New algorithm for assessing patient suitability for macular translocation surgery

Abstract

We propose a case selection algorithm to assess suitability for macular translocation for subfoveal neovascular membrane (CNV) secondary to age-related macular degeneration. The algorithm is based on preoperative assessment of residual foveal function, as assessed by a slit-lamp fixation task and duration of visual loss, in patients with poor acuity. We validate our slit-lamp fixation task against an objective analysis (Nidek MP-1 Microperimetry) and proceed to examine surgical outcomes as selected by the algorithm. A prospective series of 27 consecutive patients with CNV underwent translocation at Moorfields Eye Hospital, London between May 2003 and May 2006. Validation of the slit-lamp fixation task revealed 100% concordance in classification of fixation between the slit-lamp task and the microperimeter. At an average follow up of 12.2 months, the mean Early Treatment of Diabetic Retinopathy Study distance acuity improved from logMAR 0.88 to 0.68 (P < 0.03). Sixty-six per cent of patients achieved an acuity of < or =logMAR 0.8 (6/30), 22% an acuity of < or =logMAR 0.3 (6/12) and 33% gained three lines of acuity. The mean MN Read reading acuity improved from logMAR 1.23 to 0.91 (P < 0.01). Forty-four per cent of patients achieved an acuity of > or =logMAR 0.7 (N10), 15% an acuity of > or =logMAR 0.4 (N5) and 44% gained three lines of acuity. We have demonstrated a simple case selection algorithm that is based on residual foveal function and suggests good outcomes. The strongest indicators of foveal function are fixation characteristics and duration of visual loss. In contrast to previous studies, our algorithm suggests good outcomes independently of preoperative visual acuity and CNV characteristics.