mode on retinal spot size and retinal injury effect: A theoretical analysis on 532-nm laser

Wang¹,

Yang³

et al. 2014

J. Innov. Opt. Health Sci.

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The fundamental transverse mode (TEM 00 Þ is preferable for experimental and theoretical study on the laser-induced retinal injury e®ect, for it can produce the minimal retinal image and establish the most strict laser safety standards. But actually lasers with higher order mode were frequently used in both earlier and recent studies. Generally higher order mode leads to larger retinal spot size and so higher damage threshold, but there are few quantitative analyses on this problem. In this paper, a four-surface schematic eye model is established for human and macaque. The propagation of 532-nm laser in schematic eye is analyzed by the ABCD law of Gaussian optics. It is shown that retinal spot size increases with laser transverse mode order. For relative lower mode order, the retinal spot diameter will not exceed the minimum laser-induced retinal lesion (25 $ 30 m in diameter), and so has little e®ect on retinal damage threshold. While for higher order mode, the larger retinal spot requires more energy to induce injury and so the damage threshold increases. When beam divergence is lowered, the retinal spot size decreases correspondingly, so the e®ect of mode order can be compensated. The retinal spot size of macaque is slightly smaller than that of human and the ratio between them is independent of mode order. We conclude that the laser mode order has signi¯cant in°uence on retinal spot size but limited in°uence on the retinal injury e®ect.

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Section: Methods 21 Embedded Gaussian Model and Abcd Lawmentioning

confidence: 99%

Section: Methods 21 Embedded Gaussian Model and Abcd Lawmentioning

confidence: 99%

Influence of transverse mode on retinal spot size and retinal injury effect: A theoretical analysis on 532-nm laser

Wang¹,

Yang³

et al. 2014

J. Innov. Opt. Health Sci.

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“…21,22 Experiments from Chen et al using various animal models also further confirmed this hypothesis by reporting the ED50 threshold for the cornea to be approximately 9.04 W for a 5 mm beam incident on the cornea. 20 These thresholds are much lower than the retinal hazards for long exposures (0.1 to 10 s); however, a proposed threshold of even 1.0 J ⋅ cm −2 is still very conservative in protecting against cornea, iris, and retina lesions.…”

Section: Safety Considerations At 1319 Nmmentioning

confidence: 99%

“…As a result, it was hypothesized that thermal lensing would significantly influence ocular damage thresholds induced by these lasers. 12,[16][17][18][19][20] Damage threshold experiments at 1319 nm using rhesus models indicate that the 24 h ED50 threshold for a 80 ms exposure is 14.5 W of measured power for a 5 mm beam entering the eye, 12 where ED50 is the amount of energy required to create a minimal visible lesion in 50% of exposures. Based on this series of investigations, it was determined that the current ANSI Z136.1-2007 standard (0.072 J ⋅ cm −2 , exposure duration of 1 s for wavelengths between 1200 and 1400 nm) was extremely conservative (approximately 10× lower) than necessary in order to meet the universally accepted margin of safety (10% of the ED50).…”

Section: Safety Considerations At 1319 Nmmentioning

confidence: 99%

Visual disruption using the thermal lensing effect in the human eye: pilot study

Towle

Garcia²,

Smith³

et al. 2012

J. Biomed. Opt

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Abstract. At select wavelengths, near infrared (IR) light is absorbed in the preretinal media of the eye. This produces small transient increases in temperature that temporarily alter the local index of refraction. If the IR exposure is sufficiently high, a momentary reduction in the focusing power of the eye can be induced through an effect known as thermal lensing. Fundamental optical interaction and safety aspects of this phenomenon have been demonstrated previously in animal and artificial eye models. However, whether the effect will induce an observable visual change in human subjects has not been explored. Here, results of a pilot study are shown where eight human subjects were exposed to an IR laser at levels that were below the safe exposure limit. The exposures did induce a transient visual distortion if sufficiently high levels were used. While the description of the visual change varied between subjects, this experiment was able to determine a general guideline for power needed to induce significant effects in human subjects.

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“…Due to the widespread use of laser systems in this region and the rapid increase of laser power/energy, the risk of ocular damage becomes more serious and thus receives more concern [3]. In the past two decades, ocular damage threshold studies have been conducted at diverse laser radiation parameters to quantify the ocular hazards [1][2][3][4][5][6][7][8][9][10][11][12][13]. International safety committees, such as the International Commission of Non-Ionizing Radiation Protection (ICNIRP) and the American National Standards Institute (ANSI), analyze these damage threshold studies and make recommendations for the Maximum Permissible Exposures (MPEs) [14,15].…”

Section: Introductionmentioning

confidence: 99%

Ocular damage effects from 1338-nm pulsed laser radiation in a rabbit eye model

Jiao

Wang

Jing

et al. 2017

Biomed. Opt. Express

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The ocular damage effects induced by transitional near-infrared (NIR) lasers have been investigated for years. However, no retinal damage thresholds are determined in a wide interval between 0.65 ms and 80 ms, and a definite relationship between corneal damage threshold and spot size cannot be drawn from existing data points. In this paper, the corneal damage thresholds (EDs) were determined in New Zealand white rabbits for a single 5 ms pulse at the wavelength of 1338 nm for spot sizes from 0.28 mm to 3.55 mm. Meanwhile, the retinal damage threshold for this laser was determined in chinchilla grey rabbits under the condition that the beam was collimated, and the incident corneal spot diameter was 5.0 mm. The corneal EDs given in terms of the corneal radiant exposure for spot diameters of 0.28, 0.94, 1.91, and 3.55 mm were 70.3, 35.6, 29.6 and 30.3 J/cm, respectively. The retinal ED given in terms of total intraocular energy (TIE) was 0.904 J. The most sensitive ocular tissue to this laser changed from the cornea to retina with the increase of spot size.

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A comparative study on ocular damage induced by 1319nm laser radiation

Cited by 11 publications

References 27 publications

Influence of transverse mode on retinal spot size and retinal injury effect: A theoretical analysis on 532-nm laser

Influence of transverse mode on retinal spot size and retinal injury effect: A theoretical analysis on 532-nm laser

Visual disruption using the thermal lensing effect in the human eye: pilot study

Ocular damage effects from 1338-nm pulsed laser radiation in a rabbit eye model

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