We present an adaptive-optics optical coherence tomography (AO-OCT) system with 3.4-mm beam diameter. A deformable mirror is used for the correction of two radial Zernike orders (defocus, vertical and oblique astigmatism). The aberrations are corrected sequentially with a Shack-Hartmann wave-front sensor and the deformable mirror. This system fills a gap between a standard clinical 1.2-mm beam diameter OCT system and a 6-mm beam diameter AO-OCT system. We also present 8 degrees by 8 degrees en face OCT images from a patient with macular degeneration. This system has a 25 cm by 50 cm footprint, which makes it considerably smaller to conventional 6-mm beam diameter AO-OCT system. Because of its larger field of view and smaller size, it is likely to be useful in the ophthalmic clinics for high-resolution imaging of the human eye retina.