Abnormal epithelial differentiation and tear film alteration in pinguecula.
OBJECTIVE
To investigate the differentiation of conjunctival epithelium and tear film function in pingueculae.


METHODS
Twelve patients (12 eyes) who underwent simple excision for pingueculae were enrolled in the study. Immunostaining for K14, K19, K10, MUC5AC, Pax6, P63, Ki67, and K16 was performed on the pinguecula epithelium and normal conjunctival epithelium. Schirmer I test results and tear film break-up time (TFBUT) were evaluated just before and 1 month after surgery.


RESULTS
Abnormal epidermal differentiation of pinguecula tissue, as evidenced by a decline in or absence of Pax6 expression, was accompanied by a decline in or absence of K19 keratin and MUC5AC, and an increase in K10 and K14 keratin. Furthermore, the pinguecula epithelium was actively proliferating, as evidenced by positive expression of Ki67, P63, and K16 keratin. The Schirmer I test results did not indicate any significant differences before and after surgery. However, the TFBUT was significantly prolonged 1 month after surgery compared with before surgery.


CONCLUSIONS
Pinguecula is a condition of abnormal epithelial differentiation. It is characterized by squamous proliferation and metaplasia, resulting in instability of tear film with normal basic tear secretion.
Dong
Nuo
N
Eye Institute and affiliated Xiamen Eye Center of Xiamen University, Fujian, China.
Li
Wei
W
Lin
Hui
H
Wu
Huping
H
Li
Cheng
C
Chen
Wensheng
W
Qin
Wenjuan
W
Quyang
Luowa
L
Wang
Hua
H
Liu
Zuguo
Z
D000328:Adult; D002454:Cell Differentiation; D003228:Conjunctiva / Q000378:metabolism / Q000473:pathology*; D003229:Conjunctival Diseases / Q000378:metabolism* / Q000473:pathology* / Q000601:surgery; D003941:Diagnostic Techniques, Ophthalmological; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology*; D005136:Eye Proteins / Q000378:metabolism; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D018398:Homeodomain Proteins / Q000378:metabolism; D006801:Humans; D053530:Keratins, Type I / Q000378:metabolism; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D008875:Middle Aged; D055271:Mucin 5AC / Q000378:metabolism; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D013666:Tears / Q000378:metabolism*
C081876:CKAP4 protein, human; D005136:Eye Proteins; D018398:Homeodomain Proteins; D053530:Keratins, Type I; D019394:Ki-67 Antigen; C524678:MUC5AC protein, human; D008565:Membrane Proteins; D055271:Mucin 5AC; D000071841:PAX6 Transcription Factor; C000605730:PAX6 protein, human; D051761:Paired Box Transcription Factors; D012097:Repressor Proteins