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A comparative study on ocular damage induced by 1319nm laser radiation
Author(s) -
Chen Hongxia,
Yang Zaifu,
Wang Jiarui,
Chen Peng,
Qian Huanwen
Publication year - 2011
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/lsm.21052
Subject(s) - retinal , cornea , ophthalmology , retina , rabbit (cipher) , optics , materials science , medicine , physics , mathematics , statistics
Background and Objectives High energy loss of 1,319 nm laser due to pre‐retinal water absorption makes the ocular axial length more critical, while the relative low absorbance of melanin makes retinal pigmented epithelium less contributing, to retinal damage threshold. However, both have never been illustrated experimentally. Here we determined and compared the retinal damage thresholds at this wavelength in three species with different axial lengths and retinal pigmentations. The corneal damage threshold was also determined for further comparative analysis. Materials and Methods The retinal damage thresholds of albino rat, non‐pigmented and pigmented rabbit, and the corneal damage threshold of non‐pigmented rabbit were determined for 0.2 and/or 0.4‐second exposure durations. The incident beam diameter on cornea was 5 mm for rabbit retinal and 2 mm for rat retinal and rabbit corneal lesion. Minimum visible lesions were examined 1‐ and 24‐hour post‐exposure. Probit analysis was used to establish the estimated damage threshold for 50% of exposures (ED 50 ). The direct transmittance of pre‐retinal eye media was used for further comparative analysis. Results The retinal ED 50 of albino rat for 0.2 seconds, non‐pigmented rabbit for 0.2 seconds, 0.4 seconds, pigmented rabbit for 0.4 seconds was 8.8, 12.1, 22.5, 18.5 J/cm 2 (0.28, 2.4, 4.4, 3.6 J in total intraocular energy (TIE)). The corneal ED 50 was 86.1 J/cm 2 . Under the condition of 5 mm beam diameter and 0.4‐second exposure duration, the calculated retinal ED 50 of human was higher, while that of rhesus monkey was lower than the corneal ED 50 . Conclusion For 1,319 nm laser radiation, the ocular axial length has great, while the retinal pigmentation has only slight influence on retinal damage threshold. The relative lower direct transmittance of human eye media makes the retina more resistant to laser lesion, which should be considered when deriving human maximum permissible exposure (MPE). Lasers Surg. Med. 43:306–312, 2011. © 2011 Wiley‐Liss, Inc.