title: The effects of chalazion excision on corneal surface aberrations.
abstract: OBJECTIVE
  This study is the first to consider the effects of chalazion on corneal surface aberrations taking into account of corneal zones, and to establish the size standard for the excision of chalazion.
  
  
  METHODS
  Twenty three eyes from 23 patients with central upper eyelid chalazion larger than 3mm were recruited in this prospective study. The participants were classified into two groups, depending on size of the lesion: Group 1 with lesion size 3-5mm and Group 2 with lesion size >5mm Chalazion was excised by standard transconjunctival vertical incision. Corneal surface aberrations were measured using a Galilei™ analyzer and an auto-refractometer before and 2 months after the excision.
  
  
  RESULTS
  Corneal astigmatism in all patients decreased significantly in both auto refractometer (P=0.012) and Galilei™ (P=0.020) measurements after chalazion excision. RMS of total HOAs decreased significantly in 6mm (P=0.043) and 3mm zone (P=0.051). The RMS of Zernike orders in the vertical and horizontal trefoil decreased significantly in 6mm (P=0.035) and 3mm (P=0.041) zone. Group 2 showed a significant decrease in corneal astigmatism in both auto refractometer (P=0.040) and Galilei™ (P=0.017) parameters after chalazion excision. Group 1 showed an insignificant decrease in corneal astigmatism. Unlike Group 1, the RMS of total HOAs and vertical and horizontal trefoil in 6mm zone decreased significantly in Group 2 (P<0.05).
  
  
  CONCLUSIONS
  The existence of an upper lid chalazion increases astigmatism and HOAs, especially at the peripheral cornea. Significantly induced astigmatism and HOAs are caused by chalazion >5mm in size. Thus, we recommend the surgical excision of chalazion >5mm in size to reduce corneal surface aberrations.
authors.affiliation: Department of Ophthalmology, School of Medicine, Pusan National University & Medical Research Institute, Pusan National University Hospital, Busan, South Korea. Electronic address: loveis293@naver.com.
authors.forename: Young Min
authors.initials: YM
authors.lastname: Park
authors.affiliation: Department of Ophthalmology, School of Medicine, Pusan National University & Medical Research Institute, Pusan National University Hospital, Busan, South Korea. Electronic address: jongsooluw@gmail.com.
authors.forename: Jong Soo
authors.initials: JS
authors.lastname: Lee
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000209:etiology / Q000503:physiopathology*; D017043:Chalazion / Q000150:complications / Q000601:surgery*; D003315:Cornea / Q000473:pathology / Q000503:physiopathology*; D019781:Corneal Topography / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012029:Refraction, Ocular; D014792:Visual Acuity; D055815:Young Adult
keywords: Astigmatism; Chalazion; Galilei™ analyzer; High-order aberrations