title: The Influence of Overnight Orthokeratology on Ocular Surface and Meibomian Glands in Children and Adolescents.
abstract: OBJECTIVE
  The aim of this study was to investigate the influence of overnight orthokeratology (OOK) on ocular surface and meibomian glands in children and adolescents.
  
  
  METHODS
  Prospective, noncomparative study included the ocular surface disease index (OSDI), tear osmolarity, corneal and conjunctival fluorescein staining, tear film breakup time (TBUT), the Schirmer I test, and meiboscore using noncontact meibography. Immunofluorescence confocal microscopy of interleukin-1β (IL1β), interleukin-6 (IL6), epidermal growth factor (EGF), and matrix metalloproteinase (MMP)-9 using impression cytology filter paper was performed. The tests were performed before and at 6, 12, 24, and 36 months after OOK wear.
  
  
  RESULTS
  Fifty-eight subjects using OOK were observed. Significant increases in OSDI score (P=0.0009) and corneal and conjunctival staining score (P<0.0001) were observed compared with baseline values at 36 and 24 months, respectively. Ocular surface and meibomian changes were noted in 2 patients (3.5%). One patient exhibited an increase in OSDI score, concurrent with a decrease in TBUT at 36 months and minor loss of the meibomian gland at the distal portion of the lower lid at 24 months. The other patients exhibited the development of papillary hypertrophy and meibomian gland distortion at 24 months. No significant changes were detected in IL1β, IL6, EGF, or MMP expression after OOK use.
  
  
  CONCLUSIONS
  Based on the findings, OOK was a relatively safe modality. However, given the potential changes in the meibomian gland and tear film stability, special attention must be paid to children with baseline meibomian gland distortions or a history of allergic conditions.
authors.affiliation: Department of Ophthalmology and Visual Science (K.-S.N., H.S.K.), Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea; Department of Ophthalmology and Visual Science (C.-K.J.), Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea; Catholic Institutes of Visual Science (K.-S.N., Y.-S.Y., J.W.M.), The Catholic University of Korea, Seoul, Korea; and Department of Ophthalmology (H.S.H.), Chuncheon Sacred Heart Hospital, College of Medicine, Hallym University, Chuncheon, Korea.
authors.forename: Kyung-Sun
authors.initials: KS
authors.lastname: Na
authors.forename: Young-Sik
authors.initials: YS
authors.lastname: Yoo
authors.forename: Ho Sik
authors.initials: HS
authors.lastname: Hwang
authors.forename: Jee Won
authors.initials: JW
authors.lastname: Mok
authors.forename: Hyun Seung
authors.initials: HS
authors.lastname: Kim
authors.forename: Choun-Ki
authors.initials: CK
authors.lastname: Joo
mesh_terms: D000293:Adolescent; D002648:Child; D003229:Conjunctival Diseases / Q000209:etiology* / Q000378:metabolism / Q000473:pathology; D003316:Corneal Diseases / Q000209:etiology* / Q000378:metabolism / Q000473:pathology; D004815:Epidermal Growth Factor / Q000378:metabolism; D005141:Eyelid Diseases / Q000209:etiology* / Q000378:metabolism / Q000473:pathology; D005260:Female; D019793:Fluorescein / Q000378:metabolism; D006801:Humans; D053583:Interleukin-1beta / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D008537:Meibomian Glands / Q000378:metabolism; D009216:Myopia / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D054158:Orthokeratologic Procedures / Q000009:adverse effects; D011446:Prospective Studies; D013666:Tears / Q000378:metabolism
chemical_list: C508600:IL6 protein, human; D053583:Interleukin-1beta; D015850:Interleukin-6; D004815:Epidermal Growth Factor; D020780:Matrix Metalloproteinase 9; D019793:Fluorescein