Data from this study suggested patients who undergo macula-off RRD fare worse compared with those who undergo macula-on RRD. Photo: Andrea Knouff, OD. Click image to enlarge.

Researchers in the United Kingdom recently investigated the relationship between retinal anatomic characteristics, visual acuity and perimetric retinal sensitivity in patients following retinal reattachment surgery, finding that the central outer nuclear layer and outer retinal segment thinning correlated with decreased retinal sensitivity and may be explained by rhegmatogenous retinal detachment (RRD) photoreceptor death. They noted there was greater thinning following macula-off RRD compared with macula-on RRD.

The study assessed 13 macula-on and eight macula-off patients before and six months after vitreoretinal surgery. The researchers recorded OCT thickness of the outer nuclear layer, outer retinal segment, retinal pigment epithelium to ellipsoid zone and external limiting membrane to ellipsoid zone six months post-op. They then compared their findings with BCVA and retinal sensitivity.

The mean outer nuclear layer thickness was higher after macula-on RRD compared with macula-off (97.7μm vs. 73.1μm). Central outer nuclear layer thickness was strongly associated with retinal sensitivity and less strongly with BCVA. In all RRD eyes, every 1μm decrease in outer nuclear layer thickness correlated with a 0.052dB decrease in retinal sensitivity, and every 1μm decrease in outer retinal segment thickness was associated with a 0.062dB reduction in retinal sensitivity. The other thickness measurements did not correlate with BCVA post-retinal reattachment surgery.

The researchers said they believe that retinal detachment causes photoreceptor apoptosis and that foveal cone morphology after reattachment correlates with VA.

“The associations between outer nuclear layer thickness and retinal sensitivity and visual acuity support the hypothesis that photoreceptor apoptosis after macula-off retinal detachment contributes to reduced visual function,” they noted in their paper.

However, because they used clinical examination to distinguish macula-off and macula-on RRD, it is possible that some macula-on RRD patients might have had subclinical subretinal fluid in the macula, limiting the study’s ability to make distinctions between the relationships in macula-on as opposed to macula-off RRD.