Role of growth factors and internal limiting membrane constituents in müller cell migration

Platelet rich plasma for primary macular hole: A case series

OBJECTIVE

To evaluate the anatomical and functional macular results and rate of complications following surgical treatment of primary macular hole (MH) with autologous platelet rich plasma (a-PRP) use.

DESIGN

retrospective, interventional, non-randomized case series.

PARTECIPANTS AND METHODS

A cohort of 9 consecutive patients from January 1, 2019 to August 31, 2021 who underwent vitrectomy with a-PRP use for primary MH were included. Anatomical results based on spectral domain- optical coherence tomography (SD-OCT) and visual acuity were analyzed.

RESULTS

10 pseudophakic eye of 9 patients were enrolled. Six patients were female and three patients were male. The mean age was 69.9 years ± 1.48. The baseline MH minimum diameter was 486.1 μm ± 37.1, and mean pre operative best-corrected visual acuity (BCVA) was 0.91 ± 0.03 logMAR (Snellen equivalent 20/160). Mean 1 month post operative BCVA was 0.81 ± 0.57 logMAR (Snellen equivalent 20/130; p = 1.000); mean 3 month post operative BCVA was 0.66 ± 0.04 logMAR (Snellen equivalent 20/90; p = 0.006); mean 6 month post operative BCVA was 0.6 ± 0.04 logMAR (Snellen equivalent 20/80; p < 0.001). In all eyes, 10/10 (100%), there was a complete MH closure at 6 months follow up: 5 eyes (50%) with a U-type closure pattern, 4 eyes (40%) with a V-type pattern and 1 eye (10%) with an irregular foveal contour closure at 6 month follow-up. No ocular and systemic complications were reported.

CONCLUSION

The a-PRP use is a successful and promising vitreoretinal surgical technique option for primary MH.

The no-retina-touch technique: vitrectomy and platelet-rich plasma in the treatment of lamellar macular hole. New insights into pathogenesis

PURPOSE

To explore the use of autologous platelet-rich plasma (PRP) as a potential therapeutic adjuvant strategy for treating degenerative lamellar macular holes (LMHs).

DESIGN

A prospective interventional case series.

METHODS

Seven consecutive patients (8 eyes) with a diagnosis of LMH underwent a pars-plana vitrectomy with PRP injection under air tamponade. Anatomical results based on spectral domain optical coherence tomography (SD-OCT) and functional results, in terms of best corrected visual acuity (BCVA) and reading performance, were analyzed.

RESULTS

At 12 months postoperatively, 7 out of 8 eyes (88%) presented a complete closure of the LMH. The ellipsoid zone (EZ) was restored in 3 eyes (37.5%). The mean (±SD) postoperative BCVA was 0.39 (±0.56) LogMAR, resulting in a statistically significant visual acuity improvement (p = 0.007). The mean (±SD) maximum reading speed (MaxRS) improved to 133.48 (±41.47) wpm, with a significant increase compared to the baseline (p = 0.029). The mean (±SD) reading acuity score (RA score) resulted in 0.44 (±0.04) LogRAD, with an improvement in reading acuity that did not reach statistical significance (p = 0.129).

CONCLUSIONS

The utilization of the PRP technique with a no-retina-touch approach safeguards the delicate retinal tissues, minimizing the possibility of iatrogenic trauma or post-operative complications, while maintaining a high rate of efficacy in enabling the improvement of the foveal defect in lamellar macular holes.

Synthesis, Properties, and Biocompatibility of 4-Carboxyphenyboronic Acid-Modified Gelatin-Methacryloyl: A Hydrogel for Retinal Surgeries

The current surgical adjunctive for vitreoretinal surgeries fails to provide an adequate 3D structure for cellular regeneration. A one-pot synthesis of gelatin-methacryloyl (GelMA) followed by modification with 4-carboxyphenylboronic acid (4-CPBA) was performed to fabricate 4-CPBA-modified GelMA (4CPBA@GelMA), a gelatin-based hydrogel. 4CPBA@GelMA was photo-cross-linked by 405 nm violet light and examined using nuclear magnetic resonance (NMR), Fourier-transform infrared spectrometry (FTIR), scanning electron microscopy (SEM), and rheometry. In vitro biocompatibility was examined by Müller cell proliferation assays exposed to 4CPBA@GelMA and violet light. In vivo retinal biocompatibility was evaluated by electroretinography of rat eyes that were exposed to intravitreally injected and photo-cross-linked 4CPBA@GelMA at days 3, 7, 14, and 28 post-injection. Following electroretinography, histology and immunohistochemistry were performed on the retinas. The NMR results indicated amidation of GelMA by 4-CPBA, and FTIR confirmed the presence of the CPBA ring in 4CPBA@GelMA samples. SEM revealed that 4CPBA@GelMA had significantly larger pores than GelMA (56.9 ± 9.5 vs 35.1 ± 2.8 μm; P < 0.001). Rheological findings showed that, unlike GelMA and gelatin, 4CPBA@GelMA has Newtonian fluid properties at room temperature. Exposure to 4CPBA@GelMA did not significantly affect Müller cell viability in a proliferation assay; moreover, electroretinography findings indicated normal waveforms and implicit times, and histology and immunohistochemistry examinations revealed no significant changes. In this study, we established the high retinal compatibility of 4CPBA@GelMA. The low viscosity of 4CPBA@GelMA is ideal for injection via small-gauge needles, and the larger pore size and three-dimensional network both potentiate cellular migration and growth. These features made 4CPBA@GelMA a candidate for vitreoretinal surgical adjunctive that might promote retinal regeneration.

Platelet-rich Fibrin Membrane Transplantation for the Treatment of Highly Myopic Macular Hole Retinal Detachment

INTRODUCTION

Highly myopic macular hole retinal detachment (MHRD) is often associated with a poor prognosis, and there is currently no optimal treatment. Platelet-rich fibrin (PRF), an autologous blood product, has been shown to promote tissue regeneration. This prospective, randomized, controlled study investigated the efficacy of conventional internal limiting membrane (ILM) peeling versus PRF membrane transplantation in highly myopic MHRD.

METHODS

Eyes with highly myopic MHRD were randomly assigned to either a conventional ILM peeling group (IP group, n = 19) or a PRF membrane transplantation group (PMT group, n = 21). The study followed participants for a period of 6 months. The primary outcome measure was macular hole (MH) closure assessed using optical coherence tomography. Secondary outcomes included best-corrected visual acuity (BCVA), central retinal thickness (CRT), superficial vascular density (SVD), deep vascular density (DVD), rate of retinal reattachment, and any complications encountered.

RESULTS

MH closure was achieved in a significantly greater proportion of eyes in the PMT group (21/21, 100.00%) compared to the IP group (15/19, 78.95%) (P = 0.042). Retinal reattachment was accomplished in all patients (100.00%) within both groups. Except for an insignificant difference in BCVA observed at 1 week post-surgery in the IP group, significant improvements in BCVA and CRT were documented in both groups across all other post-operative time points. Final BCVA (P = 0.040), CRT (P = 0.002), SVD (P = 0.002), and DVD (P = 0.013) were all significantly higher in the PMT group compared to the IP group. No serious complications were identified in either group.

CONCLUSIONS

This study demonstrated the superiority of PRF membrane transplantation compared to conventional ILM peeling in promoting MH closure and enhancing retinal vascular density in patients with highly myopic MHRD. Additionally, PRF membrane transplantation effectively restores retinal reattachment, improves visual function, and increases retinal thickness without introducing additional complications.

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Platelet concentrates in macular hole surgery. A journey through the labyrinth of terminology, preparation, and application: a comprehensive review

The surgical management of macular holes is undergoing continuous evolution, with recent focus on the utilization of platelet concentrates as a promising adjunctive intervention. Currently, they present a valid surgical approach for achieving anatomical and functional success with a non-inferiority comparably to the alternative surgical techniques. Nonetheless, the utilization of varied platelet concentrates terminologies, coupled with the lack of standardization in their preparation methodologies, engenders both lexical confusion and challenges in comparing scientific studies published up until now. In this review, we summarized the published evidence concerning the application of platelet concentrates in macular holes surgery, aiming to clarify the terminology and methodologies employed and to establish a common consensus facilitating further development and diffusion of this promising technique.

Comparison of the therapeutic effects of lens capsular flap transplantation and autologous retinal transplantation in the management of refractory macular holes

PURPOSE

To report the comparison of the therapeutic effects of lens capsular flap transplantation (LCT) and autologous retinal transplantation (ART) in refractory macular hole (MH) treatment.

METHODS

Thirty-one patients (31 eyes) with refractory MH were retrospectively reviewed. The patients were divided into two groups based on the surgical procedures: the LCT group (13 eyes) and the ART group (18 eyes). Patients were monitored for a minimum of 6 months. Best corrected visual acuity (BCVA), hole closure rate, postoperative central foveolar thickness (CFT), and some complications (e.g. graft loss or dislocation, postoperative retinal detachment, or postoperatively elevated intraocular pressure) were the primary outcome measures.

RESULTS

The mean preoperative MH diameter was 1104 ± 287 μm in the LCT group and 1066 ± 297 μm in the ART group (t = 0.353, P = 0.727). The MH was closed in 12 patients (92.3%) of the LCT group and 17 patients (94.4%) of the ART group (χ2 = 0.057, P = 0.811); the MHs of 10 patients (76.9%) in the LCT group and 11 patients (61.1%) in the ART group were completely closed (χ2 = 0.864, P = 0.353). The BCVA improved from 2.3 ± 1.0 logMAR preoperatively to 1.3 ± 0.9 logMAR postoperatively in the LCT group and 2.3 ± 0.9 logMAR preoperatively to 1.0 ± 0.6 logMAR postoperatively in the ART group (postoperative BCVA vs preoperative BCVA in the LCT group: t = 4.374, P = 0.001; postoperative BCVA vs preoperative BCVA in the ART group: t = 5.899, P = 0.000018). The visual improvement was 1.3 ± 0.9 logMAR in the ART group and 1.0 ± 0.8 logMAR in the LCT group (t = - 1.033, P = 0.310). The postoperative CFT was 139.7 ± 48.3 μm in the LCT and 199.2 ± 25.1 μm in the ART group (t = - 4.062, P = 0.001). Graft dislocation emerged in 2 patients (15.4%) in the LCT group and 1 patient (5.6%) in the ART group.

CONCLUSIONS

Applications of LCT and ART may both enhance anatomical and visual outcomes in refractory MH cases. The ART group exhibited a more optimal postoperative CFT than the LCT group one.

Comparison of the effects of EGF, FGF-b, and NGF on the proliferation, migration, and reprogramming of primary rat Müller cells

Purpose

During the healing process of full-thickness macular holes (FTMHs), the closure and recovery of the hole depend on the migration, proliferation, and activation of Müller cells to promote the closure of holes and restoration of the photosensitive layer. In this study, we investigated the ability of the epidermal growth factor (EGF), fibroblast growth factor-basic (FGF-b), and nerve growth factor (NGF) to influence this process by regulating proliferation, migration, and reprogramming of primary rat Müller cells.

Methods

Cell proliferation was measured using CCK8 [2- (2-Methoxy-4-nitrophenyl)-3- (4-nitrophenyl)-5- (2,4-disulfophenyl)-2H-tetrazolium Sodium Salt] colorimetric assays and EdU [5-Ethynyl-2'-deoxyuridine] assays over 48 h. Cell migration was measured using scratch-wound assays and transwell migration assays over 48 h. In addition, we conducted Western blot assays and immunofluorescence assays on cells that were specially treated for 1, 3, and 5 days for cell reprogramming. The percentage of EdU-positive cells in Nestin-positive have also been tested by co-immunofluorescence (Co-IF) staining.

Results

EGF and FGF-b significantly promoted the proliferation of Müller cells (p < 0.05) at a concentration of 0-50 ng/mL, but NGF did not (p > 0.05), compared to untreated controls. Exogenous FGF-b and EGF promote the reprogramming of primary rat Müller cells, significantly enhancing the neural stem cell marker Nestin after stimulation on the 1st, 3rd, and 5th days, respectively. The expression of Müller cell marker Vimentin was significantly (p < 0.05) reduced during this period compared to the control group. However, there was no significant difference between the NGF and control groups. Furthermore, the EGF group expressed stronger Nestin expression than the SCM group. The Co-IF staining showed that early 50% of activated cells came from newly proliferating cells on the 5th day.

Conclusion

These observations suggest that FGF-b can promote the activation of Müller cells in a short time and enhance the possessive features of neural stem cells, while EGF may act for a longer period of time. This may further the understanding of growth factor therapy in treating FTMHs, and Müller glia may be promising candidates for cell replacement therapy.

Inhibition of Rho kinase (ROCK) impairs cytoskeletal contractility in human Müller glial cells without effects on cell viability, migration, and extracellular matrix production

The epiretinal membrane is a fibrocontractile tissue that forms on the inner surface of the retina, causing visual impairment ranging from mild to severe, and even retinal detachment. Müller glial cells actively participate in the formation of this membrane. Current research is constantly seeking for new therapeutic approaches that aim to prevent or treat cellular dysfunctions involved in the progression of this common fibrosis condition. The Rho GTPases signaling pathway regulates several processes associated with the epiretinal membrane, such as cell proliferation, migration, and contraction. Rho kinase (ROCK), an effector of the RhoA GTPase, is an interesting potential therapeutic target. This study aimed to evaluate the effects of a ROCK inhibitor (Y27632) on human Müller cells viability, growth, cytoskeletal organization, expression of extracellular matrix components, myofibroblast differentiation, migration, and contractility. Müller cells of the MIO-M1 lineage were cultured and treated for different periods with the inhibitor. Viability was evaluated by MTT assay and trypan blue exclusion method, and growth was evaluated by growth curve and BrdU incorporation assay. The actin cytoskeleton was stained with fluorescent phalloidin, intermediate filaments and microtubules were analyzed with immunofluorescence for vimentin and α-tubulin. Gene and protein expression of collagens I and V, laminin and fibronectin were evaluated by rt-PCR and immunofluorescence. Chemotactic and spontaneous cell migration were studied by transwell assay and time-lapse observation of live cells, respectively. Cell contractility was assessed by collagen gel contraction assay. The results showed that ROCK inhibition by Y27632 did not affect cell viability, but decreased cell growth and proliferation after 72 h. There was a change in cell morphology and organization of F-actin, with a reduction in the cell body, disappearance of stress fibers and formation of long, branched cell extensions. Microtubules and vimentin filaments were also affected, possibly because of F-actin alterations. The inhibitor also reduced gene expression and immunoreactivity of smooth muscle α-actin, a marker of myofibroblasts. The expression of extracellular matrix components was not affected by the inhibitor. Chemotactic cell migration showed no significant changes, while cell contractility was substantially reduced. No spontaneous migration of MIO-M1 cells was observed. In conclusion, pharmacological inhibition of ROCK in Müller cells could be a potentially promising approach to treat epiretinal membranes by preventing cell proliferation, contractility and transdifferentiation, without affecting cell viability.

MicroRNA-152-3p and MicroRNA-196a-5p Are Downregulated When Müller Cells Are Promoted by Components of the Internal Limiting Membrane: Implications for Macular Hole Healing

Müller cells play a critical role in the closure of macular holes, and their proliferation and migration are facilitated by the internal limiting membrane (ILM). Despite the importance of this process, the underlying molecular mechanism remains underexplored. This study investigated the effects of ILM components on the microRNA (miRNA) profile of Müller cells. Rat Müller cells (rMC-1) were cultured with a culture insert and varying concentrations of ILM component coatings, namely, collagen IV, laminin, and fibronectin, and cell migration was assessed by measuring cell-free areas in successive photographs following insert removal. MiRNAs were then extracted from these cells and analyzed. Mimics and inhibitors of miRNA candidates were transfected into Müller cells, and a cell migration assay and additional cell viability assays were performed. The results revealed that the ILM components promoted Müller cell migration (p < 0.01). Among the miRNA candidates, miR-194-3p was upregulated, whereas miR-125b-1-3p, miR-132-3p, miR-146b-5p, miR-152-3p, miR-196a-5p, miR-542-5p, miR-871-3p, miR-1839-5p, and miR-3573-3p were significantly downregulated (p < 0.05; fold change > 1.5). Moreover, miR-152-3p and miR-196a-5p reduced cell migration (p < 0.05) and proliferation (p < 0.001), and their suppressive effects were reversed by their respective inhibitors. In conclusion, miRNAs were regulated in ILM component-activated Müller cells, with miR-152-3p and miR-196a-5p regulating Müller cell migration and proliferation. These results serve as a basis for understanding the molecular healing process of macular holes and identifying potential new target genes in future research.

The Short-Term Results of Autologous Platelet-Rich Plasma as an Adjuvant to Re-Intervention in the Treatment of Refractory Full-Thickness Macular Holes

The purpose of this study was to investigate the short-term efficacy and safety of autologous platelet-rich plasma (a-PRP) as an adjuvant to revisional vitrectomy for refractory full-thickness macular holes (rFTMHs). We conducted a prospective, non-randomized interventional study including patients with rFTMH after a pars plana vitrectomy (PPV) with internal limiting membrane peeling and gas tamponade. We included 28 eyes from 27 patients with rFTMHs: 12 rFTMHs in highly myopic eyes (axial length greater than 26.5 mm or a refractive error greater than -6D or both); 12 large rFTMHs (minimum hole width > 400 μm); and 4 rFTMHs secondary to the optic disc pit. All patients underwent 25-G PPV with a-PRP, a median time of 3.5 ± 1.8 months after the primary repair. At the six-month follow-up, the overall rFTMH closure rate was 92.9%, distributed as follows: 11 out of 12 eyes (91.7%) in the highly myopic group, 11 out of 12 eyes (91.7%) in the large rFTMH group, and 4 out of 4 eyes (100%) in the optic disc pit group. Median best-corrected visual acuity significantly improved in all groups, in particular from 1.00 (interquartile range: 0.85 to 1.30) to 0.70 (0.40 to 0.85) LogMAR in the highly myopic group (p = 0.016), from 0.90 (0.70 to 1.49) to 0.40 (0.35 to 0.70) LogMAR in the large rFTMH group (p = 0.005), and from 0.90 (0.75 to 1.00) to 0.50 (0.28 to 0.65) LogMAR in the optic disc pit group. No intraoperative or postoperative complications were reported. In conclusion, a-PRP can be an effective adjuvant to PPV in the management of rFTMHs.

Long-Term Results of Adjunct Autologous Platelet-Rich Plasma in Lamellar Macular Hole Surgery Showing Lasting Restoration of Foveal Anatomy

The aim of this study was to evaluate the long-time results of highly concentrated autologous platelet-rich plasma (PRP) used as an adjunct in lamellar macular hole (LMH) surgery. Nineteen eyes of nineteen patients with progressive LMH were enrolled in this interventional case series, on which 23/25-gauge pars plana vitrectomy was performed and 0.1 mL of highly concentrated autologous platelet-rich plasma was applied under air tamponade. Posterior vitreous detachment was induced, and the peeling of tractive epiretinal membranes, whenever present, was performed. In cases of phakic lens status, combined surgery was carried out. Postoperatively, all patients were instructed to remain in a supine position for the first two postoperative hours. Best-corrected visual acuity (BCVA) testing, microperimetry, and spectral domain optical coherence tomography (SD-OCT) were carried out preoperatively and at minimum 6 months (in median 12 months) postoperatively. Foveal configuration was postoperatively restored in 19 of 19 patients. Two patients who had not undergone ILM peeling showed a recurring defect at 6-month follow-up. Best-corrected visual acuity improved significantly from 0.29 ± 0.08 to 0.14 ± 0.13 logMAR (p = 0.028, Wilcoxon signed-rank test). Microperimetry remained unchanged (23.38 ± 2.53 preoperatively; 23.0 ± 2.49 dB postoperatively; p = 0.67). No patients experienced vision loss after surgery, and no significant intra- or postoperative complications were observed. Using PRP as an adjunct in macular hole surgery significantly improves morphological and functional outcomes. Additionally, it might be an effective prophylaxis to further progression and also the formation of a secondary full-thickness macular hole. The results of this study might contribute to a paradigm shift in macular hole surgery towards early intervention.

EXCESSIVE GLIOSIS AFTER VITRECTOMY FOR THE HIGHLY MYOPIC MACULAR HOLE: A Spectral Domain Optical Coherence Tomography Study

PURPOSE

To investigate different modes of foveal regeneration after the closure of idiopathic macular hole (IMH) or highly myopic macular hole (HMMH) by vitrectomy with internal limiting membranes peeling or flap techniques.

METHODS

This retrospective observational study followed 47 IMH and 50 HMMH eyes for at least 6 months. Twenty four IMH and 25 HMMH eyes underwent internal limiting membrane peeling, whereas 23 IMH and 25 HMMH eyes received inverted internal limiting membrane flap technique. Spectral domain optical coherence tomography was used to analyze macular hole closure, foveal microstructures, and excessive gliosis as a foveal "peak-like" protuberance.

RESULTS

A single procedure closed all IMH (n = 47). For HMMH, the inverted group (n = 25, 100%) closed more macular hole than the peeling group (n = 14, 56.00%) (P < 0.001). Excessive gliosis only occurred in the inverted group, and there was a significant difference (P = 0.005) in incidence between IMH (three in 23 eyes, 13.04%) and HMMH (13 in 25 eyes, 52.00%). The axial length more than 29.985 mm enhanced the risk of excessive gliosis.

CONCLUSION

The inverted internal limiting membrane flap efficiently treated refractory MHs but was prone to cause excessive gliosis in highly myopic eyes. Excessive elongation of the globe (axial length > 29.985 mm) was linked to excessive gliosis growth.

Semaphorin 3A Inhibits Endoplasmic Reticulum Stress Induced by High Glucose in Müller Cells

PURPOSE

This study aimed to explore the effect of the Semaphorin3A (Sema3A)/Neuropilin-1 (Nrp-1) pathway on Müller cell activities and endoplasmic reticulum (ER) stress induced by high glucose (HG) in vitro.

METHODS

The primary Müller cells of C57BL/6J mice were isolated and cultured in normal or high glucose medium. The expression of endogenous Sema3A and its coreceptor Nrp-1 was measured by Western blot. Müller cells were incubated with exogenous recombinant Sema3A protein or transfected with lentiviral vectors expressing small hairpin RNA (shRNA) to knock down the expression of endogenous Sema3A. The proliferation of Müller cells was detected by CCK-8 assay and EdU staining. The migratory ability was detected by the Transwell migration assay. The level of endoplasmic reticulum (ER) stress was analyzed through the detection of GRP78/BiP, IRE1α, phosphorylated IRE1αS724 (p-IRE1αS724), and the splicing rate of XBP1 (XBP1s/XBP1) by using immunofluorescence, Western blot or quantitative polymerase chain reaction (qPCR).

RESULTS

HG induced the upregulation of endogenous Sema3A and Nrp-1 receptors in Müller cells. The expression of GRP78/BiP and IRE1α was upregulated by HG, with an increased splicing rate of XBP1. Exogenous Sema3A inhibited HG-induced Müller cell proliferation, migration, and GRP78/BiP-IRE1α-XBP1 axis activation. Knockdown of Sema3A promoted proliferation, migration, and ER stress induced by high glucose in Müller cells.

CONCLUSION

Sema3A inhibited the increased proliferative and migratory activities induced by high glucose by attenuating ER stress in Müller cells.

Intraoperative Optical Coherence Tomography in the Management of Macular Holes: State of the Art and Future Perspectives

BACKGROUND

Non-invasive diagnostic technologies in ophthalmology have substantially transformed contemporary clinical practice. Intraoperative optical coherence tomography (iOCT) systems have recently been used for various surgical interventions, including the treatment of full-thickness macular holes (FTMHs).

MATERIALS AND METHODS

We conducted a systematic review on the use of iOCT and its possible benefits in the management of FTMHs, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA). The level of evidence according to the Oxford Centre for Evidence-Based Medicine (OCEM) 2011 guidelines, and the quality of evidence according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system, were assessed for all included articles.

RESULTS

1131 articles were initially extracted, out of which 694 articles were obtained after duplicates were removed and their abstracts screened. A total of 65 articles was included for full-text review. Finally, 17 articles remained that fulfilled the inclusion criteria.

CONCLUSIONS

Even though there is just a small number of studies with solid results, the use of iOCT in FTMH surgery may be a helpful tool for both novice and experienced surgeons planning and managing difficult cases. Additionally, it could be used for teaching reasons and for exploring novel surgical techniques.

Single-Layer Inverted Internal Limiting Membrane Flap Versus Conventional Peel for Small- or Medium-Sized Full-Thickness Macular Holes

PURPOSE

To analyze the outcomes of using an internal limiting membrane (ILM) flap and the conventional ILM peel technique for small- or medium-sized full-thickness macular hole (FTMH) repair.

DESIGN

Retrospective, interventional case series.

METHODS

Eyes with an FTMH ≤400 µm that underwent vitrectomy with a single-layer inverted ILM flap (flap group, 55 eyes) or an ILM peel (peel group, 62 eyes) were enrolled. Best-corrected visual acuity (BCVA) and optical coherence tomography (OCT) measurements were obtained preoperatively and at 1, 3, 6, and 12 months postoperatively.

RESULTS

Primary hole closure was achieved in 54 (98%) and 60 (97%) eyes in the flap and peel groups, respectively. The preoperative and postoperative 12-month BCVA values were comparable between the groups but were significantly better in the flap than in the peel group at 1 month (mean ± SD logMAR: 0.83 ± 0.43 vs 1.14 ± 0.50; P = .001), 3 months (0.58 ± 0.33 vs 0.82 ± 0.43; P = .002), and 6 months (0.56 ± 0.32 vs. 0.72 ± 0.48; P = .028). In the flap group, foveal gliosis was less common than in the peel group at 1 month (P = .030), and restored external limiting membrane and interdigitation zone was more common at 3 months (P = .046 and P < .001, respectively).

CONCLUSIONS

The single-layer ILM flap and conventional ILM peel techniques both closed FTMHs and improved vision. ILM flaps were associated with better visual outcomes up to 6 months postoperatively and should be considered in FTMHs ≤400 µm.

Visual improvement and regeneration of retinal layers in eyes with small, medium, and large idiopathic full-thickness macular holes treated with the inverted internal limiting membrane flap technique over a period of 12 months

PURPOSE

This study aims to compare the improvement of best-corrected visual acuity (BCVA) and the reduction in defect length of external limiting membrane (ELM) and ellipsoid zone (EZ) in small ([Formula: see text] 250 μm), medium ([Formula: see text] 250 μm), and large ([Formula: see text] 400 μm) full-thickness macular holes (FTMH) treated with inverted internal limiting membrane (I-ILM) flap technique over a follow-up period of 12 months.

METHODS

Ninety-one eyes of 87 patients were enrolled in this retrospective study. BCVA and spectral-domain optical coherence tomography (SD-OCT) were conducted preoperatively as well as after 1, 3, 6, 9, and 12 months postoperatively. The defect length of the ELM and the EZ was measured using the caliper tool at each follow-up time point.

RESULTS

BCVA improved significantly in the group of small, medium, and large FTMH over the time of 12 months, whereby the improvement did not depend on FTMH size over 9 months. Only after 12 months, large FTMH showed significantly higher BCVA improvement compared to small and medium FTMH. The closure rate was 100% (91/91). The defect length of ELM and EZ reduced continuously over the period of 12 months. There was a significant correlation between defect length of ELM and EZ with postoperative BCVA.

CONCLUSION

The I-ILM flap technique has very good morphological and functional outcomes in small, medium, and large FTMH over a long-time period, indicating that it can be considered as a treatment option in small and medium FTMH. The defect length of ELM and EZ is directly connected to postoperative BCVA.

Intraoperative Observation of a Macular Holes Using Optical Coherence Tomography

PURPOSE

This study aimed to observe intraoperative changes in macular hole (MH) form using intraoperative optical coherence tomography (iOCT).

METHODS

A total of 10 eyes from 10 patients with MH who underwent vitrectomy using iOCT from May 2015 to October 2015 at the Yamagata University Hospital were retrospectively evaluated. Accordingly, 25-gauge pars plana vitrectomy using iOCT with internal limiting membrane (ILM) peeling and sulfur hexafluoride gas tamponade was performed on each patient. During surgery, MHs were observed using iOCT over four points, namely, before posterior vitreous detachment (PVD) formation, after PVD formation, after ILM peeling, and after fluid-gas exchange. Thereafter, basal MH diameter and minimum aperture MH diameter were postoperatively analyzed.

RESULTS

Before PVD formation, after PVD formation, after ILM peeling, and after fluid-gas exchange, the mean basal MH diameters were 690.7 ± 268.4, 683.3 ± 274.2, 683.7 ± 269.5, and 668.3 ± 261.4 μm, while the mean minimum aperture MH diameters were 278.3 ± 165.2, 283.0 ± 170.2, 257.0 ± 127.8, and 188.0 ± 105.0 μm, respectively. The mean minimum aperture MH diameter decreased significantly after fluid-gas exchange (one-way repeated measures ANOVA, p < 0.05). None of the patients exhibited intraoperative closure of the MHs. However, MH closure was confirmed in all patients after the surgery.

CONCLUSION

None of the patients demonstrated intraoperative MHs closure. Accordingly, the minimum aperture MH diameter was the first change formation to close after fluid-gas exchange.