title: En face spectral-domain optical coherence tomography outer retinal analysis and relation to visual acuity.
abstract: OBJECTIVE
  To describe a method of en face visualization and quantification of the photoreceptor inner segment/outer segment junction area, using spectral-domain optical coherence tomography, and association with visual acuity.
  
  
  METHODS
  Case series of 74 eyes in 53 patients. Central 1-mm and 400-μm en face areas were analyzed with a computer algorithm.
  
  
  RESULTS
  The presence or absence of inner segment/outer segment junction was visible on both spectral-domain optical coherence tomography en face and retinal cross sections. Thirty eyes (40.6%) had no retinal pathology and an average logMAR visual acuity of 0.116. Twenty-five eyes (33.8%) had intraretinal edema, with visual acuity of 0.494. Nineteen eyes had nonneovascular age-related macular degeneration (dry age-related macular degeneration, 25.6%), with visual acuity of 0.392. In all eyes, central 1-mm and 400-μm en face areas were 58.3 ± 25.0% and 56.4 ± 26.0%, which showed significant correlation with visual acuity (Pearson correlation, r = -0.66 and -0.56, both P < 0.001). This correlation was greater than correlation of visual acuity with central subfield thickness (r = 0.39, P < 0.001), macular volume (r = 0.36, P = 0.002), and average macular thickness (r = 0.37, P = 0.001). However, no variables were significantly correlated with dry age-related macular degeneration eyes.
  
  
  CONCLUSIONS
  Central en face inner segment/outer segment junction areas are significantly correlated with visual acuity in most eyes. This may correlate better with visual acuity than other spectral-domain optical coherence tomography values, as a reflection of photoreceptor integrity. Dry age-related macular degeneration may disrupt the plane used to formulate the en face display. Advancements in spectral-domain optical coherence tomography may provide routine en face visualization analysis.
authors.affiliation: Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, Illinois, USA.
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Kiernan
authors.forename: Ruth
authors.initials: R
authors.lastname: Zelkha
authors.forename: Seenu M
authors.initials: SM
authors.lastname: Hariprasad
authors.forename: Jennifer I
authors.initials: JI
authors.lastname: Lim
authors.forename: Michael P
authors.initials: MP
authors.lastname: Blair
authors.forename: William F
authors.initials: WF
authors.lastname: Mieler
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D012164:Retinal Diseases / Q000175:diagnosis* / Q000503:physiopathology; D055211:Retinal Photoreceptor Cell Inner Segment / Q000473:pathology*; D055214:Retinal Photoreceptor Cell Outer Segment / Q000473:pathology*; D041623:Tomography, Optical Coherence / Q000379:methods*; D014792:Visual Acuity / Q000502:physiology*