Chen Ko-Hua, Cheng Wen-Ting, Li Mei-Jane, Lin Shan-Yang
Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China.
Graefes Arch Clin Exp Ophthalmol. 2006 Mar;244(3):407-10. doi: 10.1007/s00417-005-1191-0. Epub 2005 Aug 13.
The aim of this study was to quickly and quantitatively detect the chemical composition of the calcified deposit on the surface of a surgically excised cornea by using vibrational microspectroscopy.
Both attenuated total reflection (ATR)/Fourier transform infrared (FTIR) and confocal Raman microspectroscopies were used to evaluate the chemical composition of the excised corneal calcified opaque deposit of a 50-year-old male patient. Hydroxyapatite (HA) was used as a reference.
Microscopic observations indicated that a whitish-grayish opaque plaquelike deposit was observed. A peak at 1020 cm(-1) assigned to the stretching vibration of phosphate of the poorly crystalline, immature and nonstoichiometric HA was observed from the IR spectrum of the corneal calcified deposit, as compared with the peak at 1030 cm(-1) of the mature, crystalline and stoichiometric HA reference sample. Higher contents of two IR spectral peaks at 871 cm(-1) due to the type-B carbonated apatite and at 866 cm(-1) corresponded to a labile carbonate were also evidenced in the corneal calcified deposit. The predominate peak at 959 cm(-1) due to the stretching mode of phosphate was also found in the Raman spectrum of corneal calcified deposit.
The corneal calcified deposit was evidenced to contain much poor crystalline and immature HA having higher content of the type-B carbonated apatite within the corneal collagen matrix. The process of corneal calcification still proceeds on the surface of this cornea.
本研究的目的是通过振动光谱法快速定量检测手术切除角膜表面钙化沉积物的化学成分。
采用衰减全反射（ATR）/傅里叶变换红外（FTIR）光谱和共焦拉曼光谱对一名50岁男性患者切除的角膜钙化混浊沉积物的化学成分进行评估。以羟基磷灰石（HA）作为参照。
显微镜观察表明，观察到灰白色不透明斑块状沉积物。与成熟、结晶和化学计量的HA参照样品在1030 cm⁻¹处的峰相比，在角膜钙化沉积物的红外光谱中观察到一个1020 cm⁻¹处的峰，该峰归属于结晶度差、不成熟和非化学计量的HA中磷酸盐的伸缩振动。角膜钙化沉积物中还证实了因B型碳酸化磷灰石在871 cm⁻¹处和对应不稳定碳酸盐在866 cm⁻¹处的两个红外光谱峰含量更高。在角膜钙化沉积物的拉曼光谱中也发现了因磷酸盐伸缩模式在959 cm⁻¹处的主峰。
证实角膜钙化沉积物在角膜胶原基质中含有大量结晶度差和不成熟的HA，且B型碳酸化磷灰石含量更高。该角膜表面的角膜钙化过程仍在进行。
