title: A quantitative approach to identify morphological features relevant for visual function in ranibizumab therapy of neovascular AMD.
abstract: OBJECTIVE
  To quantitatively analyze morphological features in eyes with neovascular AMD (nAMD) at baseline, after 12 months, and after 24 months of intravitreal ranibizumab treatment and to perform a structure/function correlation.
  
  
  METHODS
  Eyes with treatment-naïve nAMD were treated with intravitreal ranibizumab according to a standardized dosing regimen over 2 years and followed continuously in a prospective study design. The central foveal area of 1000 μm (horizontal)×960 μm (vertical) of spectral-domain optical coherence tomography (SD-OCT) volume scans was evaluated quantitatively (using proprietary software) for the following pathologies: alteration of the external limiting membrane (ELM), alteration of the ellipsoid zone, subretinal fluid, pigment epithelium detachment, drusen, intraretinal cysts, subretinal mass, and subretinal pigment epithelium mass. The total area of each pathology was calculated in mm2 at baseline and after 1 and 2 years of ranibizumab therapy and correlated with BCVA results.
  
  
  RESULTS
  In total, 480 central SD-OCT scans of 20 consecutive patients were evaluated. In the multivariate regression analysis, the area of ELM alteration, the area of intraretinal cysts, and foveal retinal thickness were significant variables influencing visual acuity at baseline (R=-0.827; R2=0.684; P<0.001). The area of ELM alteration was the only significant factor to be directly associated with visual acuity at 12 months (R=-0.846; R2=0.716; P<0.001) and 24 months (R=-0.778; R2=0.606; P<0.001).
  
  
  CONCLUSIONS
  The integrity of the ELM appears to be the most important feature correlating with visual acuity in native nAMD as well as nAMD treated with intravitreal ranibizumab at each time interval, but not prospectively. In general, no significant predictors for an individual gain or loss in mid- (12 months) or long-term BCVA results (24 months) were found by OCT.
authors.affiliation: Department of Ophthalmology and Optometry of the Medical University Vienna, Vienna, Austria.
authors.forename: Philipp
authors.initials: P
authors.lastname: Roberts
authors.affiliation: Department of Ophthalmology and Optometry of the Medical University Vienna, Vienna, Austria.
authors.forename: Tamara Jasmin
authors.initials: TJ
authors.lastname: Mittermueller
authors.affiliation: Department of Ophthalmology and Optometry of the Medical University Vienna, Vienna, Austria.
authors.forename: Alessio
authors.initials: A
authors.lastname: Montuoro
authors.affiliation: Department of Ophthalmology and Optometry of the Medical University Vienna, Vienna, Austria.
authors.forename: Florian
authors.initials: F
authors.lastname: Sulzbacher
authors.affiliation: Department of Ophthalmology and Optometry of the Medical University Vienna, Vienna, Austria.
authors.forename: Marion
authors.initials: M
authors.lastname: Munk
authors.affiliation: Department of Ophthalmology and Optometry of the Medical University Vienna, Vienna, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Sacu
authors.affiliation: Department of Ophthalmology and Optometry of the Medical University Vienna, Vienna, Austria.
authors.forename: Ursula
authors.initials: U
authors.lastname: Schmidt-Erfurth
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005451:Fluorescein Angiography; D005500:Follow-Up Studies; D005654:Fundus Oculi; D006801:Humans; D058449:Intravitreal Injections; D008268:Macular Degeneration / Q000188:drug therapy / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D000069579:Ranibizumab; D015861:Retinal Neovascularization / Q000188:drug therapy / Q000473:pathology* / Q000503:physiopathology; D055213:Retinal Pigment Epithelium / Q000187:drug effects / Q000473:pathology*; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D014792:Visual Acuity
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000069579:Ranibizumab
keywords: neovascular AMD; ranibizumab; spectral-domain OCT