title: Frequency-doubling technology perimetry for detection of the development of visual field defects in glaucoma suspect eyes: a prospective study.
abstract: OBJECTIVE
  While standard automated perimetry (SAP) remains the reference standard for evaluation of visual field (VF) defects in glaucoma, this study demonstrates that frequency-doubling technology (FDT) perimetry is effective in monitoring visual field progression and may detect the onset of visual field defects earlier than SAP.
  
  
  OBJECTIVE
  To compare detection of the development of VF defects, rate of change of VF loss, and risk factors for progression between SAP and matrix FDT perimetry in glaucoma suspect and ocular hypertensive eyes.
  
  
  METHODS
  A total of 113 glaucoma suspect and ocular hypertensive eyes from 76 patients with normal SAP and FDT perimetry results at baseline were prospectively followed up for SAP and FDT perimetry testing at approximately 4-month intervals for 30 months or longer. Patients were consecutively enrolled and followed up from January 2, 2008, to February 28, 2012, at the Hong Kong Eye Hospital, Chinese University of Hong Kong. Visual field progression was defined by the development of VF defects confirmed by 3 or more consecutive examinations at a cluster of 3 or more (less conservative) or 4 or more (more conservative) locations. The rates of change of mean deviation and pattern standard deviation were evaluated with linear mixed models and the risk factors for VF progression were computed with Cox proportional hazard models.
  
  
  RESULTS
  During a median study period of 3.4 years, 8.0% of eyes developed VF defects detected by FDT perimetry, 6.2% by SAP, and 4.4% by both using the less-conservative criteria. The detection dropped to 6.2%, 4.4%, and 2.7%, respectively, when the more-conservative criteria were applied. The rate of change of pattern standard deviation was significantly faster for FDT perimetry than SAP (P < .001). Baseline average retinal nerve fiber layer thickness and the number of clock hours of abnormal retinal nerve fiber layer measurement were associated with increased risk for VF progression for both SAP and FDT perimetry.
  
  
  CONCLUSIONS
  Frequency-doubling technology perimetry would be useful to monitor the onset of VF defects in glaucoma and may detect VF defects not evident in SAP.
authors.affiliation: Department of Ophthalmology and Visual Sciences, Chinese University of Hong Kong, Hong Kong, People's Republic of China.
authors.forename: Shu
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Ophthalmology and Visual Sciences, Chinese University of Hong Kong, Hong Kong, People's Republic of China.
authors.forename: Marco
authors.initials: M
authors.lastname: Yu
authors.affiliation: Hamilton Glaucoma Center and the Department of Ophthalmology, University of California, San Diego.
authors.forename: Robert N
authors.initials: RN
authors.lastname: Weinreb
authors.affiliation: Department of Ophthalmology and Visual Sciences, Chinese University of Hong Kong, Hong Kong, People's Republic of China.
authors.forename: Gilda
authors.initials: G
authors.lastname: Lai
authors.affiliation: Department of Ophthalmology and Visual Sciences, Chinese University of Hong Kong, Hong Kong, People's Republic of China.
authors.forename: Dennis Shun-Chiu
authors.initials: DS
authors.lastname: Lam
authors.affiliation: Department of Ophthalmology and Visual Sciences, Chinese University of Hong Kong, Hong Kong, People's Republic of China.
authors.forename: Christopher Kai-Shun
authors.initials: CK
authors.lastname: Leung
mesh_terms: D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology; D009798:Ocular Hypertension / Q000175:diagnosis*; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012165:Retinal Ganglion Cells / Q000473:pathology; D012307:Risk Factors; D041623:Tomography, Optical Coherence; D014065:Tonometry, Ocular; D014786:Vision Disorders / Q000175:diagnosis*; D058609:Visual Field Tests / Q000379:methods*; D014794:Visual Fields