Purpose:
To correlate spectral domain (SD-OCT) findings in newly diagnosed neovascular AMD with visual acuity (VA) at baseline, 6 and 12 months following the initiation of intravitreal anti-VEGF therapy.
Methods:
A retrospective review of 480 patients treated with intravitreal bevacizumab or ranibizumab for neovascular AMD by a single physician (KBF) over a 6 month interval. Forty eyes of 35 patients were identified as meeting the following criteria: Inclusion criteria: treatment naïve, gradable eye-tracked SD-OCT images at baseline, 6, and 12 months obtained on the Heidelberg Spectralis HRA+OCT. Exclusion criteria: Foveal involving subretinal fibrosis or geographic atrophy at baseline; photodynamic therapy, thermal laser, cataract surgery or YAG capsulotomy during follow-up period; coexisting macular pathology other than AMD. Presence or absence of the following OCT features at the foveal center was recorded at baseline, 6, and 12 months: external limiting membrane (ELM), inner segment/outer segment (IS/OS) junction, retinal pigment epithelium detachment (PED), subretinal fluid (SRF), and cystoid macular edema (CME). Caliper measurements of outer nuclear layer (ONL) thickness at the foveal center were also recorded. Logistic regression analysis and Student’s t-tests were performed to compare mean LogMAR VA at baseline, 6, and 12 months, as well as mean change in VA from baseline to 12 months with the presence or absence of SD-OCT characteristics. Pearson Product Moment correlation was used to evaluate the association between ONL thickness and VA at each time point. Eyes with CME were excluded from the ONL analyses.
Results:
Eyes with a PED at baseline had worse mean VA at 6 and 12 months (p=0.004 and 0.02). Eyes with intact IS/OS at 6 months had better mean VA at 12 months (p=0.01). Mean improvement in vision from 0-12 months was associated with an intact IS/OS and/or ELM at 6 months (p=0.01 and p=0.03). The only baseline SD-OCT feature that had a statistically significant association with better mean VA at 12 months was presence of an intact ELM (p=0.03). There was no significant correlation between outer nuclear layer thickness and VA.
Conclusions:
For patients with newly diagnosed neovascular AMD, eyes with an intact ELM under the fovea at baseline have a better visual prognosis at one year. Eyes with a PED under the fovea at baseline have a worse visual prognosis at one year. Presence of an intact IS/OS and/or ELM at 6 months is positively correlated with improvement in VA from baseline to 12 months.
Keywords: age-related macular degeneration • imaging/image analysis: clinical