[Does OCT morphology provide indications for prognosis of visual acuity after venous occlusion? : SD-OCT analysis in retinal vein occlusion before and after resolution of initial macular edema].

BACKGROUND

Even though macular edema (ME) in patients with retinal vein occlusion (RVO) is resolved after intravitreal treatment with anti-vascular endothelial growth factor (VEGF), impairment of visual acuity (VA) often persists.

OBJECTIVE

A qualitative and quantitative evaluation of spectral domain optical coherence tomography (SD-OCT) images was carried out in patients with RVO and resolved ME to investigate a correlation between retinal morphology and functional results.

MATERIAL AND METHODS

Foveal SD-OCT scans of 13 patients with RVO and resolved ME after treatment were retrospectively evaluated. The thickness of inner retinal layers up to the external limiting membrane (ELM) and up to the photoreceptors in the retinal pigment epithelium (RPE) was measured by automatic segmentation software. Foveal continuity of the four outer hyperreflective bands, the ellipsoid zone of the inner segments (ISe), the ELM, the interdigitation zone (IZ), the RPE and the location of the initial ME were evaluated. Patients with good  (≤ 0.3 logMAR, n = 10) and poor VA (≥ 1.0 logMAR, n = 3) were compared.

RESULTS

Inner retinal layers up to ELM were thinner in the the poor VA group. In the good VA group the initial ME was significantly more often above the ISe and after resolution of ME the ISe tended to be intact more frequently.

CONCLUSION

In patients with poor VA despite resolved ME the inner retinal layers up to the ELM were significantly thinner, which could be a sign of atrophy. Qualitative differences were seen at the photoreceptor level, which could be explained by ischemia or an involvement of the outer retina during initial ME that leads to permanent destruction of the ISe.