Identification of epiretinal proliferation in various retinal diseases and vitreoretinal interface disorders

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.

En Face OCT Detects Preretinal Abnormal Tissues Before and After Internal Limiting Membrane Peeling in Eyes with Macular Hole

PURPOSE

To assess preretinal abnormal tissue (PAT) using en face OCT in eyes with idiopathic macular holes (MHs).

DESIGN

Retrospective, observational study.

PARTICIPANTS

Patients with MH who received 6 × 6-mm spectral-domain-OCT scans.

METHODS

Preretinal abnormal tissue was detected by en face OCT images with a custom slab, defined with an anterior boundary of 6 μm anterior to the internal limiting membrane (ILM) and a posterior boundary at 3 μm posterior to the ILM. The PAT was defined as any abnormal tissues observed in en face OCT.

MAIN OUTCOME MEASURES

Characteristics of preoperative and postoperative PAT.

RESULTS

Sixty eyes with MH from 60 patients were included. Fifty-one eyes underwent preoperative analysis, and 46 eyes underwent postoperative examination. Before surgery, 48 (94%) eyes had a mean (standard deviation [SD]) PAT of 6.6 (9.8) mm². The corresponding cross-sectional OCT showed PAT consisting of epiretinal proliferation, epivascular glia, and a preretinal hyperreflective band. Preretinal abnormal tissue was contiguous to the hole (peri-MH PAT) in 12 eyes (24%), whereas others (36 eyes, 76%) had a scattered distribution (extrafoveal PAT). The area of PAT was greater in eyes with a peri-MH PAT than in eyes with an extrafoveal PAT (P < 0.0001). Compared to the eyes with the extrafoveal PAT, the eyes with the peri-MH PAT were associated with men (P = 0.0059) and worse baseline visual acuity (VA) (P = 0.0002). In eyes with ILM peeling (42 eyes), postoperative PAT proliferation was observed from the edge of the ILM peeling toward the periphery over a 1-year follow-up. The mean (SD) area of PAT at 2 weeks after surgery was 3.4 (3.6) mm² and increased to 12.1 (6.4) mm² at 12 months (P < 0.0001). However, no PAT increase was observed in 4 eyes that underwent vitrectomy without ILM peeling. The postoperative PAT size was not associated with the postoperative VA.

CONCLUSIONS

En face OCT revealed PAT in most eyes with MHs. Peri-MH PAT was associated with worse VA and was seen more frequently in male patients. Postoperative PAT proliferation may be triggered by ILM peeling, but it is not associated with worse VA.

Foveal microstructure and visual function in patients with lamellar macular hole, epiretinal membrane foveoschisis or macular pseudohole

PURPOSE

To compare the foveal microstructures, such as the prevalence of epiretinal proliferation (EP) and residual ellipsoid zone (EZ), in eyes with lamellar macular hole (LMH), epiretinal retinal membrane (ERM) foveoschisis and macular pseudohole (MPH), and to investigate the association of the foveal microstructure with visual functions.

METHOD

In addition to the prevalence of EP, we calculated the residual EZ index within 1mm and 3 mm (rEZ1 and rEZ3) in all examined eyes. Comparisons were conducted to baseline characteristics (logMAR visual acuity [logMAR VA], metamorphopsia score [Mave], central retinal thickness [CRT], the prevalence of EP, rEZ1 and rEZ3) between MPH, ERM foveoschisis and LMH subgroups. The relationships (1) between logMAR VA and each of age, type (MPH, ERM foveoschisis and LMH), the prevalence of EP, rEZ1, rEZ3, spherical equivalent (SE) and CRT and (2) between Mave and each of variables were investigated.

RESULTS

Fifty-one eyes of 48 patients were enroled. The mean age was 65.2 ± 11.1 years. Ten eyes were diagnosed as LMH, 22 eyes as ERM foveoschisis and 19 eyes as MPH, respectively. There was a significant difference in CRT only between LMH and ERM foveoschisis (p = 0.023). There was a tendency toward significance in rEZ1 between LMH and ERM foveoschisis (p = 0.057), but not in rEZ3. The optimal model for logMAR VA included age, rEZ1, SE and CRT. On the other hand, the optimal model for Mave included the prevalence of EP, rEZ1 and SE.

CONCLUSION

Microstructural observations are useful to predict visual functions in LMH, ERM foveoshisis and MPH.

Increased Macrophage-like Cell Density in Retinal Vein Occlusion as Characterized by en Face Optical Coherence Tomography

Objectives: to quantitatively analyze macrophage-like cells (MLCs) at the vitreoretinal interface in retinal vein occlusion (RVO) using swept-source optical coherence tomography angiography (SS-OCTA) and en face optical coherence tomography (OCT). Methods: The study included 72 RVO patients, with 43 acute patients and 29 chronic patients. For a normal control, 64 fellow eyes were included. MLCs were visualized in a 5 μm en face OCT slab above the vitreoretinal interface centered on the fovea. After semi-automatic binarization and quantification, we evaluated the MLC count and density among groups. We also investigated the MLC density and distribution relative to retinal edema. Results: Morphological changes and congregation of MLCs appeared in RVO eyes. The MLC density of both the acute and chronic groups was significantly higher than that of the control eyes (p < 0.001). In the acute group, the MLC density of the edematous region was lower than both the non-edematous region (p < 0.001) and the whole image (p < 0.01). The MLC density in acute eyes was negatively correlated to central fovea thickness (CFT) (r = −0.352, p < 0.05). The MLC density in chronic eyes was positively correlated to CFT and mean retina thickness (MRT) (r = 0.406, p < 0.05; r = 0.412, p < 0.05, respectively). Conclusions: SS-OCTA is a viable and simple method for the characterization of MLCs at the vitreoretinal interface. A significant increase in the MLC density in both acute and chronic eyes implicates the activation and recruitment of MLCs in RVO and that the MLC density and distribution can be affected by retinal edema.

Inner limiting membrane peeling prevents secondary epiretinal membrane after vitrectomy for proliferative diabetic retinopathy

AIM

To evaluate the role of internal limiting membrane (ILM) peeling in preventing secondary epiretinal membrane (ERM) formation in pars plana vitrectomy (PPV) for proliferative diabetic retinopathy (PDR).

METHODS

This retrospective study analyzed the medical records of patients who underwent PPV for PDR and were followed up for minimum 3mo. ILM peeling was performed based on the intraoperative surgeons' judgments. ERM was assessed by optical coherence tomography photography. The relationship between ILM peeling and postoperative ERM was analyzed.

RESULTS

In total, 212 eyes from 197 patients were included in this study. The incidence of secondary ERM in the ILM non-peeling group was significantly higher than that in the ILM peeling group (37.0% vs 14.0%; P<0.001). Multivariate logistical regression revealed that ILM peeling was highly associated with the prevention of secondary ERM development [odds ratio 0.38; 95% confidence interval 0.17-0.86; P<0.05].

CONCLUSION

ILM peeling during PPV for PDRs can effectively reduce the incidence of secondary ERM development and is worth consideration by vitreoretinal surgeons.

The clinical and pathogenic significance of atypical epiretinal tissue in macular hole

With the recent advent of high-resolution optical coherence tomography (OCT), atypical epiretinal tissue (AET), also known as epiretinal proliferation, has been frequently noted in various pathologies. AET presents as premacular tissue with homogenous medium reflectivity over the internal limiting membrane on OCT. Although AET is most frequently associated with a lamellar hole (LH), some cases of macular hole (MH) also accompany AET at the edge of the hole. MH with AET has been reported to have worse clinical and surgical outcomes than MH without AET. The imaging and histopathological findings of AET imply that the development of MH with AET may not have been driven by vitreofoveal traction. Instead, MH with AET might have evolved from LH with AET. This mini-review encompassed relevant studies on MH with AET published to date and explained the clinical, prognostic, and pathogenic significance of AET in MH in detail.

Primary Lamellar Macular Holes: To Vit or Not to Vit

There is a wide spectrum of macular conditions that are characterized by an irregular foveal contour caused by a break in the inner fovea. These include full-thickness macular hole (FTMH), foveal pseudocyst, lamellar macular hole (LMH) and macular pseudohole (MPH). Clinical examination of vitreomacular interface disorders is notoriously poor in differentiating these conditions. These conditions were initially described with slit-lamp biomicroscopy, and the main goal was to distinguish an FTMH from the others. The introduction of optical coherence tomography (OCT) has revolutionized our understanding of the foveal microstructural anatomy and has facilitated differentiating these conditions from an FTMH. However, the definitions of the other conditions, particularly LMH, has evolved over the past two decades. Initially the term LMH encompassed a wide spectrum of clinical conditions. As OCT became more widely used and observations became more refined, two different phenotypes of LMH became apparent, raising the question of different pathogenic mechanisms for each phenotype. Tractional and degenerative pathological mechanisms were proposed. Epiretinal membranes (ERMs) associated with each phenotype were identified. Typical ERMs were associated with a tractional mechanism, whereas an epiretinal proliferation was associated with a degenerative mechanism. Epiretinal proliferation represents Müller cell proliferation as a reactive process to retinal injury. These two types of ERM were differentiated by their characteristics on SD-OCT. The latest consensus definitions take into account this phenotypic differentiation and classifies these entities into LMH, MPH and ERM foveoschisis. The initial event in both ERM foveoschisis and LMH is a tractional event that disrupts the Müller cell cone in the foveola or the foveal walls. Depending on the extent of Müller cell disruption, either a LMH or an ERM foveoschisis may develop. Although surgical intervention for LMH remains controversial and no clear guidelines exist for pars plana vitrectomy (PPV), eyes with symptomatic, progressive ERM foveoschisis and LMH may benefit from surgical intervention.

Epiretinal proliferation after rhegmatogenous retinal detachment

PURPOSE

To determine the characteristics and appearance rate of epiretinal proliferation (ERP) on SD-OCT after surgery for rhegmatogenous retinal detachment (RRD) repair.

METHODS

One hundred eight eyes of 108 patients who underwent one or more surgeries for RRD were enrolled. The eyes with other maculopathies that were directly related to RRD were excluded. Image acquisition was performed with SD-OCT (Heidelberg Engineering, Germany). Clinical charts were reviewed to assess clinical and surgical findings. Statistical analyses were performed using XLSTAT (Assinsoft, Paris, France).

RESULTS

ERP was found in 9.3% eyes (n = 10). The mean initial visual acuity (logMAR) was 1.34 ± 0.82 in the ERP group compared to 0.49 ± 0.70 in the non-ERP group. PVR was present in 70.0% and chronic macular edema was found in 80.0% of eyes which developed ERP. The mean number of vitreoretinal surgeries in eyes with ERP was 3.3 ± 1.19 and only 1.44 ± 1.02 in eyes without. Silicone oil was used in 60.0% of eyes which developed ERP compared to 13.9% in the non-ERP group.

CONCLUSION

ERP is a late-onset postoperative finding in eyes with RRD and can occur in absence of macular holes. Overall, ERP is more frequent in eyes with complicated courses of RRD including multiple operations, PVR, usage of silicone oil, and chronic macular edema.

Surgical outcomes in patients with lamellar macular holes selected based on the optical coherence tomography consensus definition

Purpose

The surgical indication for lamellar macular holes (LMH) is controversial due to a misclassification of different macular diseases. A consensus based on an optical coherence tomography (OCT) definition has recently been suggested. The aim of this study was to investigate the surgical outcomes of patients with LMH selected based on this OCT-based consensus definition.

Methods

Retrospective review of patients who underwent surgery for LMH with a follow-up of at least 3 months. Anatomical OCT criteria for the diagnosis of LMH were the presence of an irregular foveal contour with foveal cavitation and a loss of retinal tissue. Cases of macular pseudoholes and epiretinal membrane foveoschisis were excluded. Surgery consisted in pars plana vitrectomy with centripetal peri-hole peeling of epiretinal proliferation and internal limiting membrane. Pre- and postoperative visual acuities (VA) were compared, and changes in OCT anatomical features, including the restoration of the foveal profile and outer retinal layers, were assessed.

Results

Eleven eyes of 11 patients were included, of which 9 eyes (81.8%) showed proliferation on preoperative OCT. The mean VA improved from 0.44 ± 0.19 LogMAR (20/55 Snellen equivalent) to 0.16 ± 0.08 LogMAR (20/28 Snellen equivalent), after a mean follow-up of 7.2 ± 2.9 months (P = 0.02). Postoperatively, all eyes showed a restored foveal profile. The mean central foveal thickness increased from 127.6 ± 29.9 μm to 209.0 ± 44.0 μm (P = 0.001). At baseline, ellipsoid zone disruption and external limiting membrane disruption were found in 9 and 7 eyes, respectively. Postoperatively, the ellipsoid zone and external limiting membrane were restored in respectively 6/9 eyes (66.7%) and 5/7 eyes (71.4%). No cases of postoperative full-thickness macular hole were found.

Conclusion

In patients with LMH carefully selected based on the recent OCT-based criteria and showing a loss of retinal tissue, the foveal architecture was restored and the VA was improved after vitrectomy with peri-hole peeling for epiretinal proliferation.

Supplementary information

The online version contains supplementary material available at 10.1186/s40942-021-00297-6.

Multimodal Imaging of Lamellar Macular Holes

Evolution of imaging techniques has renewed interest in the diagnosis of lamellar macular hole (LMH) and greatly implemented the possibilities of gaining more detailed insights into its pathogenesis. Among noninvasive techniques, optical coherence tomography (OCT) is considered the primary examination modality to study LMHs, given its ability to image foveal structure and its widespread availability. OCT also allows to resolve the epiretinal materials associated with LMH, i.e., tractional epiretinal membranes (ERMs) and epiretinal proliferation (EP). En face OCT reconstructions are useful to confirm the foveal abnormalities shown by the eyes with LMH, whereas OCT angiography may reveal alterations of the size and shape of the foveal avascular zone and alterations of the density of the superficial and deep vascular plexuses. On slit-lamp biomicroscopy or fundus camera examination, LMH appears as a round or oval, reddish lesion at the center of the macula, slightly darker than the surrounding retina. The associated tractional ERM, causing wrinkling and glistening of the retinal surface, is usually readily appreciable, whereas EP is hardly apparent on biomicroscopy or fundus photography since the retina surface appears smooth. When imaged with blue fundus autofluorescence (B-FAF) imaging, LMHs are characterized by an increased autofluorescent signal, the intensity of which does not correlate with the thickness of the residual outer retinal tissue. Green reflectance and blue reflectance (BR) images clearly show the increased reflection and wrinkling of the retinal surface caused by tractional ERM associated with LMH. BR and multicolor imaging enable the visualization of EP associated with LMH in the form of a sharply demarcated dark area and in the form of a yellowish area surrounding the hole, respectively. Scarce data regarding invasive imaging techniques, such as fluorescein angiography, for the study of LMH are available in the literature. The aim of this review is to evaluate the contribution that each imaging modality can provide to study the morphologic characteristics of LMH.