Accuracy of biomicroscopy, ultrasonography and spectral-domain OCT in detection of complete posterior vitreous detachment.

BACKGROUND: To evaluate the accuracy of preoperative biomicroscopy (BM), ultrasonography (US), and spectral domain optical coherence tomography (SD-OCT) to determine complete posterior vitreous detachment (PVD) confirmed by intraoperative findings of triamcinolone acetonide-assisted pars plana vitrectomy (PPV). METHODS: This prospective study included all consecutive patients admitted for surgical treatment of the epiretinal membrane (ERM) and macular hole (MH). The presence of complete PVD was determined one day before PPV using BM, US, SD-OCT. The preoperative findings were compared to the PVD status determined during PPV. RESULTS: A total of 123 eyes from 123 patients were included in the study. Indications for PPV included ERM in 57 (46.3%), full thickness macular hole in 57 (46.3%) and lamellar macular hole in 9 (7.3%) patients. Complete PVD during PPV was observed in 18 (31.6%; 95%CI:18.7-49.9) patients with ERM and 13 (19.7%; 95%CI:10.4-33.7) patients with MH. The sensitivity of preoperative BM, US, SD-OCT was 48.4% (95%CI:30.2-66.9), 61.3% (95%CI:42.2-78.2) and 54.8% (95%CI:36.0-72.7) respectively. The specificity of preoperative BM, US, SD-OCT was 81.5% (95%CI:72.1-88.9), 90.2% (95%CI:82.2-95.4) and 85.9% (95%CI:77.0-92.3) respectively. With a prevalence of 25.2% of PVD in our sample the positive predictive value of preoperative BM, US, SD-OCT was 46.9% (95%CI:29.1-65.3), 67.9% (95%CI:47.6-84.1) and 56.7% (95%CI:37.4-74.5) respectively. CONCLUSION: Preoperative BM, US, and SD-OCT showed relatively low sensitivity but also good specificity in assessing complete PVD. A combination of all three diagnostic methods can provide a good assessment of the vitreoretinal interface state.

Perifoveal Microvascular Changes following Internal Limiting Membrane Peeling Surgery for Epiretinal Membrane and Macular Hole.

INTRODUCTION: The aim of the study was to evaluate perifoveal microvasculature changes following pars plana vitrectomy with internal limiting membrane peeling for the epiretinal membrane (ERM) and macular hole (MH). METHODS: This retrospective study included 59 eyes from 59 patients. Subjects were divided into two groups: an ERM group (n = 43) and an MH group (n = 16) based on the initial diagnosis. Swept-source optical coherence tomography angiography (SS-OCTA) was performed in the macular area, pre- and postoperatively. Perifoveal microvascular changes were calculated using MATLAB from the 6 × 6 mm SS-OCTA images, excluding the foveal avascular zone. Pre- and postoperative perifoveal vessel densities (pfVDs) were separately analyzed in six sectors (superior, superotemporal, inferotemporal, inferior, inferonasal, and superonasal) in the superficial capillary plexus (SCP) and deep capillary plexus (DCP). The baseline characteristics and other clinical factors were compared between the ERM and MH groups. RESULTS: The postoperative best-corrected visual acuity significantly improved in both groups (p < 0.05). One year after surgery, the pfVD in the SCP of the ERM group significantly decreased in the inferotemporal sector (p = 0.049). The postoperative pfVD in the DCP of the MH group significantly decreased in temporal sectors (p < 0.05). The postoperative mean pfVD in the SCP in the MH group was significantly lower than that in the ERM group (p = 0.003). The presence of a dissociated optic nerve fiber layer (DONFL) was 75% in the MH group and 22% in the ERM group (p = 0.018). The correlation between the pfVD and DONFL was not statistically significant. CONCLUSION: Postoperative pfVD reduction in the temporal sector, a corresponding area in which DONFL is present after MH surgery, was significantly observed. After vitreoretinal surgery in MH patients, OCTA may serve as a useful tool for monitoring perifoveal microvascular changes, especially in temporal sectors.

TOPOGRAPHIC ASSESSMENT OF INTRARETINAL CYSTOID SPACE AND ITS PROGNOSTIC VALUES IN IDIOPATHIC EPIRETINAL MEMBRANE.

PURPOSE: To assess the topographical distribution of intraretinal cystoid space (IRC) and its prognostic value in idiopathic epiretinal membrane (iERM). METHODS: One hundred twenty-two eyes of iERM that had been followed up for 6 months after membrane removal were included. Based on the baseline IRC distribution, the eyes were divided into Groups A, B, and C (absence, IRC within 3 mm, and 6 mm from the fovea, respectively). The best-corrected visual acuity (BCVA), central subfield macular thickness (CSMT), ectopic inner foveal layer, and microvascular leakage (ML) were assessed. RESULTS: Fifty-six eyes (45.9%) had IRC, of which 35 (28.7%) were in Group B and 21 (17.2%) in Group C at baseline. Compared with group B, group C showed worse BCVA, thicker CSMT, and a greater association with ML (OR = 5.415; P = 0.005) at baseline; and also presented with worse BCVA, thicker CSMT, and wider distribution of IRC postoperatively. A wide distribution of IRC was an unfavorable baseline factor in achieving good visual acuity (OR = 2.989; P = 0.031). CONCLUSION: Widely distributed IRCs were associated with advanced disease phenotype as poor BCVA, thick macula, and baseline ML in iERM and also showed a poor visual outcome after membrane removal.

Assessment of histological and immunohistochemical features of retinal tissues using a novel tissue submission procedure.

We introduce a novel tissue submission procedure without additional equipment or storage facilities for assessing the histological and immunohistochemical features of retinal tissues. In total, 150 specimens were collected from patients who underwent vitrectomy or macular surgery from January to December 2020. Ninety-eight specimens were submitted using the new procedure, and 58 specimens were submitted as flat-mount slides to compare specimen adequacy. The tissues submitted using the new procedure were subjected to paraffin-embedding and sectioning for hematoxylin & eosin staining. Additional immunohistochemical analysis was performed to assess the cellular composition in retinal tissues with diverse etiologies. The new submission procedure had an adequacy ratio of 75.51%, which was comparable to that of the flat-mount method (p = 0.1397). The new method could produce high-quality images of histological features of tissues and facilitated immunohistochemical analysis to demonstrate cell origins. More glial cells (p = 0.000) and myofibroblasts (p = 0.012) were detected in the epiretinal membranes (ERMs) than in the internal limiting membranes (ILMs). Subgroup analysis revealed that secondary ERMs contained more macrophage-like cells (p = 0.001) and retinal pigment epithelial cells (p = 0.000) than did idiopathic ERMs. Our novel tissue submission procedure can be applied to routine clinical practice. Our study provides additional histological and immunohistochemical evidence of cellular components in retinal tissues based on a large number of human tissue samples. Moreover, tissues submitted using the new method can be permanently preserved, enabling future investigation for potential prognostic or therapeutic targets.

Long-term assessment of internal limiting membrane peeling for full-thickness macular hole using en face adaptive optics and conventional optical coherence tomography.

OBJECTIVE: To evaluate the long-term structural and microvascular retinal effects of internal limiting membrane peeling for full-thickness macular hole (FTMH) using en face adaptive optics optical coherence tomography (AO-OCT), conventional OCT, and OCT angiography (OCTA). DESIGN: Interventional case series. PARTICIPANTS: Patients with FTMH treated with vitrectomy, internal limiting membrane peeling, and gas tamponade. METHODS: Eleven eyes with FTMH that had at least 12 months of postoperative follow-up were enrolled in the study. En face AO-OCT was used to image the superficial retina in the peeled and nonpeeled areas. En face structural OCT was performed to image the inner retinal dimples (IRDs), macular thickness, and retinal nerve fibre layer (RNFL). En face OCTA was used to examine the integrity of the peripapillary nerve fibre layer (NFL) plexus. RESULTS: AO-OCT showed RFNL wrapping around the IRDs, and no obvious peripapillary NFL plexus dropout was seen with OCTA. Scattered hyper-reflective dots were observed on the surface of the peeled retina in all patients imaged with AO-OCT. No significant differences were found in IRD number (91.5 ± 24.4 versus 77.2 ± 14.7; P = 2.07), IRD proportionate area (8.36 ± 3.34 versus 7.53 ± 2.60; P = 0.159), or macular thickness between the 6- and 12-month (or greater) postoperative visits. CONCLUSION: IRDs do not to progress beyond 6 months postoperatively, and no obvious damage to RFNL and peripapillary NFL plexus was detected. Hyper-reflective dots on the surface of the retina suggestive of possible Müller cell reactive gliosis were identified with AO-OCT.

Assessment of Risk Factors Affecting Refractive Outcomes after Phacovitrectomy for Epiretinal Membrane.

PURPOSE: To investigate factors associated with refractive outcomes after phacovitrectomy for epiretinal membrane (ERM). METHODS: Retrospective review of patients undergoing phacovitrectomy for ERM was done. The main outcome measure was predictive refraction error (PE), defined as observed refraction error - target refraction error, calculated by the SRK/T, Haigis, and SRK II formulae. PE was measured at postoperative 1, 3, and 6 months. Simple and multiple linear regression analysis were used to evaluate factors associated with PE. RESULTS: A total of 53 eyes of 53 patients were included. The mean PEs at postoperative 1, 3, and 6 months were all negative, implying myopic shift in all patients regardless of the intraocular lens formula used. Haigis formula showed the least myopic shift among the three formulae (p = 0.001, Friedman test). There was no significant difference in PE depending on preoperative central macular thickness (CMT) in subgroup analysis. On stepwise multiple linear regression analysis, ERM etiology (ß = 0.759, p = 0.004, SRK/T formula; ß = 0.733, p = 0.008, Haigis formula; ß = 0.933, p < 0.001, SRK II formula), preoperative anterior chamber depth (ß = -0.662, p = 0.013, Haigis formula; ß = -0.747, p = 0.003, SRK II formula), and decrease of CMT (ß = -0.003, p = 0.025, SRK/T formula) were significantly associated with PE at postoperative 6 months. CONCLUSIONS: Myopic shift in PE was observed after combined phacovitrectomy for epiretinal membrane. ERM etiology, preoperative anterior chamber depth, and decrease of CMT were significantly associated with PE at postoperative 6 months. There was no difference in PE after surgery between the two groups defined by CMT (≥500 and <500 µm).

Long-Term Continuous Assessment of Internal Limiting Membrane Filling Induced Super-Large Macular Hole Healing.

PURPOSE: To assess the long-term continuous anatomical and functional healing process of a super-large full-thickness macular hole (FTMH) after internal limiting membrane (ILM) filling and air tamponade. DESIGN: Prospective, interventional case series. METHODS: Pars plana vitrectomy with ILM filling and air tamponade was performed in eyes with idiopathic super-large FTMH (> 900 µm). Patients were divided into 3 groups according to the macular hole (MH) diameter: group A, < 1000 µm; group B, 1000 to 1100 µm; and group C, > 1100 µm. The MH closure pattern was analyzed using optical coherence tomography. The preoperative and postoperative macular hole sensitivity, parafoveal sensitivity, and fixation status were assessed using a Microperimeter-3. The preoperative and postoperative best corrected visual acuity were measured. A monthly follow-up was conducted for 15 months postoperatively. RESULTS: Ninety-seven eyes from 96 consecutive patients with super-large FTMH were included in the study. Primary closure was seen in 93 of 97 eyes (95.88%), in which 88 of 97 eyes (90.72%) had a closed MH 1 week after surgery. The MH closure pattern continuously improved and significantly differed in the 3 groups (P < .05). Significant improvements in best corrected visual acuity (P < .01), parafoveal sensitivity (P < .05), and fixation stability (P < .01) were observed in all groups. CONCLUSIONS: Super-large FTMH (> 900 µm) closed promptly within 1 week postoperatively after ILM filling and air tamponade. The morphological and functional improvement lasted over an extended period postoperatively. No central scotoma enlargement was found regardless of the closure patterns, and there was significant retinal sensitivity and fixation status improvement.

Assessment of epiretinal membrane formation using en face optical coherence tomography after rhegmatogenous retinal detachment repair.

PURPOSE: To investigate epiretinal membrane (ERM) formation using en face optical coherence tomography (OCT) after vitrectomy for rhegmatogenous retinal detachment (RRD). METHODS: We retrospectively reviewed the medical records of 64 consecutive eyes (64 patients) with RRD treated by vitrectomy without ERM and internal limiting membrane peeling. ERMs and retinal folds were detected by B-scan and en face imaging. The maximum depth of retinal folds (MDRF) was quantified using en face imaging. ERM severity was staged using B-scan imaging. Main outcome measures were ERM detection rate with B-scan and en face imaging, MDRF, ERM staging, postoperative best-corrected visual acuity (BCVA; logarithm of the minimum angle of resolution), and risk factors for ERM formation. RESULTS: The detection rate for ERM formation was significantly higher with en face imaging (70.3%) than with B-scan imaging (46.9%; P = 0.007). There was no significant difference in postoperative BCVA between eyes with ERM formation (0.06 ± 0.26) and those without ERM formation (0.01 ± 0.14; P = 0.298). Forty of 45 (88.9%) eyes with ERM formation were classified as stage 1. Twenty-seven of 45 (60.0%) eyes with ERM formation developed parafoveal retinal folds. The mean MDRF was 27.4 ± 32.2 µm. Multiple retinal breaks and a maximum retinal break size of ≥ 2 disc diameters were significantly associated with ERM formation (P = 0.033 and P = 0.031, respectively). CONCLUSION: Although ERM formation was observed in 70.3% patients after RRD repair, the formed ERM was not severe and had minimal impact on the postoperative visual acuity.

Assessment of macular microvasculature features before and after vitrectomy in the idiopathic macular epiretinal membrane using a grading system: An optical coherence tomography angiography study.

PURPOSE: To evaluate pre- and postoperative microvasculature features in eyes with different idiopathic macular epiretinal membrane (iERM) classifications using optical coherence tomography angiography (OCTA). METHODS: In this retrospective study, 100 eyes with iERM were enrolled; 62 eyes underwent pars plana vitrectomy (PPV). All iERM eyes were evaluated and graded using optical coherence tomography (OCT). According to the thickness of the fovea relative to the surrounding macula from OCT radial line scans, we classified iERM into three grades. Optical coherence tomography angiography (OCTA) was used to measure the foveal avascular zone (FAZ)-related parameters and the superficial and deep capillary plexus layers using 3 × 3 mm scans. Measurements were taken at baseline and 3 months postoperatively. Best corrected visual acuity (BCVA), vessel density (VD), FAZ area, FAZ perimeter (PERIM), acircularity index (AI), and foveal vessel density (FD) were evaluated. RESULTS: Idiopathic macular epiretinal membrane (iERM) eyes with a higher grade had a lower FAZ area and perimeter (p < 0.0001), higher foveal vessel density (FVD) both in the superficial capillary plexus (SCP) (p < 0.0001) and in the deep capillary plexus (DCP) (p < 0.05), and a lower parafoveal vessel density (PRVD) in the DCP (p < 0.0001). The macular vessel density ratio (MVR = FVD/PRVD) increased with an increase in grade both in the SCP and in the DCP (p < 0.0001). For grade 1 iERM eyes, only PRVD in the DCP significantly changed before versus after the operation (p < 0.05). For grade 2 iERM eyes, the FAZ area and perimeter became larger after the operation (p < 0.05). The MVR of grade 2 iERM eyes decreased postoperatively both in the SCP (p < 0.05) and in the DCP (p < 0.001). For grade 1 and grade 2 iERM eyes, preoperative LogMAR BCVA was negatively correlated with the FAZ area (p < 0.01) and perimeter (p < 0.01), and was positively correlated with the MVR in the SCP (p < 0.05). Postoperative LogMAR BCVA was positively correlated with the FVD in the DCP (p < 0.05). CONCLUSIONS: Idiopathic macular epiretinal membrane (iERM) eyes of different grades have significant differences in microvasculature features. According to OCTA, eyes with higher grades have more serious microvascular changes. Grading plays a part in predicting postoperative microvascular characteristics, and grade 1 iERM eyes have a better visual outcome compared with grade 2 iERM eyes.

Combined phaco-vitrectomy provides lower costs and greater area under the curve vision gains than sequential vitrectomy and phacoemulsification.

PURPOSE: A majority of phakic patients undergoing pars plana vitrectomy for epiretinal membrane or macular hole require subsequent cataract surgery within 1-2 years. Combined phaco-vitrectomy eliminates the need for a second surgery and may enable patients to attain their best vision sooner. This study aims to compare the visual outcomes, complication rates, and costs of combined phaco-vitrectomy versus sequential vitrectomy followed by cataract surgery. METHODS: Records were searched by CPT® codes to identify patients with both cataract and vitrectomy surgery at our institution over a 5-year period (2013-2018). Chart review included medical history, demographics, exam findings, operating room records, visual acuity (VA), and clinical outcomes. Statistical analyses were performed with SPSS v19 (IBM). Area under the curve for visual acuity was calculated as the trapezoidal mean of the change in Early Treatment of Diabetic Retinopathy Study letters. RESULTS: After exclusion, 81 eyes of 78 patients underwent both cataract and vitrectomy surgeries at our institution. Thirty-four eyes underwent separate, sequential vitrectomy then phacoemulsification surgery, and 47 eyes had combined phaco-vitrectomy surgery. Total operating room times (120.81 ± 3.41 vs 161.03 ± 5.45 min; p < 0.0001) and associated costs were significantly lower in the combined surgery compared with those in the sequential surgery group. Baseline and final visual acuity were similar between the two groups. Baseline VA was 35.53 letters (~ 20/200) and 32.81 letters (~ 20/220) and increased to final VA of 63.74 (~ 20/53) and 60.91 letters (~ 20/61), in the sequential and combined groups respectively. Area under the curve for vision was greater in the combined surgery group, with subjects gaining an average of + 9.11 ± 3.32 letters from sequential surgery, and + 19.53 ± 3.53 letters in the combined surgery group (p = 0.04). Additionally, patients in the combined group attained their best visual acuity 449 days (15 months) sooner than those receiving sequential surgery. CONCLUSIONS: Combined phaco-vitrectomy surgery resulted in greater area under the curve visual acuity benefit and attainment of best visual acuity 15 months sooner compared with conventional sequential surgeries. There were no significant differences in complication rates or clinical outcomes between the groups, but operative times and costs were lower for combined surgery, supporting a favorable cost-benefit ratio. Graphical abstract.

Intraoperative optical coherence tomography in the full-thickness macular hole surgery with internal limiting membrane inverted flap placement.

PURPOSE: To describe the helpfulness of using intraoperative optical coherence tomography (OCT) during surgery for full-thickness macular hole (FTMH). OBSERVATIONS: This observational case series identifies three patients with FTMH who were treated with vitrectomy, internal limiting membrane (ILM) peel with inverted ILM flap, which was tucked into the MH, and air with 18% Sulfur Hexafluoride (SF6) gas tamponade. Intraoperative OCT was used to confirm positioning of the ILM flap, even after complete air-fluid exchange. The patients were followed for three months after surgery and all reached a good morphological and functional outcome. CONCLUSIONS: If confirmed by a prospective longitudinal study, the intraoperative OCT might become an important tool in assisting FTMH surgery.

INTERNAL LIMITING MEMBRANE PEELING DURING PARS PLANA VITRECTOMY FOR RHEGMATOGENOUS RETINAL DETACHMENT: Cost Analysis, Review of the Literature, and Meta-analysis.

PURPOSE: To evaluate the visual and potential economic impact of primary internal limiting membrane (ILM) peeling in primary treatment of rhegmatogenous retinal detachment. METHODS: A PubMed search was performed to extract data regarding the rate of epiretinal membrane formation and the rate of secondary pars plana vitrectomy with membrane peel after repair of rhegmatogenous retinal detachment with or without ILM peeling. Data were aggregated and analyzed in a meta-analysis. This information was used to perform a cost analysis to determine the economic ramifications of primary ILM peeling. RESULTS: Six included studies compared the outcomes of eyes receiving pars plana vitrectomy for rhegmatogenous retinal detachment repair with and without primary ILM peel. The cumulative rate of epiretinal membrane formation was 29% (86/295) in the eyes without ILM peel and 3% (8/289) in the eyes with ILM peel. The cumulative rate of secondary pars plana vitrectomy/membrane peel was 16% (22/141) in the eyes without ILM peel and 0% (0/158) in the eyes with ILM peel. The weighted summary point estimate odds ratio was 0.083 (95% confidence interval 0.042-0.164), indicating a statistically significant protective effect across the 6 studies of ILM peeling and the development of epiretinal membrane. Based on published data, the average dollars saved by conducting a primary ILM peel was $615 in a facility setting and $364 in an ambulatory surgical center. CONCLUSION: Published, mainly retrospective, data suggest that primary ILM peel in rhegmatogenous retinal detachment repair may have a significant reduction in the rate of postoperative epiretinal membrane and may lessen the need for secondary pars plana vitrectomy/membrane peel. Furthermore, from an economic perspective, the reduction in the need for secondary surgery may justify the higher cost with primary ILM peel.

The quantitative assessment of alterations in lens transparency after transconjunctival 27-gauge microincision vitrectomy surgery.

PurposeTo evaluate the baseline and post-vitrectomy lens densitometry values by a Scheimpflug camera in eyes with epiretinal membrane that were treated with 27-G microincision vitrectomy surgery (MIVS) without tamponade and to compare the results with those in fellow healthy eyes.Patients and methodsProspective case series. The lens densitometry measurements of 24 patients, who underwent 27-G MIVS without any tamponade for the treatment of epiretinal membrane, were taken preoperatively and on the first week, first month, and third month postoperatively with Pentacam HR-Scheimpflug imaging system.ResultsThe mean lens densitometry values at Zone 1 and average lens densitometry values significantly increased in the study eyes on the first month when compared with the preoperative values (P=0.011, P=0.033, respectively). Additionally, there were statistically significant differences regarding the mean lens densitometry values of Zone 1 and Zone 2, and also average lens densitometry values between the preoperative and third month postoperative values (P=0.003, P=0.021, P=0.009, respectively). However, the densitometry values of fellow eyes were similar at preoperatively and all the postoperative follow-up periods (P>0.05 for all).ConclusionsThis study suggests that 27-G MIVS might cause post-surgical lens density changes even in early postoperative months and vitreous may play an important role in protecting the transparency of the lens.

The Role of Inverted Internal Limiting Membrane Flap in Macular Hole Closure.

Purpose: To investigate the mechanism of macular hole (MH) closure following the inverted internal limiting membrane (ILM) technique. Methods: We performed the inverted ILM flap surgical technique as an experimental MH model in monkeys, and investigated the process of MH closure immunohistochemically. We then investigated the effects of type IV collagen, fibronectin, and laminin, which are constituent proteins of the ILM, on the proliferation and migration of cultivated Müller cells (MIO-M1). We also investigated the expression of neurotrophic factors and basic fibroblast growth factor (bFGF) in human ILM and MIO-M1 cells, and the effect of MIO-M1 migration on the expression of these factors, via immunohistochemical staining and the real-time reverse transcription polymerase chain reaction. Results: Ten days after inverted ILM flap surgery, the MH had closed and proliferating glial fibrillary acidic protein (GFAP)-positive cells surrounded the ILM. Type IV collagen, fibronectin, and laminin all enhanced the proliferation of MIO-M1 cells, and type IV collagen and fibronectin enhanced the migration of MIO-M1 cells. Neurotrophic factors and bFGF were present on the surface of the human ILM, and MIO-M1 cells produced these factors. Neurotrophic factors and bFGF were expressed to a significantly greater extent by migrating MIO-M1 cells than by these cells in their static state. Conclusions: During MH closure, the ILM functioned as a scaffold for the proliferation and migration of Müller cells, and may promote Müller cell activation. Neurotrophic factors and bFGF produced by activated Müller cells and present on the surface of the ILM may contribute to MH closure.

miRNAs in the vitreous humor of patients affected by idiopathic epiretinal membrane and macular hole.

PURPOSE: The aim of the present study was to assess the expression of miRNAs in the Vitreous Humor (VH) of patients with Macular Hole (MH) and Epiretinal Membrane (ERM) compared to a control group. METHODS: In this prospective, comparative study, 2-ml of VH was extracted from the core of the vitreous chamber in consecutive patients who underwent standard vitrectomy for ERM and MH. RNA was extracted and TaqMan® Low Density Arrays (TLDAs) were used to profile the transcriptome of 754 miRNAs. Results were validated by single TaqMan® assays. Finally, we created a biological network of differentially expressed miRNA targets and their nearest neighbors. RESULTS: Overall 10 eyes with MH, 16 eyes with idiopathic ERM and 6 controls were enrolled in the study. Profiling data identified 5 miRNAs differentially expressed in patients affected by MH and ERM with respect to controls. Four were downregulated (miR-19b, miR-24, miR-155, miR-451) and 1 was downregulated (miR-29a); TaqMan® assays of the VH of patients affected by MH and ERM, with respect to controls, showed that the most differentially expressed were miR-19b (FC -9.13, p:<0.00004), mir-24 (FC -7.52, p:<0.004) and miR-142-3p (FC -5.32, p:<0.011). Our network data showed that deregulation of differentially expressed miRNAs induces an alteration of several pathways associated with genes involved in both MH and ERM. CONCLUSION: The present study suggests that disregulation of miR-19b, miR-24 and miR-142-3p, might be related to the alterations that characterize patients affected by MH and ERM.

ASSESSMENT OF THE INTERNAL LIMITING MEMBRANE STATUS WHEN A MACULAR EPIRETINAL MEMBRANE IS REMOVED IN A PROSPECTIVE STUDY.

PURPOSE: To describe the presence and integrity of the internal limiting membrane (ILM) after removal of the macular epiretinal membrane (ERM) and to investigate the accuracy of tissue identification using surgical dyes when compared to histopathology results. METHODS: Patients with idiopathic ERM were enrolled in a prospective study and randomized to one of two surgical techniques. In one (Group M), only the ERM was deliberately removed and in the other (Group L) the ILM was also removed. Pars plana vitrectomy and extraction of the ERM with trypan blue dye were performed in all patients. The ILM status was assessed with brilliant blue G dye, and in Group L patients, the ILM was then removed. Histopathology was performed on all samples. RESULTS: Twenty-six patients underwent the study procedure: 11 in the Group M and 15 in the Group L. The patients' median age was 70.65 years (53-81), and the average follow-up was 15.35 months (4.86-25.10). The ILM extraction patterns were as follows: In Group M in block in 8 of 11 patients and partial in 3 of 11 patients; In Group L in block in 9 of 15 patients, partial in 5 of 15 patients and sequential in 1 of 15 patients. In only 3.8% of patients was the ILM intact after ERM removal. Thirty-two surgical samples were analyzed, containing both ERM and ILM, ERM only, or ILM only. In 84.37% of samples, the tissue identification using surgical dyes was consistent with identification according to pathological examination. This consistency was higher still at 96.7% when focused on ILM identification. CONCLUSION: It is technically difficult to extract the ERM in isolation from the ILM. There is good consistency between the content of removed tissue as identified using surgical dyes and the histopathological results of the samples. This is higher in ILM than in ERM.

Morphological and Functional Retinal Assessment in Epiretinal Membrane Surgery.

PURPOSE: To analyze functional and morphological findings after surgery for idiopathic epiretinal macular membrane (IEMM). MATERIALS AND METHODS: Twenty eyes of 20 patients affected by IEMM underwent 23-Gauge surgery. Morphological and functional examinations were assessed at baseline and at 30, 90, and 180 days after surgery. SD-OCT evaluated foveal morphology and thickness, photoreceptor inner/outer segment junction, and external limiting membrane. Functional assessment evaluated visual acuity, retinal sensitivity, and fixation patterns. Statistical analysis was performed with the Student's t test and Pearson correlation test. RESULTS: Mean central retinal thickness (CRT), visual acuity (VA), and retinal sensitivity (RS) at baseline were respectively 494.90 ± 38.73 µm, 0.55 ± 0.08 LogMAR, and 11.13±1.02; after surgery, at day 180, we observed a significant decrease in mean CRT to 326.90±32.68 µm, an increase in mean VA to 0.33 ± 0.05 LogMAR (p < 0.05), and in mean RS to 13.25 ± 0.73 dB (p < 0.05). A stable fixation increased from 40% of patients at baseline to 75% of patients at day 180 (p < 0.05). DISCUSSION: IEMM surgery results in continuous improvement in visual function, not only at month one but also beyond month six, due to the progressive reduction of residual intraretinal edema and recomposition of retinal layers.

Gene Expression Analysis of the Irrigation Solution Samples Collected during Vitrectomy for Idiopathic Epiretinal Membrane.

PURPOSE: The analysis of gene expression in idiopathic epiretinal membranes (iERMs) may help elucidate ERM formation and its pathology. Here, we conducted a case-control study, in order to determine the expression levels of cytokines and other genes in eyes with macular hole (MH) or iERM. METHODS: Twenty eyes, obtained from seven male and 13 female patients, were included in the study. The average age of the study subjects was 69.1 ± 7.67 years, and 15 eyes had iERM, while five eyes had MH. Irrigation solution samples were collected during vitrectomy, centrifuged, and the levels of cytokine and other mRNAs in the sediment were assessed using real-time PCR. The expression level of 11 cytokine genes, four transcription factor genes, two cytoskeletal genes, and genes encoding two extracellular matrix proteins in eyes with MH or iERM were determined and compared. RESULTS: The expression levels of interleukin 6 (IL6), tumor growth factor B2 (TGFB2), vascular endothelial growth factor A (VEGFA), chemokine C-X-C motif ligand 1 (CXCL1), v-rel avian reticuloendotheliosis viral oncogene homolog A (RELA), glial fibrillary acidic protein (GFAP), and tenascin C (TNC) were significantly higher in eyes with iERM than in eyes with MH. The expression of these genes was not associated with the preoperative visual acuity of the investigated patients. CONCLUSIONS: The obtained results indicate that real-time PCR analysis of irrigation solution samples collected during vitrectomy can help assess the expression levels of several genes, and that iERM is associated with the expression of pro-inflammatory genes and the genes expressed during angiogenesis and wound healing process (IL6, TGFB2, VEGFA, CXCL1, RELA, GFAP, and TNC).

Assessment of macular function, structure and predictive value of pattern electroretinogram parameters for postoperative visual acuity in patients with idiopathic epimacular membrane.

PURPOSE: To evaluate macular function and structure before and after epimacular membrane surgery and to estimate the usefulness of pattern ERG test parameters in predicting the postoperative visual acuity. METHODS: We evaluated 32 eyes of 32 patients (mean age 70.8 ± 6.7 years) before and 12 months after successful 25G pars plana vitrectomy with epimacular membrane removal and internal limiting membrane peeling. Distance best-corrected visual acuity (DBCVA-logMAR), foveal thickness (optical coherence tomography-OCT) and macular function [pattern electroretinogram-PERG (ISCEV standard): amplitudes (A) of P50- and N95-waves, implicit time (IT) of P50-wave] were assessed. To estimate the differences between the mean values of considered characteristics, the t test or Wilcoxon matched pair test was used. Correlation between preoperative data of PERG and preoperative and final DBCVA were investigated using Pearson correlation analysis. A receiver operating characteristic curve was constructed to obtain a cutoff value allowing prediction of visual prognosis. We tried to obtain the P50 and N95 amplitudes cutoff value in prediction of good visual outcome (DBCVA of 0.3 or less). RESULTS: Twelve months after surgery, mean of DBCVA significantly increased in comparison with preoperative value (0.31 ± 0.12 vs. 0.6 ± 0.15; p < 0.001) and 23/32 eyes (72 %) achieved visual improvement of two and more Snellen lines. In OCT test, the significant reduction in foveal thickness mean (313.34 ± 47.01 vs. 509.03 ± 93.88 µm; p < 0.001) was obtained. In PERG test, the significant increase in the mean amplitudes of P50- (AP50) and N95 (AN95)-waves as well as significant decrease in the mean implicit time (IT) of P50-wave were achieved (AP50: 3.41 ± 1.48 vs. 2.38 ± 1.23 µV; p < 0.001; AN95: 5.46 ± 1.72 vs. 3.75 ± 1.48 µV; p < 0.001; IT P50: 55.00 ± 3.60 vs. 56.75 ± 5.78 ms; p < 0.001). Twelve months postoperatively, DBCVA was significantly correlated with preoperative IT P50 (r = 0.39; p = 0.027), AP50 (r = -0.68; p < 0.001) and AN95 (r = -0.73; p < 0.001). CONCLUSION: Removal of idiopathic epimacular membranes with internal limiting membrane peeling not only provided increase in visual acuity and reduction in foveal thickness but also caused improvement of innermost retinal layer function in macular region. Pattern ERG test might be a valuable tool in predicting the postoperative visual acuity.

ASSESSMENT OF THE SIGNIFICANCE OF CYSTIC CHANGES AFTER EPIRETINAL MEMBRANE SURGERY WITH INTERNAL LIMITING MEMBRANE REMOVAL.

PURPOSE: To assess the prevalence and significance of cystic changes after internal limiting membrane peeling during epiretinal membrane surgery. METHODS: A retrospective review was performed on 64 patients who underwent pars plana vitrectomy with membranectomy for idiopathic epiretinal membrane between January 2010 and January 2012 by a single physician. Pars plana vitrectomy alone (Group 1, n = 32) or in combination with phacoemulsification (Group 2, n = 32) was performed. Peeling of the epiretinal membrane was assisted by triamcinolone, and internal limiting membrane was peeled up to the vascular arcades with the aid of brilliant blue dye. RESULTS: In Group 1, best-corrected visual acuity in logMAR (Snellen) improved from 0.53 ± 0.29 (20/68) at baseline to 0.23 ± 0.22 (20/34) at 6-month follow-up (P < 0.001). Two cases (6.3%) developed new cystic changes within the inner nuclear layer; however, there was no significant difference in best-corrected visual acuity at 6 months (P = 0.475). In Group 2, best-corrected visual acuity improved from 0.41 ± 0.17 (20/51) at baseline to 0.18 ± 0.15 (20/30) at 6 months (P < 0.001). Eight cases (25%) developed new inner nuclear layer cystic changes; however, there was no significant difference in best-corrected visual acuity at 6 months (P = 0.894). CONCLUSION: Development of new inner nuclear layer cystic changes after epiretinal membrane surgery may be a frequent finding, but in contrast to cystoid macular edema, it does not seem to affect visual recovery and should be observed. The combination of pars plana vitrectomy with cataract extraction may increase the risk of inner nuclear layer cystic changes.