Importance of subfoveal fluid height on visual outcome in macula-off retinal detachments.

Abstract

To investigate the effect of subfoveal fluid height (SFFH) on visual outcome after macula-off retinal detachment (RD) repair. Prospective interventional case series of consecutive patients undergoing pars plana vitrectomy with gas tamponade (PPV) for primary macula-off RD with duration of symptomatic loss of central vision (LCV) of ≤1 week. Preoperative SFFH was measured on two occasions an hour apart using optical coherence tomography (OCT) by two independent observers. Postoperative best corrected visual acuity (BCVA) was measured at 3 months. Sixty-one patients were included. All patients were pseudophakic after RD repair. The mean preoperative and postoperative BCVA (logarithm of the minimum angle of resolution) at 3 months was 1.41 (±0.71) and 0.15 (±0.12, range 0.00-0.70). Twenty-six patients with SFFH of ≤1500 µm were available for repeat OCT measurements. The variation in SFFH was proportional to the SFFH and showed a logarithmic (base 2) association (r=0.50, p=0.01). Patients were therefore grouped according to their SFFH as group 1: 1-100 µm, group 2: 101-300 µm, group 3: 301-700 µm, group 4: 701-1500 µm and group 5: 1501-3100 µm. BCVA at 3 months significantly reduced with increasing SFFH from 0.04 (±0.03) in group 1 to 0.28 (±0.15) in group 5 (p<0.001) but was not associated with age (p=0.77), preoperative BCVA (p=0.39), duration of LCV (p=0.63) or use of perfluorocarbon liquids (p=0.88). Forty-five patients had SFFH ≤1500 µm and achieved 0.10 (±0.07, range 0.00-0.30) logMAR. Visual acuity following PPV for macula-off RD is related to preoperative SFFH regardless of the duration of symptomatic LCV within the first week.