Micro-Raman spectroscopy study of human pterygium and conjunctival melanocytic nevi

Pterygium, a common ophthalmic disease that is caused by fibrovascular growth of conjunctiva and conjunctival melanocytic nevi that is another conjunctival disease, are detected by Raman spectroscopy in the present study. We find that there is an obvious increase in the intensity at the peak of 1,583 cm(-1) that is assigned to C=C unsaturated fatty acids stretch of lipids in the pterygium tissue, and 1,639 cm(-1) also increased which belongs to amide I. Also, PCA (Principal Component Analysis) was used to classify the normal conjunctiva from the pterygium tissue. For the conjunctival melanocytic nevi, the intensity of Raman spectrum region between 1,550 cm(-1) and 1,650 cm(-1) that belong to protein has increased, which indicates that the content of protein in conjunctival melanocytic nevi is more richer than the normal ones.