Role of Hsa_circ_0000880 in the Regulation of High Glucose-Induced Apoptosis of Retinal Microvascular Endothelial Cells

Purpose

Circular RNAs (circRNAs) have been verified to participate in multiple biological processes and disease progression. Yet, the role of circRNAs in the pathogenesis of diabetic retinopathy (DR) is still poorly understood and deserves further study. This study aimed to investigate the role of circRNAs in the regulation of high glucose (HG)-induced apoptosis of retinal microvascular endothelial cells (RMECs).

Methods

Epiretinal membranes from patients with DR and nondiabetic patients with idiopathic macular epiretinal membrane were collected for this study. The circRNA microarrays were performed using high-throughput sequencing. Hierarchical clustering, functional enrichment, and network regulation analyses were used to analyze the data generated by high-throughput sequencing. Next, RMECs were subjected to HG (25 mM) conditions to induce RMECs apoptosis in vitro. A series of experiments, such as Transwell, the Scratch wound, and tube formation, were conducted to explore the regulatory effect of circRNA on RMECs. Fluorescence in situ hybridization (FISH), immunofluorescence staining, and Western blot were used to study the mechanism underlying circRNA-mediated regulation.

Results

A total of 53 differentially expressed circRNAs were found in patients with DR. Among these, hsa_circ_0000880 was significantly upregulated in both the diabetic epiretinal membranes and in an in vitro DR model of HG-treated RMECs. Hsa_circ_0000880 knockout facilitated RMECs vitality and decreased the paracellular permeability of RMECs under hyperglycemia. More importantly, silencing of hsa_circ_0000880 significantly inhibited HG-induced ROS production and RMECs apoptosis. Hsa_circ_0000880 acted as an endogenous sponge for eukaryotic initiation factor 4A-III (EIF4A3). Knockout of hsa_circ_0000880 reversed HG-induced decrease in EIF4A3 protein level.

Conclusions

Our findings suggest that hsa_circ_0000880 is a novel circRNA can induce RMECs apoptosis in response to HG conditions by sponging EIF4A3, offering an innovative treatment approach against DR.

Translational Relevance

The circRNAs participate in the dysregulation of microvascular endothelial function induced by HG conditions, indicating a promising therapeutic target for DR.

RETINAL OPTICAL COHERENCE TOMOGRAPHY IMAGING BIOMARKERS: A Review of the Literature

PURPOSE

The aim of this literature review was to summarize novel optical coherence tomography (OCT) imaging biomarkers that have recently been described in the literature and are frequently encountered clinically.

METHODS

The literature was reviewed to identify novel OCT biomarkers reported to date. A descriptive summary of all terms and representative illustrations were provided to highlight the most relevant features.

RESULTS

Thirty-seven OCT terminologies were identified. The vitreomacular interface disorder group included the four stages of epiretinal membrane, macular pseudohole, tractional lamellar hole (LH), degenerative LH, cotton ball sign, and foveal crack sign. The age-related macular degeneration group included outer retinal tubulation, multilayered pigment epithelial detachment, prechoroidal cleft, onion sign, double-layer sign, complete outer retinal atrophy, complete retinal pigment epithelium and outer retinal atrophy, and reticular pseudodrusen. The uveitic disorder group consisted of bacillary layer detachment, syphilis placoid, rain-cloud sign, and pitchfork sign. The disorders relating to the toxicity group included flying saucer sign and mitogen-activated protein kinase (MEK) inhibitor-associated retinopathy. The disorders associated with the systemic condition group included choroidal nodules and needle sign. The pachychoroid spectrum group included pachychoroid and brush border pattern. The vascular disorder group included pearl necklace sign, diffuse retinal thickening, disorganization of retinal inner layers, inner nuclear layer microcysts, hyperreflective retinal spots, paracentral acute middle maculopathy, and acute macular neuroretinopathy. The miscellaneous group included omega sign (ω), macular telangiectasia (type 2), and omega sign (Ω).

CONCLUSIONS

Thirty-seven OCT terminologies were summarized, and detailed illustrations consolidating the features of each biomarker were included. A nuanced understanding of OCT biomarkers and their clinical significance is essential because of their predictive and prognostic value.

Japan-epiretinal membrane (J-ERM) registry: A prospective cohort study protocol investigating the surgical outcome of epiretinal membrane

BACKGROUND

Epiretinal membrane (ERM) causes visual impairment such as reduction in visual acuity and metamorphopsia due to retinal traction. With the improvement of optical coherence tomography (OCT) and microincision vitrectomy surgery (MIVS), the surgery of ERM has significantly advanced. However, there have been no large-scale studies on the following: (1) how to evaluate visual impairment in ERM, (2) the relationship between OCT findings and visual function, (3) when is the optimal timing of surgery, and (4) the relationship between the surgical instruments as well as techniques and prognosis. The purpose of this study was to obtain evidence regarding these ERM surgeries.

METHODS AND DESIGN

This is a prospective, multicenter cohort study of ERM surgery in Japan from March 1, 2023, to March 31, 2027 (UMIN000048472, R-3468-2). Patients who underwent ERM surgery during the study period and agreed to participate in this study will be included. The goal is to have a total of 5,000 eyes surgically treated for ERM. The following data will be collected: age, gender, medical history, subjective symptoms, visual function before and 6 and 12 months after surgery, clinical findings, OCT data, surgical technique, instruments used in surgery, and complications.

DISCUSSION

The results of this study will support the surgical decisions and procedures in ERM practices.

Contrast Adaptation in Pseudophakic Patients with Macular Disorders

PURPOSE

To learn whether contrast adaptation, induced by positive spherical defocus, is compromised by macular disorders such as age-related macular degeneration (AMD) or epiretinal membranes (ERM) and to gain further insight in the functionality of the pathological macula and the level of "functional reserve" often postulated for the indication of presbyopia correcting IOLs.

METHODS

In a pilot study, patients with macular disorders, AMD and ERM, (n = 10) and healthy volunteers (n = 10) were tested to quantify contrast adaption after +4 D defocus for 10 min, by performing an interocular contrast matching task. Subjects manually adjusted the perceived contrast of the test patch as seen by the test eye to match to the contrast of a target patch with a fixed Michelson contrast of 0.2 as seen by the contralateral untreated eye.

RESULTS

Patients with macular disorders subjectively matched the 0.2 target contrast with a contrast of 0.24 ± 0.06 (mean ± SD) before adaptation and with a contrast of 0.19 ± 0.04 after adaptation (p < 0.05). Accordingly, patients with macular disorders showed an induced contrast gain by adaptation of 0.05 (27%), which was not different from the control group, which showed an induced contrast gain by adaptation of 0.06 (35%).

CONCLUSION

Patients with mild and moderate macular disorders, such as AMD and ERM, show an induced contrast adaptation, i.e. a gain in contrast sensitivity, at 3.2 cpd, which is not different in level from the induced contrast adaptation in healthy subjects. Macular disorders do not prevent adaptation of the patient's visual system to low contrast or blurred retinal images. Therefore, the implantation of presbyopia correcting IOLs is not a strict exclusion criterion for these patients, but the progressive nature of the macular disorder must be taken into account.

GENETIC FACTORS AND CHARACTERISTICS ON SPECTRAL-DOMAIN OPTICAL COHERENCE TOMOGRAPHY ARE ASSOCIATED WITH CHOROIDAL THICKNESS IN ABCA4 -RELATED RETINOPATHY

PURPOSE

To investigate the possible correlation factors of choroidal thickness in ABCA4 -related retinopathy.

METHODS

A total of 66 patients were included in the cohort. It is a retrospective, cross-sectional laboratory investigation. The patients were tested using whole-exon sequencing and ophthalmic examinations, including slit-lamp examinations, best-corrected visual acuity, spectral-domain optical coherence tomography, fundus photograph, and fundus autofluorescence.

RESULTS

Besides demographic characteristics (age, onset age, duration), we selected genetic factors and ocular characteristics on spectral-domain optical coherence tomography as the candidates related to choroidal thickness. Mutation type (inframe mutation or premature termination codon), epiretinal membrane, retinal pigment epithelium- Bruch membrane integrity, and macular curvature changes were identified as related factors to choroidal thickness in ABCA4 -related retinopathy after the adjustment of Logistic LASSO regression.

CONCLUSION

Mutation type, epiretinal membrane, retinal pigment epithelium-Bruch membrane integrity, and macular curvature changes are related factors to choroidal thinning. These findings could provide us a further understanding for the pathological process and clinical features of ABCA4 mutation.

Predictive factors for postoperative visual function in eyes with epiretinal membrane

Our current study aimed to investigate the association of preoperative OCT parameters with visual function after vitrectomy surgery in eyes with epiretinal membrane (ERM). This study enrolled 33 eyes with ERM that underwent vitrectomy surgery. In addition to visual acuity (VA), metamorphopsia was measured pre- and postoperatively for each eye. Using the preoperative horizontal and vertical OCT images, SUKIMA (the gap area between the ERM and retinal surface) was measured respectively and the average of horizontal SUKIMA and vertical SUKIMA was used for the analysis. The associations of baseline parameters (age, axial length, preoperative central retinal thickness [CRT], inner nuclear layer [INL] thickness, ectopic inner foveal layer [EIFL] and SUKIMA) with postoperative VA, the change in VA, postoperative metamorphopsia and the improvement in metamorphopsia were investigated using multivariate regression analysis followed by the model selection. The result suggested that age and INL thickness were related to the postoperative VA, whereas age and preoperative CRT were significantly associated with the change in VA. In contrast, only SUKIMA was correlated with the postoperative metamorphopsia, whilst age, EIFL and SUKIMA were associated with the improvement in metamorphopsia. Measuring SUKIMA might be useful for predicting postoperative metamorphopsia and the improvement in metamorphopsia in ERM eyes.

PEELING AND INTERNAL LIMITING MEMBRANE REPOSITION (PAIR) FOR MYOPIC FOVEOSCHISIS

PURPOSE

To report the outcomes of the Peeling and Internal Limiting Membrane Reposition (PAIR) technique in myopic foveoschisis.

METHODS

A retrospective case series of eyes with myopic foveoschisis that underwent vitrectomy and PAIR. Visual acuity, fundus photographs, and optical coherence tomography measurements were obtained and analyzed. Data are presented as medians (ranges).

RESULTS

A total of seven eyes underwent PAIR and were followed up for 339 days (188-436 days). No intraoperative complications were noted. One eye exhibited postoperative macular hole formation, but the hole was healed through fluid-gas exchange. At the last follow-up, the visual acuity had improved from 20/66 (20/332-20/40) to 20/40 (20/100-20/25), and the central foveal thickness had decreased from 576 µ m to 269 µ m. A repositioned internal limiting membrane (ILM) was observed in six of the eyes, and inner retinal dimples were noted in only two eyes. However, retinal wrinkles under the repositioned or perifoveal ILM were noted in five eyes.

CONCLUSION

The PAIR technique relieved traction, restored the ILM, and achieved functional and morphological improvement in eyes with myopic foveoschisis. Limited occurrence of inner retinal dimples and retinal thinning was noted, but retinal wrinkles occurred, likely due to ILM contracture.

Outer Retinal Hyperreflective Dots: A Potential Imaging Biomarker in Rhegmatogenous Retinal Detachment

PURPOSE

To investigate hyperreflective dots (HRDs) on baseline OCT in rhegmatogenous retinal detachment (RRD).

DESIGN

Retrospective cohort study.

SUBJECTS

Consecutive primary fovea-off RRDs presenting between January 2012 and September 2022.

METHODS

Visual acuity (VA) was obtained at baseline, 3, 6, and 12 months. Baseline foveal OCT scans were graded for the presence of HRDs in the outer retina, morphologic stage of RRD in the parafovea, and foveal photoreceptor integrity (intact, patchy or complete loss of the bacillary layer). Epiretinal membrane (ERM) and cystoid macular edema (CME) were graded after surgery.

MAIN OUTCOME MEASURES

The primary outcome was the proportion of patients in each morphologic stage with HRDs present on OCT and their association with postoperative VA. Secondary outcomes included association with the height of foveal detachment, duration of central vision loss, RRD extent, and development of ERM/CME.

RESULTS

A total of 351 patients were included. The presence of HRDs by morphologic stage of RRD was 0% in stage 1, 4.5% (2/42) in stage 2, 13% (7/54) in stage 3a, 16% (20/126) in stage 3b, 48% (40/83) in stage 4, and 85% (35/41) in stage 5. Hyperreflective dots were associated with increasing stage of RRD (P < 0.001), reduced integrity of foveal photoreceptors (P < 0.001), and reduced postoperative VA at 3, 6, and 12 months (P < 0.001), after excluding visually significant cataracts and adjusting for covariates. There was also a significant association between HRDs and height of foveal detachment, duration of central vision loss, and RRD extent (P < 0.001). Hyperreflective dots were neither associated with postoperative ERM formation nor with its severity (P = 0.27). Nevertheless, they were associated with the occurrence of CME at 3 and 6 months after surgery (P = 0.01; P = 0.006).

CONCLUSIONS

Hyperreflective dots have been hypothesized to consist of intraretinal inflammatory cells. We found that HRDs were significantly associated with the morphologic stage, extent, duration, and height of the RRD before surgery and with reduced VA and CME after surgery. Our results suggest that HRDs are associated with photoreceptor degeneration, as longstanding and extensive RRDs are more likely to present with HRDs. The association of HRDs with CME provides insight into the possible importance of inflammatory processes in RRD before and after surgery.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

360-degree pedicled inverted internal limiting membrane flap technique without face-down posturing for large idiopathic macular holes: a retrospective case series

PURPOSE

This study aimed to determine closure rates of large idiopathic macular holes treated with pars plana vitrectomy and 360-degree pedicled inverted internal limiting membrane flap without face-down posturing and define visual improvement, types of macular hole closure, and external retina integrity as secondary outcomes.

METHODS

This retrospective case series analyzed all patients who were treated by vitrectomy, 360-degree pedicled inverted internal limiting membrane flap, and gas tamponade, without face-down posturing postoperatively. Age, sex, time of visual acuity reduction, other ocular pathologies, and lens status were collected. The best-corrected visual acuity and optical coherence tomography results were recorded during pre- and postoperative follow-up examinations (15 days and 2 months after surgery).

RESULTS

This study enrolled 20 eyes of 19 patients, and the mean age was 66 years. Optical coherence tomography performed 2 months after surgery revealed hole closure in 19 (95%) eyes. The median best-corrected visual acuity improved from +1.08 preoperatively to +0.66 LogMAR 2 months postoperatively (p<0.001), with a median of 20 letters of visual improvement (0.4 LogMAR) on the Early Treatment Diabetic Retinopathy Study chart. V (47.36%)- and U (52.63%)-types of closure were observed.

CONCLUSION

The 360-degree pedicled inverted internal limiting membrane flap technique, without face-down posturing, provided a high closure rate (95%), external layer recovery, and V- and U-type foveal closure contours, in addition to visual improvement in most cases of large macular holes (even macular holes >650 μm). This technique may be a viable alternative to patients in whom traditional postoperative face-down positioning for large macular hole treatment is not possible.

Vertical asymmetry analysis of the macular microvasculature in epiretinal membrane patients with open-angle glaucoma

To identify the usefulness of vertical asymmetry analysis of the retinal microvasculature in epiretinal membrane (ERM) patients accompanied by open-angle glaucoma (OAG). Subjects were divided into three groups: normal controls (group 1), patients with ERM (group 2), and patients with both ERM and OAG (group 3). Retinal nerve fiber layer (pRNFL) and ganglion cell-inner plexiform layer (GC-IPL) thicknesses, vessel density (VD), and the absolute vertical difference of pRNFL (vdRNFL), GC-IPL (vdGC-IPL), and VD (vdVD) were compared among groups. Logistic regression analysis was performed to determine the factors associated with OAG. Diagnostic accuracy based on the area under the curve (AUC) was conducted. The VD of the full area was 20.9 ± 1.2, 20.0 ± 1.9, and 18.8 ± 2.2 mm-1 (P < 0.001) for groups 1, 2, and 3, respectively. The vdVD differed significantly between group 2 and group 3 (P < 0.001), whereas vdRNFL (P = 0.531) and vdGC-IPL (P = 0.818) did not show a significant difference. Multivariate logistic analyses showed that average pRNFL thickness (OR 0.924, P = 0.001) and vdVD (OR 5.673, P < 0.001) were significant factors associated with OAG in ERM patients. The AUC of the vdVD was 0.81 (95% CI 0.72-0.89), and the combination of average pRNFL thickness and vdVD had the highest AUC (0.87; 95% CI 0.78-0.95; P < 0.001). ERM patients with OAG had a significantly thinner pRNFL thickness, lower macular VD, and higher vdVD than those without OAG. Average pRNFL thickness and vdVD were significant factors associated with OAG in patients with ERM. Additionally, the combination of average pRNFL thickness and vdVD showed good diagnostic performance for OAG in patients with ERM.

Intravitreal allogeneic mesenchymal stem cells: a non-randomized phase II clinical trial for acute non-arteritic optic neuropathy

BACKGROUND

An effective treatment for acute non-arteritic ischemic optic neuropathy (NA-AION) has not been known or proven yet. Previous studies have suggested a neuroprotective effect of allogeneic bone marrow-derived mesenchymal stem cells. This study aims to report the results of a clinical trial on patients with acute non-arteritic optic neuropathy (NA-AION) treated with an intravitreal injection of allogeneic bone marrow-derived mesenchymal stem cells (BM-MSCs) (MSV®).

METHODS

We conducted a prospective, non-randomized, clinical phase-II study (Eudra CT number 2016-003029-40; ClinicalTrials.gov Registry NCT03173638) that included 5 patients with acute unilateral NA-AION diagnosed within 2 weeks after symptom onset and who received an intravitreal injection of allogeneic BM-MSCs (0.05 ml; cell concentration: 1.5 × 106cells/mL). The patients underwent regular ophthalmological examinations and were followed for one year.

RESULTS

In this trial, allogeneic BM-MSCs appeared to be safe as no patients developed signs of acute nor chronic intraocular inflammation or a significant change in intraocular pressure, although an epiretinal membrane was developed in one patient. A retrolental aggregate formed shortly after the injection spontaneously disappeared within a few weeks in another phakic patient, leaving a subcapsular cataract. Visual improvement was noted in 4 patients, and amplitudes of P100 on the visually evoked potentials recordings increased in three patients. The retinal nerve fiber layer and macular ganglion cell layer thicknesses significantly decreased during the follow-up.

CONCLUSIONS

Besides the development of an epiretinal membrane in one patient, the intravitreal application of allogeneic BM-MSCs appeared to be intraocularly well tolerated. Consequently, not only NA-AION but also BM-MSCs deserve more clinical investigational resources and a larger randomized multicenter trial that would provide stronger evidence both about safety and the potential therapeutic efficacy of intravitreally injected allogeneic BM-MSCs in acute NA-AION.

TRIAL REGISTRATION

Safety Assessment of Intravitreal Mesenchymal Stem Cells for Acute Non-Arteritic Anterior Ischemic Optic Neuropathy (NEUROSTEM). NCT03173638. Registered June 02, 2017 https://clinicaltrials.gov/ct2/show/NCT03173638 .

Macrophage-Myofibroblast Transition Contributes to Myofibroblast Formation in Proliferative Vitreoretinal Disorders

Inflammation and fibrosis are key features of proliferative vitreoretinal disorders. We aimed to define the macrophage phenotype and investigate the role of macrophage-myofibroblast transition (MMT) in the contribution to myofibroblast populations present in epiretinal membranes. Vitreous samples from proliferative diabetic retinopathy (PDR), proliferative vitreoretinopathy (PVR) and nondiabetic control patients, epiretinal fibrovascular membranes from PDR patients and fibrocellular membranes from PVR patients, human retinal Müller glial cells and human retinal microvascular endothelial cells (HRMECs) were studied by ELISA, immunohistochemistry and flow cytometry analysis. Myofibroblasts expressing α-SMA, fibroblast activation protein-α (FAP-α) and fibroblast-specific protein-1 (FSP-1) were present in all membranes. The majority of CD68+ monocytes/macrophages co-expressed the M2 macrophage marker CD206. In epiretinal membranes, cells undergoing MMT were identified by co-expression of the macrophage marker CD68 and myofibroblast markers α-SMA and FSP-1. Further analysis revealed that CD206+ M2 macrophages co-expressed α-SMA, FSP-1, FAP-α and ß-catenin. Soluble (s) CD206 and sFAP-α levels were significantly higher in vitreous samples from PDR and PVR patients than in nondiabetic control patients. The proinflammatory cytokine TNF-α and the hypoxia mimetic agent cobalt chloride induced upregulation of sFAP-α in culture media of Müller cells but not of HRMECs. The NF-ĸß inhibitor BAY11-7085 significantly attenuated TNF-α-induced upregulation of sFAP-α in Müller cells. Our findings suggest that the process of MMT might contribute to myofibroblast formation in epiretinal membranes, and this transition involved macrophages with a predominant M2 phenotype. In addition, sFAP-α as a vitreous biomarker may be derived from M2 macrophages transitioned to myofibroblasts and from Müller cells.

The development and evolution of lamellar macular hole in highly myopic eyes

BACKGROUND/OBJECTIVES

To study the development, evolution, outcomes, and prognostic factors of lamellar macular hole (LMH) in highly myopic (HM) patients.

METHODS

Fifty eyes from 47 HM patients with LMHs were retrospectively enrolled. Relevant pre- and post-LMH optical coherence tomography findings and visual acuity were collected. Structural progression was defined as an increase in the height of retinoschisis, and the development of foveal detachment, full-thickness macular hole, or retinal detachment.

RESULTS

Four traction-related developmental processes were identified. Type 1 LMHs (8, 16%) developed from foveal avulsion caused by vitreomacular traction. Type 2 (32, 64%) and type 3 LMHs (5, 10%) formed from ruptured parafoveal and central foveal cysts, respectively. Progressive foveal thinning caused by epiretinal membranes (ERMs) without cystic changes led to type 4 LMHs (5, 10%). Retinoschisis developed before (9 eyes), after (10 eyes), or simultaneously with (6 eyes) the LMH formation. Structural progression was noted in 50%, 53%, 0%, 100% of patients with type 1-4 LMHs, respectively. Multivariable Cox proportional hazard model showed that greater residual foveal thickness (P = 0.001, adjusted odds ratio = 0.22, 95% confidence interval [CI], 0.08 ~ 0.56), and the absence of retinoschisis were protective against structural progression. Multivariable linear regression showed that poor baseline visual acuity (P < 0.001, β = 0.74, 95% CI 0.41 ~ 1.07) and type 4 LMH predicted worse visual outcomes.

CONCLUSIONS

Four traction-related LMH developmental processes were observed in HM eyes and exhibited different evolution and outcomes. LMHs with foveal thinning induced by ERMs had the worst outcomes.

Primary ILM peeling during retinal detachment repair: a systematic review and meta-analysis

Epiretinal membrane (ERM) formation is a known postoperative complication following retinal detachment (RD) repair surgery. Prophylactic peeling of the internal limiting membrane (ILM) during surgery has been shown to reduce the risk of developing postoperative ERM formation. Some baseline characteristics and degrees of surgical complexity may act as risk factors for ERM development. In this review we aimed to investigate the benefit of ILM peeling in patients without significant proliferative vitreoretinopathy (PVR) who underwent pars plana vitrectomy for RD repair. A literature search using PubMed and various keywords retrieved relevant papers from which data were extracted and analyzed. Finally, the results of 12 observational studies (3420 eyes) were summarized. ILM peeling significantly reduced the risk of postoperative ERM formation (RR = 0.12, 95% CI 0.05-0.28). The groups did not differ in final visual acuity (SMD 0.14 logMAR (95% CI - 0.03-0.31)). The risk of RD recurrence (RR = 0.51, 95% CI 0.28-0.94) and the need for secondary ERM surgery (RR = 0.05, 95% CI 0.02-0.17) were also higher in the non-ILM peeling groups. In summary, although prophylactic ILM peeling appears to reduce the rate of postoperative ERM, this benefit does not translate into consistent visual recovery across studies and potential complications must be considered.

The outcomes and usefulness of Intraoperative Optical Coherence Tomography in vitreoretinal surgery and its impact on surgical decision making

Objective. To evaluate the utility of intraoperative OCT and its influence on the surgeon’s decision during vitreoretinal surgery.

Methods. This was a pilot, prospective case series conducted at a tertiary care ophthalmology department in Lahore, Pakistan. Sixteen patients undergoing vitreoretinal surgeries were included using the Leica Enfocus microscope integrated intraoperative optical coherence tomography (IOCT). We also investigated the changes in surgical decision making based on the findings revealed by IOCT using a questionnaire.

Results. 16 patients with a mean age of 40.6 ± 19.0 (range: 11-66) years, were included in the study; one case of acute postoperative endophthalmitis could not be imaged. The surgeon had to modify surgical decisions in four (26.7%) cases. IOCT clearly delineated various tissue planes for efficient and safe surgical dissection in pathologies such as posterior vitreous detachment, vitreomacular traction and epiretinal membranes. Furthermore, it also helped identifying perfluorocarbon-retina interface.

Conclusions. The intraoperative OCT modality is a feasible and useful intraoperative imaging technique for various kinds of vitreoretinal disorders. The decision making of the surgeon was modified in a quarter of the cases after the use of this newer modality.

Stalagmite-like pre-retinal deposits in the optical coherence tomography of two vitrectomy patients with panuveitis

Two patients with panuveitis are presented in whom, after undergoing a vitrectomy, the optical coherence tomography (OCT) revealed some unusual pre-retinal hyper-reflective deposits with the shape of stalagmites, distributed in a multifocal and perivascular pattern. Case 1: 51-year-old male with panuveitis in the right eye. After diagnostic-therapeutic vitrectomy, OCT showed pre-retinal stalagmite-like deposits. There was no clear aetiology, and the deposits persisted over the time. Case 2: 76-year-old woman with panuveitis in the right eye. After a surgery for cataract-vitrectomy and epiretinal membrane peeling, OCT revealed pre-retinal stalagmite-like deposits. The analysis reported elevated Toxoplasma IgG titres. Clarithromycin and corticosteroid were prescribed, resulting in the disappearance of pre-retinal deposits. The stalagmite-like deposits are not a very common tomographic sign of a posterior uveitis process, but they seem to correlate with inflammatory activity. There does not seem to be a clear mechanism or a particular aetiology.

Swept-source OCT reduces the risk of axial length measurement errors in eyes with cataract and epiretinal membranes

Aims

To compare the biometric data from partial coherence interferometry (PCI) and swept-source OCT (SS-OCT) in patients with age-related cataract and epiretinal membrane (ERM): ERM, ERM with foveoschisis and macular pseudohole.

Methods

49 eyes of 49 subjects including 36 ERM, 9 ERM foveoschisis and 4 macular pseudohole were analysed to evaluate the axial length (AL) measurements and the presence of AL measurement errors, defined basing on the shape of the biometric output graphs and on the concordance of AL values between instruments. Eyes with ERM were divided in four stages according to OCT features (i.e. presence/absence of the foveal pit, presence of ectopic inner foveal layers, disrupted retinal layers).

Results

The devices provided similar mean AL measurements in all subgroups, with differences <0.1 mm in 41/49 cases (83.6%). AL measurement errors were observed in ERM stages 3 and 4, characterized by ectopic inner foveal layers, and were significantly more frequent with the PCI (8/17, 47%) as compared with the SS-OCT device (2/17, 12%), p = 0.02. The refractive prediction error in cases with AL measurement errors was significantly greater using the PCI compared to the SS-OCT device (p<0.05).

Conclusion

Both devices provide reliable biometric data in the majority of patients and can be used in the preoperative assessment of patients with age-related cataract and ERM. In eyes with ectopic inner foveal layers, attention should be paid as AL measurement and refractive prediction errors may occur, more frequently with the PCI device.

Effect of internal limiting membrane peeling on postoperative visual acuity in macula-off rhegmatogenous retinal detachment

Purpose

To investigate the effects of internal limiting membrane (ILM) peeling on visual acuity (VA) after rhegmatogenous retinal detachment (RRD) surgery.

Methods

This retrospective analysis examined the medical records of patients with RRD who underwent vitrectomy at 26 institutions. To detect prognostic factors of VA at 6 months postoperatively (post-VA), multivariate linear regression was performed with post-VA as the objective variable; ILM peeling, sex, age, preoperative VA (pre-VA), intraocular pressure, axial length, duration of RRD, and cataract surgery served as explanatory variables. Recurrence of RRD and epiretinal membrane formation within 6 months postoperatively were compared between groups of patients with and without ILM peeling, among patients with macula-on and macula-off RRD.

Results

The inclusion criteria were met by 523 eyes with a macula-on RRD and 364 eyes with a macula-off RRD. ILM peeling was performed in 85 eyes with a macula-on RRD and 57 eyes with a macula-off RRD. In eyes with a macula-on RRD, ILM peeling did not affect post-VA (p = 0.72). Vitrectomy without cataract surgery and poor pre-VA were significantly associated with poor post-VA (p = 0.01 and p < 0.001, respectively). In eyes with a macula-off RRD, ILM peeling, long duration of RRD, and poor pre-VA were significantly associated with poor post-VA (p = 0.037, p = 0.007, and p < 0.001, respectively). Recurrence of RRD and epiretinal membrane formation were similar between groups of patients with and without ILM peeling, among patients with macula-on and macula-off RRD. Retina sensitivity was not evaluated by microperimetry.

Conclusion

ILM peeling did not affect post-VA in eyes with a macula-on RRD, whereas post-VA was worse in eyes with ILM peeling than in eyes without peeling, among eyes with a macula-off RRD.

The Proteome of Preretinal Tissue in Proliferative Vitreoretinopathy

BACKGROUND AND OBJECTIVE

Proliferative vitreoretinopathy (PVR) is the leading cause of retinal detachment repair failure. However, the molecular pathogenesis remains incompletely understood. Determining the proteome of PVR will help to identify novel therapeutic targets.

MATERIALS AND METHODS

Preretinal tissue samples, delaminated during surgery from six PVR cases and one idiopathic epiretinal membrane (ERM) were analyzed by mass spectrometry. Tandem mass spectra were extracted using the UniProt database, generating a list of 896 proteins, which were subjected to pathway set and fold-change (ERM vs PVR) analyses.

RESULTS

Two pathways were enriched in PVR: extracellular matrix (ECM) organization and extracellular structure organization. A fold-change analysis comparing mean total spectral counts from PVR to an ERM control identified fibronectin, the ECM glycoprotein, as the protein most significantly elevated in PVR compared to ERM.

CONCLUSION

These data identify pathwayskey to PVR progression, including thoseinvolved in cell-mediated ECM assembly and thus tractional force generation at the cellular level. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:S5-S12.].

In vitro culture Muller cell model to study the role of inverted internal limiting membrane flap technique in macular hole closure

Inverted internal limiting membrane (ILM) flap may constitute a scaffold for Muller cells whose migration and proliferation on its surface begin the process of macular hole closure. The goal of the study was to establish an in vitro model of the interaction between ILM and the Muller cells. Vitrectomy with inverted ILM flap was performed in 23 patients due to a full-thickness macular hole (FTMH). After dissection of the inverted flap, the area of ILM peeling was extended and material was collected for cell culture experiments. Muller cells cultured on adherent cell plates showed significantly better growth than on suspension plates. Our results reveal that the presence of the ILM can overcome the growth inhibitory effect of the non-adhesive surface. Moreover, the ILM appears to be the optimal growth surface under normoxia conditions mimicking the microenvironment after vitrectomy and hypoxia which is natural state for Muller cells. The closure rate of FTMH was 100%. Our study revealed that in non-adhesive culture conditions patient derived ILM constitutes an optimal growth surface for Muller cells. We have demonstrated that the ILM effectively stimulates attachment, proliferation, and survival of Müller cells in conditions of normoxia which is the case after vitrectomy. The results strongly advocate for the use of inverted ILM flap method in macular hole closure surgeries.

[Surgery of large and persistent macular holes]

Modern macular hole surgery results in high closure rates of over 90% and good functional results especially in macular holes up to 400 µm in diameter. The standard of care in most of these cases consists of transconjunctival sutureless pars plana vitrectomy, peeling of the inner limiting membrane (ILM) around the hole, followed by gas tamponade and positioning of the patient. As closure rates and functional results decrease with larger macular hole diameters over approximately 400 µm, alternative surgical techniques have been introduced to improve anatomical and functional results in these cases. These techniques include the positioning of tissue within the macular hole to improve hole closure. This can be performed using an ILM flap or free flap technique and the transplantation of autologous retinal tissue, lens capsule or homologous amniotic tissue in or under the defect. An alternative promising approach is the attenuation of the rim of the hole by induction of a localized retinal detachment at the posterior pole which is achieved by subretinal injection of balanced salt solution (BSS) using a 41 gauge needle. The operation is completed by an endotamponade using gas or silicone oil.

Nanomechanical mapping helps explain differences in outcomes of eye microsurgery: A comparative study of macular pathologies

Many ocular diseases are associated with an alteration of the mechanical and the material properties of the eye. These mechanically-related diseases include macular hole and pucker, two ocular conditions due to the presence of abnormal physical tractions acting on the retina. A complete relief of these tractions can be obtained through a challenging microsurgical procedure, which requires the mechanical peeling of the internal limiting membrane of the retina (ILM). In this paper, we provide the first comparative study of the nanoscale morphological and mechanical properties of the ILM in macular hole and macular pucker. Our nanoscale elastic measurements unveil a different bio-mechanical response of the ILM in the two pathologies, which correlates well to significant differences occurring during microsurgery. The results here presented pave the way to the development of novel dedicated microsurgical protocols based on the material ILM properties in macular hole or pucker. Moreover, they contribute to clarify why, despite a common aetiology, a patient might develop one disease or the other, an issue which is still debated in literature.

[Morphology of the vitreoretinal interface in fellow eyes of patients with full thickness macular holes]

PURPOSE

We performed a retrospective, observational clinical study to evaluate the vitreoretinal interface (VRI) in fellow eyes of patients with full thickness macular holes (FTMH) based on spectral domain optical coherence tomography (SD-OCT) examinations.

METHODS

The VRI in fellow eyes of 38 patients with idiopathic FTMH, 6 of which had concomitant vitreomacular traction (VMT) and the VRI of 32 patients with FTMH with complete resolution of VMT were examined by SD-OCT for the presence of vitreomacular adhesion (VMA), VMT and the formation of FTMH, lamellar macular holes (LMH), macular pseudoholes (MPH) or epiretinal membranes (ERM). Patients underwent complete ophthalmic evaluation, including SD-OCT at baseline and follow-up visits. To classify the morphology of the VRI, we used the international vitreomacular traction study classification system by Duker et al. (Ophthalmology 2013), evaluating the baseline SD-OCT data for significant classification parameters, including size of VMA, macular thickness and volume and structural changes of retinal layers.

RESULTS

Of the 38 eyes with FTMH, 2 (5.3%) fellow eyes also showed evidence of FTMH, 5 (13.2%) had isolated VMT while 5 (13.2%) showed formation of ERM, of which 2 demonstrated MPH. In 5 patients (13.2%) showing evidence of VMA and 17 patients (44.7%) with an unremarkable VRI, 22 fellow eyes (57.9%) showed no pathological morphology. Altogether, 16 fellow eyes (42.1%) of patients with FTMH showed pathological changes of the vitreoretinal interface.

CONCLUSION

This high-resolution SD-OCT-based retrospective study showed that fellow eyes of patients with VMT or FTMH were at increased risk of demonstrating pathological changes in the morphology of the VRI.

[Two-port pars plana vitreomacular surgery without endoillumination]

PURPOSE

To present a two-port endovitreal surgery technique without endoillumination as a method of choice for sparing surgery of the macular area.

MATERIAL AND METHODS

Study group included 16 patients (16 eyes) with cataract and macular pathology (8 - with a macular hole (MH) and 8 - with epiretinal fibrosis). Preoperative mean best corrected visual acuity (BCVA) was 0.15±0.10. The maximum follow-up period lasted 6 months. All surgeries were performed by the same specialist using surgical microscope OMS-800™ ('Topcon') fitted with visualization system OFFISS (Optical Fiber-free Intravitreal Surgery System) and 3D visualization system NGENUITY (Alcon). In each case, cataract phacoemulsification with IOL implantation was performed prior to two-port 25-27G pars plana vitrectomy. One port was used for placing the irrigation cannula, the other - for injection of various tools. The light of the microscope tube was used for illumination. Light and color parameters were set up using Alcon NGENUITY 3D visualization system for the microscope light to be used at minimal required intensity that achieved adequate, clear image.

RESULTS

The two-port surgery was successfully performed in all 16 patients of the study group. Neither intraoperative nor postoperative complications were observed. There was no rise or decrease in intraocular pressure (IOP) within the specified follow-up period. In the postoperative period, anatomical results were evaluated by optical coherent tomography (OCT). The hole was blocked successfully in all cases, and the epiretinal membrane (ERM) could not be determined. Mean BCVA increased to 0.5±0.3.

CONCLUSION

The technique of two-port surgery without endoillumination allows safe and effective surgical treatment of the macular pathology.

Preoperative macular spectral-domain optical coherence tomography in patients considering advanced-technology intraocular lenses for cataract surgery

PURPOSE

To evaluate spectral-domain optical coherence tomography (SD-OCT) as a strategy for identifying occult macular disease preoperatively in patients scheduled for cataract surgery with implantation of an advanced-technology intraocular lens (IOL).

SETTING

Private practice, Danbury, Connecticut, USA.

DESIGN

Retrospective consecutive case series.

METHODS

Macular SD-OCT scans were performed on all patients scheduled for cataract surgery and Restor multifocal or toric IOL implantation over a 6-month period. All scans were reviewed for abnormalities of the retina, retinal pigment epithelium, or vitreomacular interface. For subgroup analysis, the following health information was collected: age, sex, smoking history, hypertension, heart disease, hyperlipidemia or hypercholesterolemia, and diabetes.

RESULTS

Two hundred sixty-five consecutive scans from 149 patients were obtained. Macular pathology was found in 35 eyes (13.2%). The most common condition was age-related macular degeneration in 15 eyes (5.66%) followed by idiopathic epiretinal membrane in 11 eyes (4.15%). Ischemic atrophy from previously undiagnosed retinal vascular pathology was found in 5 eyes (1.89%) and edema in 3 eyes (1.13%). A subgroup analysis found a higher incidence of macular pathology in patients with a history of heart disease (30.6%, P < .001) or smoking (20.2%, P < .05), and in men (23.9%, P < .01). Media opacities precluded interpretation of 17 scans (6.42%).

CONCLUSION

Preoperative macular SD-OCT scanning was effective in identifying patients at risk for compromised visual outcomes after advanced-technology IOL surgery.

FINANCIAL DISCLOSURE

None of the authors has a financial or proprietary interest in any material or method mentioned.

Direct cost of pars plana vitrectomy for the treatment of macular hole, epiretinal membrane and vitreomacular traction: a bottom-up approach

PURPOSE

The direct cost to the National Health Service (NHS) in England of pars plana vitrectomy (PPV) is unknown since a bottom-up costing exercise has not been undertaken. Healthcare resource group (HRG) costing relies on a top-down approach. We aimed to quantify the direct cost of intermediate complexity PPV.

METHODS

Five NHS vitreoretinal units prospectively recorded all consumables, equipment and staff salaries during PPV undertaken for vitreomacular traction, epiretinal membrane and macular hole. Out-of-surgery costs between admission and discharge were estimated using a representative accounting method.

RESULTS

The average patient time in theatre for 57 PPVs was 72 min. The average in-surgery cost for staff was £297, consumables £619, and equipment £82 (total £997). The average out-of-surgery costs were £260, including nursing and medical staff, other consumables, eye drops and hospitalisation. The total cost was therefore £1634, including 30 % overheads. This cost estimate was an under-estimate because it did not include out-of-theatre consumables or equipment. The average reimbursed HRG tariff was £1701.

CONCLUSIONS

The cost of undertaking PPV of intermediate complexity is likely to be higher than the reimbursed tariff, except for hospitals with high throughput, where amortisation costs benefit from economies of scale. Although this research was set in England, the methodology may provide a useful template for other countries.

Observation of persistent fundus fluorescence after internal limiting membrane peeling assisted by indocyanine green solution of different concentrations

PURPOSE

To investigate how long indocyanine green (ICG) remains in the fundus after vitreoretinal surgery assisted with ICG, and to identify factors that influence the persistence duration.

METHODS

Fifty five eyes diagnosed as idiopathic macular hole (Stage 2 and 3) were randomly divided into five groups. ICG solution at concentrations of 5, 2.5, 2.5, 1.25, and 0.5 mg/ml, employed in cases of Group I to V respectively, was applied to stain the internal limiting membrane (ILM) during the procedure of internal limiting membrane peeling. A prospective study was carried out after pars plana vitrectomy and ILM peeling were performed on 55 eyes with Stage 2, 3, or 4 idiopathic macular holes. Infrared fundus pictures were obtained in all patients before and after surgery.

RESULTS

High levels of fluorescence from residual ICG (ICG hyperfluorescence) were mainly localized at the posterior pole of the fundus after surgery. In Group Ⅰ, Ⅱ, III, IV and V, the duration of persistence of flurorescence from ICG was 8.33±0.87, 3.59±0.94, 3.75±0.79, 2.30±0.48, and 1.29±0.49 months, respectively. Although no significant difference was detected between Group Ⅱ and Group III, the general inter-group difference was significant among the five groups in which different ICG concentration was applied. In Group III, even though 90% of the macular holes acquired anatomical closure, ICG hyperfluorescence was detected in the macular area.

CONCLUSION

ICG remains in the fundus for a period of months. The persistence duration of fluorescence from ICG is positively correlated with the concentration and the staining time of ICG. Hyaluronan is beneficial in reducing the amount of ICG residue in the macular area.

Retinal arterial macroaneurysm with blood-staining of the internal limiting membrane and optic nerve

An 83-year-old man presented with a retinal arterial macroaneurysm complicated by vitreous hemorrhage, hyphema and ghost cell glaucoma requiring surgical intervention. After pars plana vitrectomy, anterior chamber wash-out and laser photocoagulation, the retinal arterial macroaneurysm closed but blood-staining of the optic nerve, internal limiting membrane and peripapillary vessels persisted. The rare sequela of blood-staining, which in this case did not adversely affect the final visual outcome, further contributes to our understanding of the wide ranging clinical spectrum of retinal arterial macroaneurysms.

[Nd:YAG Laser for retrohyaloidal haemorrhage after retinal branch vein occlusion]

BACKGROUND

A retrohyaloidal haemorrhage can be caused by different underlying diseases. Usually dense haemorrhages are treated by early vitrectomy. We want to report the successful treatment of a retrohyaloidal haemorrhage by means of Nd:YAG laser membranotomy.

MATERIALS AND METHODS

A 47-year-old man noticed two weeks before presentation a sudden visual loss in the left eye. Visual acuity on the first visit was c. c. 20/32 OD and c. c. 20/400 ex. OS. Dilated fundus examination of the left eye showed multiple intraretinal haemorrhages in the superior periphery and a dense retrohyaloidal haemorrhage over the macula. Anamnestic risk factors for ocular bleeding were systemic hypertension in connection with adiposity.

RESULTS

A retinal branch vein occlusion with retrohyaloidal haemorrhage due to systemic hypertension was diagnosed. To drain the retrohyaloidal haemorrhage into the vitreous an Nd:YAG laser membranotomy of the anterior surface of the haemorrhage was performed. Visual acuity increased to 20/100 within 30 min.

CONCLUSION

Possible therapeutic options to manage retrohyaloidal haemorrhages are observation, primary vitrectomy and Nd:YAG laser membranotomy. The presented case shows laser membranotomy to be a promising possibility for a rapid resolution of retrohyaloidal haemorrhage in selected patients.

[Detection of C5a receptor expressions on human epiretinal membranes and cultured RPE cells by immunohistochemical staining]

AIM

To observe the expression and distribution of C5a receptor(C5aR) on epiretinal membranes (ERM) tissue from patients with proliferative retreous body-retina (PVR) lesion and cultured retinal pigmentary epithelial (RPE) cells.

METHODS

The C5aR expressions on ERM tissue and cultured RPE cells were detected by ABC immunohistochemical staining with mouse anti-human C5aR mcAbs.

RESULTS

Expression of C5aR was found in ERM tissue and on cultured RPE cells as well as macrophages.

CONCLUSION

As a pro-inflammatory factor, binding of C5a to C5aR on RPE cells may play an important role in the development of PVR.