Incidence and quantitative analysis of dissociated optic nerve fiber layer appearance: real loss of retinal nerve fiber layer?

Adipose-derived stem cell exosomes ameliorate traumatic brain injury through the NLRP3 signaling pathway

The exosomes of mesenchymal stem cells have immunoregulatory properties and can effectively mitigate secondary neuroinflammation due to traumatic brain injury (TBI). In this study, we found that adipose-derived stem cell exosomes (ADSCs-Exo) could reduce the inflammatory response after traumatic brain injury by reducing NLRP3 inflammasome secretion by microglial. ADSCs-Exo were monitored by Western blot and electron microscopy. An in-vitro lipopolysaccharide (LPS)-caused primary microglia model and a TBI rat model were constructed. Functional recovery was examined using the modified neurological severity score and foot fault tests. Inflammasome inactivation in LPS-stimulated microglial, ADSCs-Exo can reduce the secretion of interleukin (IL)-1β, IL-6 and tumor necrosis factor α. Compared with PBS-processed controls, the sensorimotor functional recovery was significantly improved by exosome treatment after injury at 14-35 days. Additionally, NLRP3 inflammasome was stimulated within 24 h after TBI. ADSCs-Exo application led to remarkable down-expression of NLRP3 and caspase-1. ADSCs-Exo can ameliorate LPS-induced inflammatory activation by reducing microglial pro-inflammatory cytokines. Moreover, the neuroprotective effect of ADSCs-Exo may be partially attributed to the inhibition thereof on the formation of NLRP3-mediated inflammasome. Such findings imply a potential function of ADSCs-Exo in treating TBI.

Analysis of Retinal Microstructure in Eyes with Dissociated Optic Nerve Fiber Layer (DONFL) Appearance following Idiopathic Macular Hole Surgery: An Optical Coherence Tomography Study

(1) Purpose: This study aimed to evaluate morphological changes of the retina in eyes with dissociated optic nerve fiber layer (DONFL) appearance following internal limiting membrane (ILM) peeling for full-thickness idiopathic macular hole (IMH) on spectral-domain optical coherence tomography (SD-OCT). (2) Methods: We retrospectively analyzed 39 eyes of 39 patients with type 1 macular hole closure after a vitrectomy with ILM peeling procedure at a six-month minimum postoperative follow-up. The retinal thickness maps and cross-sectional OCT images were obtained from a clinical OCT device. The cross-sectional area of the retinal nerve fiber layer (RNFL) on cross-sectional OCT images was manually measured by ImageJ software. (3) Results: The inner retinal layers (IRLs) thickness thinned down much more in the temporal quadrant than in nasal quadrants at 2 and 6 months postoperatively (p < 0.001). However, the cross-sectional area of the RNFL did not change significantly at 2 and 6 months postoperatively (p > 0.05) when compared to preoperative data. In addition, the thinning of the IRL did not correlate with the best-corrected visual acuity (BCVA) at 6 months postoperatively. (4) Conclusions: The thickness of the IRL decreased in eyes with a DONFL appearance after ILM peeling for IMH. The thickness of the IRL decreased more in the temporal retina than in the nasal retina, but the change did not affect BCVA during the 6 months after surgery.

Long-term follow-up of retinal sensitivity assessed by microperimetry in patients with internal limiting membrane peeling

PURPOSE

To evaluate anatomical and functional changes in patients with vitreomacular interface disease after internal limiting membrane (ILM) peeling, using microperimetry along with usual clinical and multimodal retinal imaging.

METHODS

Patients with vitreomacular interface disease requiring vitrectomy underwent multimodal retinal evaluation, including visual acuity assessment, fundus color photograph, Spectral-Domain Optical Coherence Tomography, Optical Coherence Tomography-Angiography, and microperimetry. They were examined at baseline (M0), 6 months (M6) and 18 months (M18) after surgery. Retinal sensitivity was subdivided into three concentric polygons: Large, Medium, Small.

RESULTS

Eleven eyes of 11 patients were analyzed, including 10 epiretinal membranes (ERMs). Best-corrected visual acuity (BCVA) improved in all patients from 0.51 logarithm of the minimal angle of resolution (logMAR) to 0.067 (p = 0.0074). Retinal sensitivity improved between M0 and M6 in all polygons and continued to improve between M6 and M18 for polygons Medium (M) and Small (S) with no statistical significance. At M18, BCVA and retinal sensitivity were similar in the operated eye compared with the fellow eye for all patients. Dissociated optic nerve fiber layer appearance was observed in 8 patients at M18. It was not correlated with either retinal sensitivity or BCVA or microscotomas. No recurrence of ERM or macular hole occurred during follow-up.

CONCLUSION

After surgery, the retinal sensitivity assessed by microperimetry gradually improved until the 18th month and was not different from the values of the fellow eye. These results seemed to confirm that ILM peeling can be an effective and safe technique to treat patients with vitreomacular interface disease.

Prognostic factors of idiopathic epiretinal membrane surgery and evolution of alterations of the central cone bouquet

PURPOSE

To describe the structural changes observed postoperatively in epiretinal membranes (ERM), in particular the alterations in the central cone bouquet (CB), and to identify prognostic factors that might predict postoperative outcome.

METHODS

We included 125 eyes of 117 patients who underwent idiopathic ERM removal with at least a 6-month follow-up. For each patient, spectral-domain optical coherence tomography (SD-OCT) was performed and best-corrected visual acuity (BCVA) was measured, before and after surgery.

RESULTS

Before surgery, 44 eyes (35.2%) presented CB alterations: 65.9% a cotton ball sign, 15.9% a foveolar detachment and 18.2% a pseudovitelliform lesion. Median BCVA increased from 20/63 to 20/32 post-operatively (p = .001) with a mean follow-up of 17 months. The disappearance of CB alterations after surgery was observed in 97.7% of eyes. In stage 3 and 4 ERM, ectopic inner foveal layers persisted in 76.7% of eyes after surgery. Postoperative BCVA was correlated with change in central macular thickness and initial BCVA and was not correlated with the presence of preoperative CB alteration, the initial stage of ERM, the presence of postoperative dissociated optical nerve fiber layer, and the disappearance of ectopic inner fiber layers. The combination of cataract surgery and capsulotomy did not seem to change visual outcome and seemed to accelerate visual recovery. Incidentally, general anesthesia was correlated with final BCVA.

CONCLUSION

ERM surgery allowed a significant gain in BCVA and the disappearance of CB alterations in the great majority of cases. CB alteration did not show to be associated with poor visual prognosis.

Involvement of Anoikis in Dissociated Optic Nerve Fiber Layer Appearance

Dissociated optic nerve fiber layer (DONFL) appearance is characterized by dimpling of the fundus when observed after vitrectomy with the internal limiting membrane (ILM) peeling in macular diseases. However, the cause of DONFL remains largely unknown. Optical coherence tomography (OCT) findings have indicated that the nerve fiber layer (NFL) and ganglion cells are likely to have been damaged in patients with DONFL appearance. Since DONFL appearance occurs at a certain postoperative period, it is unlikely to be retinal damage directly caused by ILM peeling because apoptosis occurs at a certain period after tissue damage and/or injury. However, it may be due to ILM peeling-induced apoptosis in the retinal tissue. Anoikis is a type of apoptosis that occurs in anchorage-dependent cells upon detachment of those cells from the surrounding extracellular matrix (i.e., the loss of cell anchorage). The anoikis-related proteins βA3/A1 crystallin and E-cadherin are reportedly expressed in retinal ganglion cells. Thus, we theorize that one possible cause of DONFL appearance is ILM peeling-induced anoikis in retinal ganglion cells.

Vitrectomy for the removal of idiopathic epiretinal membrane with or without internal limiting membrane peeling: a meta-analysis

Purpose:

The aim of this study is to analyze the effect of internal limiting membrane peeling in removal of idiopathic epiretinal membranes through meta-analysis.

Methods:

We searched PubMed for studies published until 30 April 2018. Inclusion criteria included cases of idiopathic epiretinal membranes, treated with vitrectomy with or without internal limiting membrane peeling. Exclusion criteria consisted of coexisting retinal pathologies and use of indocyanine green to stain the internal limiting membrane. Sixteen studies were included in our meta-analysis. We compared the results of surgical removal of epiretinal membrane, with or without internal limiting membrane peeling, in terms of best-corrected visual acuity and anatomical restoration of the macula (central foveal thickness). Studies or subgroups of patients who had indocyanine green used as an internal limiting membrane stain were excluded from the study, due to evidence of its toxicity to the retina.

Results:

Regarding best-corrected visual acuity levels, the overall mean difference was –0.29 (95% confidence interval: –0.319 to –0.261), while for patients with internal limiting membrane peeling was –0.289 (95% confidence interval: –0.334 to –0.244) and for patients without internal limiting membrane peeling was –0.282 (95% confidence interval: –0.34 to –0.225). Regarding central foveal thickness levels, the overall mean difference was –117.22 (95% confidence interval: –136.70 to –97.74), while for patients with internal limiting membrane peeling was –121.08 (95% confidence interval: –151.12 to –91.03) and for patients without internal limiting membrane peeling was –105.34 (95% confidence interval: –119.47 to –96.21).

Conclusion:

Vitrectomy for the removal of epiretinal membrane combined with internal limiting membrane peeling is an effective method for the treatment of patients with idiopathic epiretinal membrane.

[Macular pucker surgery with and without delamination of the internal limiting membrane-a prospective randomized study]

BACKGROUND

There is evidence that additional internal limiting membrane (ILM) removal reduces the recurrence rate after pucker surgery with a similar functional outcome. On the other hand, morphological changes of the inner retinal layers after ILM peeling have been described. The aim of this study was to compare the long-term data after vitrectomy with and without ILM delamination in order to uncover possible differences in morphological and functional results.

METHODS

In a prospective study of 32 patients with idiopathic epiretinal membrane, 16 patients were randomized into each of 2 groups. Both groups underwent pars plana vitrectomy (ppV) with peeling of the epiretinal membrane. In group 1 no forced additional peeling of the ILM was performed and in group 2 the ILM or ILM residues were additionally removed after staining. The investigated parameters were visual acuity, central retinal thickness (CRT) in optical coherence tomography (OCT), metamorphopsia and surgical complications. The time points of the examinations were directly preoperative, after 1, 3 and 6 months and partly 8.4 years postoperatively.

RESULTS

In group 1 (n = 15) the preoperative mean visual acuity improved from 0.54 logMAR to 0.38 logMAR after 6 months postoperatively (n = 13). Of this group 6 patients could be examined in the long-term course and the visual acuity improved further to 0.32 logMAR after 8 years. The CRT decreased from 473 µm preoperatively to 235 µm in the long-term interval. In group 2 (n = 15) the mean visual acuity preoperatively was 0.47 logMAR and improved 6 months postoperatively (n = 13) to 0.38 logMAR and in the long-term examination (n = 5) to 0.1 logMAR. The CRT in this group decreased from 417 µm preoperatively to 278 µm in the long-term interval. In group 1 one recurrence occurred in the follow-up period, in group 2 none.

CONCLUSION

The study showed that there was no significant difference in visual acuity and CRT between the two groups neither after 6 months nor after 8 years of follow-up. The observed recurrence in the group without ILM delamination underlines the assumption that additional ILM peeling could reduce the recurrence rate.