title: Nerve fibre layer changes in highly myopic eyes by optical coherence tomography.
abstract: OBJECTIVE
  The purpose of this study was to investigate any correlations that may exist between retinal nerve fibre layer (RNFL) thickness and high myopia by optical coherence tomography (OCT).
  
  
  METHODS
  Case-control study.
  
  
  METHODS
  Ten patients (20 eyes) with high myopia and 10 control patients (20 eyes) matched for age and sex were recruited from a database search of 1 vitreoretinal practice in Regina, Sask.
  
  
  METHODS
  The RNFL thickness of 10 highly myopic patients and 10 control patients matched for age and sex from a clinical practice was determined using the Stratus OCT. All 10 highly myopic patients selected for the study had a spherical equivalent of > or = -10.0 D OU and an intraocular pressure <21 mm Hg OU, and failed to display glaucomatous changes such as disc hemorrhages and glaucomatous cupping in either eye. None of the patients included in the study had evidence of concomitant ophthalmic disease and none had had previous refractive surgery. Axial length measurements were done on all patients using the IOL Master.
  
  
  RESULTS
  The mean (SD) RNFL thicknesses in the control and myopic groups were 108.8 (10.6) microm and 80.0 (18.6) microm, respectively, with t = 6.0 and p < 0.001. A negative correlation -0.712 with p < 0.001 was found between RNFL thickness and axial length.
  
  
  CONCLUSIONS
  When interpreting the RNFL thickness of highly myopic patients by OCT, careful attention must be given to the inherently thinner RNFL to avoid a false glaucoma diagnosis.
authors.affiliation: Queen's University Ophthalmology, Kingston, Ont., Canada.
authors.forename: Kelly D
authors.initials: KD
authors.lastname: Schweitzer
authors.forename: David
authors.initials: D
authors.lastname: Ehmann
authors.forename: Raúl
authors.initials: R
authors.lastname: García
mesh_terms: D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000175:diagnosis* / Q000503:physiopathology; D009412:Nerve Fibers / Q000473:pathology*; D012029:Refraction, Ocular; D012165:Retinal Ganglion Cells / Q000473:pathology*; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence / Q000379:methods*