Effects of retinal morphology on contrast sensitivity and reading ability in neovascular age-related macular degeneration.
OBJECTIVE
To investigate the effect of changes in retinal morphology on contrast sensitivity and reading ability in patients with neovascular age-related macular degeneration (AMD) in the Avastin (bevacizumab; Genentech, South San Francisco, CA) for choroidal neovascularization (ABC) Trial.


METHODS
Contrast sensitivity obtained with Pelli-Robson charts, reading ability assessed with Minnesota Reading charts, and Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity (VA) obtained by protocol refraction, were recorded. Raw Stratus optical coherence tomography (OCT; Carl Zeiss Meditec, Inc., Dublin, CA) images were analyzed with the publicly available software OCTOR, which allows precise delineation of any retinal compartment of interest. Thickness and volume were calculated for neurosensory retina, subretinal fluid (SRF), subretinal tissue, and pigment epithelium detachment, and the resulting measurements were correlated with each visual function parameter.


RESULTS
One hundred twenty-two patients with newly diagnosed neovascular AMD and enrolled in the ABC Trial, were evaluated. Increased subretinal tissue volume correlated with decreased contrast sensitivity (Pearson's correlation coefficient, r = -0.4944, P = 0.001). A modest correlation was detected between SRF volume and contrast sensitivity (r = -0.2562, P = 0.004). Increased retinal thickness at the foveal center also correlated with decreased visual function (ETDRS VA: r = -0.4530, P < 0.001).


CONCLUSIONS
The strongest correlation detected between the functional parameters assessed and any of the OCT-derived morphologic parameters was that between decreased contrast sensitivity and increased subretinal tissue. In the future, assessment of contrast sensitivity and reading ability, in combination with quantitative subanalysis of retinal compartments, may lead to the identification of parameters relevant to functional improvement and ultimate prognosis in patients with newly diagnosed neovascular AMD (www.controlled-trials.com number, ISRCTN83325075).
Keane
Pearse A
PA
Doheny Image Reading Center, Doheny Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, USA.
Patel
Praveen J
PJ
Ouyang
Yanling
Y
Chen
Fred K
FK
Ikeji
Felicia
F
Walsh
Alexander C
AC
Tufail
Adnan
A
Sadda
Srinivas R
SR
D000368:Aged; D000369:Aged, 80 and over; D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D052157:Aptamers, Nucleotide / Q000627:therapeutic use; D000068258:Bevacizumab; D020256:Choroidal Neovascularization / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*; D015350:Contrast Sensitivity / Q000502:physiology*; D003430:Cross-Sectional Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008268:Macular Degeneration / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010778:Photochemotherapy; D011932:Reading; D012160:Retina / Q000473:pathology*; D058471:Subretinal Fluid; D041623:Tomography, Optical Coherence; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors; D014792:Visual Acuity / Q000502:physiology
D020533:Angiogenesis Inhibitors; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D052157:Aptamers, Nucleotide; D042461:Vascular Endothelial Growth Factor A; C495058:pegaptanib; D000068258:Bevacizumab