Preliminary Identification of β-Carotene in the Vitreous Asteroid Bodies by Micro-Raman Spectroscopy and HPLC Analysis

β-carotene was first identified from the vitreous asteroid bodies (ABs) excised from one patient with asteroid hyalosis (AH) by confocal Raman microspectroscopy and was also verified by high performance liquid chromatography (HPLC). Two patients had been diagnosed with AH and intervened by surgical vitrectomy due to blurred vision. The morphology and components of both AB specimens were observed by optical microscopy and determined by using confocal Raman microspectroscopy and HPLC analysis, respectively. Surprisingly, two unique peaks at 1528 and 1157 cm⁻¹were found in the Raman spectrum for the AB specimen of patient 1 alone, which were in close agreement with that of the Raman peaks at 1525 and 1158 cm⁻¹for β-carotene and/or lutein. However, HPLC analytical data clearly indicated that the retention time for the extracted sample from the AB specimen of patient 1 was observed at 13.685 min and just identical to that of β-carotene (13.759 min) rather than lutein (2.978 min). In addition, the lack of any peak in the HPLC profile for the AB specimen of patient 2 also confirmed the absence of Raman peaks at 1525 and 1158 cm⁻¹. Thus this preliminary study strongly suggests that β-carotene as a unique component of ABs was specifically detected from the AB specimen of one AH patient by using confocal Raman microspectroscopy and HPLC analysis.