title: Pterygium is related to a decrease in corneal endothelial cell density.
abstract: OBJECTIVE
  The aim of this study was to investigate the relationship between pterygium and a decrease in the corneal endothelial cell density (ECD) in patients with unilateral primary pterygium.
  
  
  METHODS
  In this retrospective cross-sectional study, 90 consecutive patients with unilateral primary pterygium were enrolled from January 2010 to June 2012. Corneal ECD was measured in both eyes, and the fellow eyes were considered as controls. The relationship between the percentage of pterygium to cornea and a decrease in the ECD was analyzed. An increase in astigmatism in eyes with pterygium was evaluated for association with decreased ECD using the Pearson correlation test.
  
  
  RESULTS
  The percentage of pterygium to cornea ranged from 3.5% to 65.2%, with a median of 12.35%. The difference in the corneal ECD between eyes with pterygium and control eyes ranged from +9.6% to -37.7%, with a median of -9.75%. The results of the Pearson correlation statistical test showed a strong logarithmic correlation between a decrease in the corneal ECD and the percentage of pterygium to cornea (R = 0.688, P < 0.001). An increase in astigmatism was correlated with a decrease in the ECD in eyes with pterygium.
  
  
  CONCLUSIONS
  Pterygium is related to a decrease in corneal ECD. Surgical intervention should be considered in patients with extensive pterygium involvement in the cornea or a significant increase in astigmatism.
authors.affiliation: *Department of Ophthalmology, Taichung Veterans General Hospital, Taichung, Taiwan; and †The Institute of Nanoengineering and Microsystems, National Tsing Hua University, Hsinchu, Taiwan.
authors.forename: Min-Yen
authors.initials: MY
authors.lastname: Hsu
authors.forename: Hsin-Nung
authors.initials: HN
authors.lastname: Lee
authors.forename: Chiao-Ying
authors.initials: CY
authors.lastname: Liang
authors.forename: Li-Chen
authors.initials: LC
authors.lastname: Wei
authors.forename: Chun-Yuan
authors.initials: CY
authors.lastname: Wang
authors.forename: Keng-Hung
authors.initials: KH
authors.lastname: Lin
authors.forename: Ying-Cheng
authors.initials: YC
authors.lastname: Shen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001251:Astigmatism / Q000175:diagnosis; D002452:Cell Count; D055954:Corneal Endothelial Cell Loss / Q000150:complications* / Q000175:diagnosis; D003430:Cross-Sectional Studies; D004728:Endothelium, Corneal / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011625:Pterygium / Q000150:complications* / Q000175:diagnosis / Q000601:surgery; D012189:Retrospective Studies