Association between individual retinal layer thickness and visual acuity in patients with epiretinal membrane: a pilot study

Abstract

<jats:sec> <jats:title>Purpose</jats:title> <jats:p>We investigated the correlation between visual acuity (VA) and individual retinal layer thickness in the foveal, parafoveal, and perifoveal regions of patients with an idiopathic epiretinal membrane (ERM).</jats:p> </jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>One hundred and five subjects presenting with unilateral idiopathic ERM were included in this study. We segmented each patient’s optical coherence tomography (OCT) image into seven layers and calculated the mean layer thickness in the foveal, parafoveal, and perifoveal regions using the Iowa Reference Algorithm. In 105 patients with ERM, we detected correlations between their macular regions’ individual retinal layer thickness and their best corrected VA. Thirty-one of the 105 patients with ERM underwent vitrectomy and completed six months of follow-up. We then compared the 31 surgical patients’ preoperative and postoperative individual retinal layer thickness in each macular region. Additionally, the association between preoperative individual retinal layer thickness in each macular region and VA six months post-surgery in patients with ≥ two Snellen lines of visual improvement was determined.</jats:p> </jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>Multiple linear regression analysis showed that the inner nuclear layer (INL) thickness in the foveal, parafoveal, and perifoveal region were all associated with VA in the 105 patients (<jats:italic>R</jats:italic><jats:sup>2</jats:sup> = 0.344, <jats:italic>P</jats:italic> &lt; 0.001; <jats:italic>R</jats:italic><jats:sup>2</jats:sup> = 0.427, <jats:italic>P</jats:italic> &lt; 0.001; and <jats:italic>R</jats:italic><jats:sup>2</jats:sup> = 0.340, <jats:italic>P</jats:italic> &lt; 0.001, respectively). Thirty-one surgical patients 6 months post-surgery showed significantly decreased thicknesses (<jats:italic>P</jats:italic> ≤ 0.012) of the foveal INL, inner plexiform layer (IPL), and outer nuclear layer (ONL); the parafoveal retina nerve fiber layer (RNFL), IPL, INL, and ONL; and the perifoveal RNFL, IPL, INL, ganglion cell layer (GCL), outer plexiform layer (OPL), and photoreceptor layer (PRL). We found a weak correlation between postoperative VA and preoperative foveal and perifoveal RNFL thickness (<jats:italic>r</jats:italic> = 0.404 and <jats:italic>r</jats:italic> = 0.359, respectively), and a moderate correlation between postoperative VA and preoperative foveal and parafoveal INL thickness (<jats:italic>r</jats:italic> = 0.529 and <jats:italic>r</jats:italic> = 0.583, respectively) in the 31 surgical patients (<jats:italic>P</jats:italic> ≤ 0.047). The preoperative INL thickness in the foveal, parafoveal, and perifoveal regions showed a moderate to strong correlation (<jats:italic>r</jats:italic> = 0.507, 0.644, and 0.548, respectively), with postoperative VA in patients with ≥ 2 lines of visual improvement (<jats:italic>P</jats:italic> ≤ 0.038).</jats:p> </jats:sec> <jats:sec> <jats:title>Conclusion</jats:title> <jats:p>We detected a correlation between retinal damage and VA in the parafoveal, perifoveal, and foveal regions. Our results suggest that INL thickness in all macular regions may be a prognostic factor for postoperative VA in ERM patients.</jats:p> </jats:sec>

Correlation between tangential distortion of the outer retinal layer and metamorphopsia in patients with epiretinal membrane

“…In that sense, morphological changes in the inner retina may be a useful indicator of the severity of traction force. Notably, the INL thickness was also reported as an indicator of VA in the eyes with ERM [15]. Kim et al reported that the INL thickness was correlated with the degree of metamorphopsia and VA in the same eyes [5].…”

Incidence and risk factors of progressive nasal inner nuclear layer thickening after surgical peeling of epiretinal membrane

“…Previous studies have reported relationship between retinal microstructure and functional visual outcome (such as visual acuity and degree of metamorphopsia) in ERM patients 11 , 13 , 20 , 21 . Especially, structural deformity in INL is known to be significantly related to visual acuity and degree of metamorphopsia 20 , 21 .…”

“…Previous studies have reported relationship between retinal microstructure and functional visual outcome (such as visual acuity and degree of metamorphopsia) in ERM patients 11 , 13 , 20 , 21 . Especially, structural deformity in INL is known to be significantly related to visual acuity and degree of metamorphopsia 20 , 21 . Zou et al 21 revealed that preoperative INL thickness in foveal, parafoveal, and perifoveal region correlates with postoperative improvement of visual acuity in 35 ERM patients.…”

“…Especially, structural deformity in INL is known to be significantly related to visual acuity and degree of metamorphopsia 20 , 21 . Zou et al 21 revealed that preoperative INL thickness in foveal, parafoveal, and perifoveal region correlates with postoperative improvement of visual acuity in 35 ERM patients. Okamoto et al 13 reported that INL thickness had significant correlation with degree of metamorphopsia at each time point in ERM patients after the surgery.…”

Influence of Preoperative Foveal Layers’ Thickness on Visual Function and Macular Morphology by Phacovitrectomy for Epiretinal Membrane

“…As the study by Zou et al has shown, those with SD-OCT (Cirrus; Carl Zeiss Meditec Inc. ® , Dublin, CA, USA) machine-measured foveal IPL, INL, and ONL thickness at ERM 42.25 ± 13.22, 75.56 ± 28.49, and 130.9 ± 22.65 μ m, CFT was 504.93 ± 118.14 μ m [ 22 ]. There was a clear difference between the fovea layers as measured mechanically in the study and manually by us in the ERM both in absolute numbers and in the ratio of the thickness of the individual fovea layers to the CFT.…”