title: A comparison of the diagnostic ability of vessel density and structural measurements of optical coherence tomography in primary open angle glaucoma.
abstract: OBJECTIVE
  To compare the diagnostic abilities of vessel density measurements of the optic nerve head (ONH), peripapillary and macular regions on optical coherence tomography (OCT) angiography in eyes with primary open angle glaucoma (POAG) with that of the ONH rim area, peripapillary retinal nerve fiber layer (RNFL) thickness and the macular ganglion cell complex (GCC) thickness measurements.
  
  
  METHODS
  In a cross sectional study, 78 eyes of 50 control subjects and 117 eyes of 67 POAG patients underwent vessel density and structural measurements with spectral domain OCT. POAG was diagnosed based on the masked evaluation of optic disc stereo photographs. Area under receiver operating characteristic curves (AUC) and sensitivities at fixed specificities of vessel densities in ONH, peripapillary and macular regions were compared with rim area, RNFL and GCC thickness.
  
  
  RESULTS
  The AUC (sensitivity at 95% specificity) of average vessel densities within the ONH, peripapillary and macular region were 0.77 (31%), 0.85 (56%) and 0.70 (18%) respectively. The same of ONH rim area, average RNFL and GCC thickness were 0.94 (83%), 0.95 (72%) and 0.93 (62%) respectively. AUCs of vessel densities were significantly lower (p<0.05) than that of the corresponding structural measurements. Pre-treatment IOP (coefficient: 0.08) affected (p<0.05) the AUC of ONH vessel density but not of any other vessel density or structural measurements.
  
  
  CONCLUSIONS
  Diagnostic abilities of ONH, peripapillary and the macular vessel densities in POAG were significantly lower than ONH rim area, peripapillary RNFL and macular GCC measurements respectively. At fixed levels of glaucoma severity, the diagnostic ability of the ONH vessel density was significantly greater in eyes with higher pre-treatment IOP.
authors.affiliation: Narayana Nethralaya, Rajajinagar, Bangalore, India.|Narayana Nethralaya, Hulimavu, Bangalore, India.
authors.forename: Harsha L
authors.identifier: http://orcid.org/0000-0001-5866-9856
authors.initials: HL
authors.lastname: Rao
authors.affiliation: Narayana Nethralaya, Rajajinagar, Bangalore, India.
authors.forename: Zia S
authors.initials: ZS
authors.lastname: Pradhan
authors.affiliation: Shiley Eye Institute, Hamilton Glaucoma Center and Department of Ophthalmology, University of California San Diego, San Diego, La Jolla, California, United States of America.
authors.forename: Robert N
authors.initials: RN
authors.lastname: Weinreb
authors.affiliation: Narayana Nethralaya, Hulimavu, Bangalore, India.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Riyazuddin
authors.affiliation: Narayana Nethralaya, Hulimavu, Bangalore, India.
authors.forename: Srilakshmi
authors.initials: S
authors.lastname: Dasari
authors.affiliation: Narayana Nethralaya, Rajajinagar, Bangalore, India.
authors.forename: Jayasree P
authors.initials: JP
authors.lastname: Venugopal
authors.affiliation: Narayana Nethralaya, Rajajinagar, Bangalore, India.|Narayana Nethralaya, Hulimavu, Bangalore, India.
authors.forename: Narendra K
authors.initials: NK
authors.lastname: Puttaiah
authors.affiliation: Narayana Nethralaya, Rajajinagar, Bangalore, India.
authors.forename: Dhanaraj A S
authors.initials: DA
authors.lastname: Rao
authors.affiliation: Narayana Nethralaya, Rajajinagar, Bangalore, India.
authors.forename: Sathi
authors.initials: S
authors.lastname: Devi
authors.affiliation: Glaucoma Center, Montchoisi Clinic, Swiss Vision Network, Lausanne, Switzerland.|Department of Ophthalmology, University of Colorado, Denver, Colorado, United States of America.
authors.forename: Kaweh
authors.initials: K
authors.lastname: Mansouri
authors.affiliation: University Eye Clinic Maastricht, University Medical Center, Maastricht, the Netherlands.
authors.forename: Carroll A B
authors.initials: CA
authors.lastname: Webers
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D005902:Glaucoma, Open-Angle / Q000000981:diagnostic imaging*; D006801:Humans; D007429:Intraocular Pressure; D008266:Macula Lutea / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D009898:Optic Disk / Q000000981:diagnostic imaging; D011446:Prospective Studies; D012372:ROC Curve; D012165:Retinal Ganglion Cells; D012171:Retinal Vessels / Q000000981:diagnostic imaging*; D041623:Tomography, Optical Coherence / Q000379:methods*