Longitudinal changes in each retinal layer thickness in patients with non-ischemic central retinal vein occlusion

BackgroundTo identify longitudinal changes in each retinal layer thickness in central retinal vein occlusion (CRVO) patients with resolved macular edema (ME).MethodsIn this retrospective observational study, CRVO patients without a recurrence of ME for more than 3 years and normal controls were enrolled. Each retinal layer thickness of the parafoveal area, including ganglion cell complex (GCC), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), photoreceptor layer (PRL), and retinal pigment epithelium (RPE) was measured. After the resolution of ME, three more examinations with a 1-year interval were analyzed.ResultsA total of 98 eyes were enrolled, 50 eyes for the control group and 48 eyes for the CRVO group. The baseline GCC thickness was 114.2 +/- 15.6 mu m and 104.2 +/- 25.4 mu m in the control and CRVO groups, respectively, which was significantly different (P = 0.022). The thicknesses of other layers including INL, OPL, ONL, PRL, and RPE were not significantly different at baseline. The reduction rate of GCC, INL, OPL, and ONL was - 3.92, - 1.33, - 0.91, and - 2.31 mu m/year in the CRVO group, whereas no significant reductions were observed in the control group. Best-corrected visual acuity was significantly associated with changes in the GCC, OPL, and ONL in the CRVO group.ConclusionsIn patients with CRVO, even in the absence of recurrent ME, retinal damage progresses over time, evidenced by thinning of the inner retina and outer retina including OPL and ONL. These changes may be associated with alterations in visual function.