Reproducibility of each retinal layer thickness measurement in epiretinal membrane patients with ectopic inner foveal layers

BACKGROUND

To identify the reliability of each retinal layer thickness measurement in epiretinal membrane (ERM) patients with ectopic inner foveal layers (EIFLs).

METHODS

Subjects were divided into two groups: ERM patients with EIFLs (Group 1) and without EIFLs (Group 2). The retinal layer thickness was measured twice, and intraclass correlation coefficient (ICC) and coefficient of variation (CV) values were calculated.

RESULTS

In Group 1, the CVs of the nerve fiber layer (NFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), and outer nuclear layer (ONL) were 22.39%, 13.12%, 13.37%, 13.21%, 15.09%, and 11.94%, while the ICCs were 0.431, 0.550, 0.440, 0.286, 0.279, and 0.503, respectively. In Group 2, the CVs were 18.20%, 10.59%, 10.65%, 13.27%, 14.75%, and 10.37%, while the ICCs were 0.788, 0.834, 0.830, 0.715, 0.226, and 0.439, respectively. The average central macular thickness (CMT) was significantly correlated with the CVs of NFL (coefficient = 0.317; P < 0.001), GCL (coefficient = 0.328; P < 0.001), and IPL (coefficient = 0.186; P = 0.042) in Group 1.

CONCLUSIONS

The reproducibility of the inner retinal layer thickness measurements in ERM patients with EIFLs was low compared to those without EIFLs. The reproducibility of the outer retinal layer thickness measurements, including OPL and ONL, was poor regardless of the presence of EIFLs in ERM patients. Additionally, the thicker the CMT in patients with EIFLs, the lower the reproducibility of the inner retinal layer thickness measurements.

Tight adherent feature on optical coherence tomography predict postoperative visual outcome in epiretinal membrane eyes

Background

To identify the predictive parameter among preoperative measurements that best predicts postoperative visual outcome in the epiretinal membrane (ERM).

Methods

Thirty-three consecutive patients with idiopathic unilateral ERM patients between 2015 and 2018 were enrolled. Nineteen healthy normal eyes were selected as an independent age-matched group. Based on preoperative optical coherence tomography (OCT), we further divided the patients with ERM into two groups: type 1, loosely attached ERM, and type 2, tight adherent ERM. We documented the vision and thickness of various retinal layers: nerve fiber layer, ganglion cell layer, inner plexiform layer (GCL + IPL), inner nuclear layer (INL), outer retinal layer (ORL), and retinal pigment epithelium/Bruch complex layer before and after the surgery. The association between postoperative visual acuity and these variables was analyzed using multiple linear regression analysis.

Results

All retinal layers of ERM eyes were thicker than the normal eyes (P < 0.05). Among ERMs, we identified 11 eyes with type 1 adhesions and 22 eyes with type 2 adhesions. The preoperative GCL + IPL layers were significantly thicker in type 2 patients than in type 1 patients (93.67 ± 33.03 um vs 167.71 ± 13.77 um; P = 0.023). Greater GCL + IPL thickness was correlated with a worse postoperative visual acuity and multiple linear regression analysis showed that GCL + IPL thickness was an independent predictor of postoperative visual acuity (VA) (beta value = 0.689; P = 0.012). A greater thickness of GCL + IPL layers of type 2 patients had worse postoperative best-corrected visual acuity (BCVA) (P = 0.028). Ectopic inner foveal layers with disappearance of fovea pit were persistently presented in OCT profiles of both groups.

Conclusion

Idiopathic ERM demonstrated significantly thicker inner retinal layers (GCL + IPL and INL). However, the ORL thickness was similar between the normal eyes and ERM eyes. The preoperative GCL + IPL layers were significantly thicker in patients with type 2 ERM than that in patients with type 1 ERM. The increase in GCL + IPL thickness was significantly correlated with worse postoperative visual outcomes.

Inner retinal layers' alterations and microvasculature changes after vitrectomy for rhegmatogenous retinal detachment

PURPOSE

To examine the retinal layers' changes and alterations in retinal microvasculature in patients with rhegmatogenous retinal detachment (RRD) treated with pars plana vitrectomy (PPV).

METHODS

Participants in this study were 103 patients with RRD, 85 macula off and 18 macula on, who were treated with PPV and gas tamponade without internal limiting membrane peeling, in two centers. All participants underwent best corrected visual acuity measurement, slit-lamp examination, fundoscopy, spectral domain-optical coherence tomography and optical coherence tomography angiography at week 5 and at month 6 postoperatively. The fellow untreated eyes were also examined and served as control data.

RESULTS

A statistically significant enlargement in foveal avascular zone (FAZ) in both superficial capillary plexus (SCP) and deep capillary plexus (DCP) was noticed 5 weeks postoperatively in patients with RRD treated with PPV compared to the fellow eyes and remained 6 months after surgery. The FAZ enlargement in the operated eyes was accompanied with a statistically significant thinning of the inner retinal layer. In addition, there was a significant decrease in foveal and parafoveal vessel density (VD) in both SCP and DCP in the operated eyes compared to control eyes at week 5 postoperatively, which also remained at postoperative month 6.

CONCLUSIONS

The study demonstrated that patients with RRD treated with PPV presented changes in the retinal microvasculature in both SCP and DCP, including enlargement of FAZ and decrease in VD. These changes seemed to be associated with inner retinal layer thinning.