Hyperreflective Stress Lines and Macular Holes

[Lamellar macular holes-In the center of vitreomacular interface diseases : Pathophysiology, spontaneous courses and treatment concepts]

BACKGROUND

A lamellar macular hole (LMH) is characterized by a distinct morphologic configuration and can be distinguished from related entities such as macular pseudohole (MPH) and epiretinal membrane with foveoschisis (ERM-FS) by clear morphologic features.

PURPOSE

Based on current knowledge, the pathophysiologic function of LMH in the spectrum of vitreomacular interface diseases will be described and therapeutic concepts will be presented.

METHODS

Current studies are supplemented by case reports to provide a schematic overview of the natural history and therapeutic concepts at the vitreomacular interface.

RESULTS

The LMH is as a retrospective marker for pathologic posterior vitreous detachment in adult patients and may be interpreted as the pathophysiologic center of tractional maculopathies. Various vitreomacular pathologies can result in LMH: a detached vitreomacular traction, a spontaneously closed penetrating macular hole, or an epiretinal membrane with foveoschisis. Pathophysiologically, a degenerative, progressive loss of the architecture of the foveal muller cell cone may be the underlaying mechanism, resulting in the typical undermining of the hole edges and occasionally in a full thickness macular hole. The optimal timing and the appropriate surgical method are the focus of current clinical studies.

CONCLUSION

The pathophysiology of LMH indicates a smooth transition of tractive maculopathies. These should be prospectively evaluated in order to develop evidence-based treatment strategies for LMH.

Myopic macular schisis: Insights into distinct morphological subtypes and novel biomechanical hypothesis

PURPOSE

To analyze the features of myopic macular schisis (MMS) in different retinal layers and to explore the role of Müller cells in the pathophysiology of such condition.

METHODS

Spectral-domain optical coherence tomography (SD-OCT) images of myopic eyes with staphyloma and macular schisis were reviewed. The morphological features of MMS were analyzed and correlated with their geographical location in the parafoveal and perifoveal region. A biomechanical model was adopted to explain MMS morphological differences. The effect of the different schisis subtypes with best corrected visual acuity (BCVA) was also explored.

RESULTS

A total of 36 eyes from 26 patients were included in this study. MMS was classified into inner, middle and outer retinal subtypes. The prevalence of middle retinal schisis was significantly lower in the parafovea, within a central 3 mm-diameter circle (p < 0.001) centered at the fovea . The prevalence of inner retinal schisis was significantly higher outside the central 3-mm diameter circle, in the perifoveal region (p < 0.001). No significant differences were noted in the prevalence of outer retinal schisis for these two locations (p = 0.475). The presence of middle retinal schisis within the central 3-mm diameter circle showed a weak association with lower BCVA (p = 0.058). The presence of outer retinal schisis within the central 3-mm diameter circle was significantly related with lower BCVA (p = 0.024).

CONCLUSION

Three major forms of MMS are distinguished: inner, middle and outer retinal schisis. This classification may have clinical importance as only the outer grade of schisis was associated with vision loss.

NODULAR EPIRETINAL MÜLLER CELL GLIOSIS IN THE FOVEA

PURPOSE

The purpose of this study was to report the findings of a hyperreflective nodular epiretinal gliosis observed with optical coherence tomography presumed to be due to subclinical hyaloidal traction causing Mϋller cell cone gliosis.

METHODS

Retrospective, observational case series.

RESULTS

Six eyes of six patients (mean age: 57 years, range 35-81 years) presented with a nodular epiretinal gliosis and had an average follow-up interval of 26 months (range 1-82 months). The mean baseline best-corrected visual acuity was 0.25 ± 0.17 (Snellen equivalent 20/38.3 ± 16.9). Fundus photography demonstrated a yellowish lesion overlying the fovea. Optical coherence tomography imaging revealed a hyperreflective preretinal lesion with a mean vertical length of 267 μ m (range 185-497) and a mean greatest linear diameter of 312 µ m (range 124-640). There was no vitreoretinal abnormality including vitreomacular traction or epiretinal membrane noted in any eye, and two of six eyes displayed a definitive posterior vitreous detachment. These nodules may have occurred before and persisted even after a posterior vitreous detachment or may have been acquired after the posterior vitreous detachment. The nodules typically remained stable with minimal change although in one eye, a posterior vitreous detachment occurred 6 months after initial presentation and lifted the gliosis off of the retinal surface where it remained attached to the posterior hyaloid.

CONCLUSION

Foveal nodular epiretinal gliosis may occur due to subclinical hyaloidal traction on the Müller cell cone even without obvious vitreoretinal interface abnormality on optical coherence tomography.

Presumed Müller Cell Activation in Multiple Evanescent White Dot Syndrome

Purpose

The purpose of this study was to investigate the foveal changes occurring in multiple evanescent white dot syndrome (MEWDS) using multimodal imaging techniques with a specific focus on hyper-reflective dots (HRDs).

Methods

This was a retro-prospective observational study including 35 eyes with active MEWDS. Structural and en face optical coherence tomography (OCT) was performed, with follow-up visits at 2 weeks, 6 weeks, and 2 months from baseline. HRD percentage area (HRD % area) was calculated in a 600 µm fovea centered circle on en face OCT, after background subtraction and image binarization. HRD % area was compared with 23 fellow control eyes. Longitudinal changes in the HRD % areas were assessed using repeated-measure statistics.

Results

HRDs were observed as scattered hyper-reflective spots on the vitreoretinal interface on en face OCT images, colocalizing with HRDs or vertical hyper-reflective lines on structural OCT images. The baseline evaluation showed a significantly higher HRD % area in MEWDS eyes compared to fellow eyes (0.10 ± 0.03 vs. 0.08 ± 0.04, P = 0.01). The HRD % area correlated positively with LogMAR visual acuity and inversely with the duration of symptoms. Longitudinal analysis revealed a significant reduction in the HRD % area over time. There was no significant interaction between the rate of HRD disappearance and clinical or demographic factors at baseline.

Conclusions

As HRD potentially represents the end-feet projections of activated Müller cells on the retinal surface, this study supports the involvement of Müller cells in the pathogenesis of the disease. The findings highlight the potential of en face OCT imaging for monitoring the progression of MEWDS.

Microstructural changes of photoreceptor layers detected by ultrahigh-resolution SD-OCT in patients with autosomal recessive bestrophinopathy

Purpose

To determine the changes in the microstructures of the photoreceptors in patients with autosomal recessive bestrophinopathy (ARB) by ultrahigh-resolution spectral-domain optical coherence tomography (UHR-SD-OCT).

Methods

Five eyes of 4 patients with ARB were studied. Cross-sectional images of the fovea were recorded by the UHR-SD-OCT system with a depth resolution of <2.0 μm.

Results

The UHR-SD-OCT images revealed changes in the outer retinal structures that were dependent on the severity of the photoreceptor atrophy. There was an increase in the reflectivity and appearance of small hyperreflective dots (HRDs) in the outer segments, followed by an irregularity and decrease in the length of the outer segments, then a disruption of the ellipsoid zone (EZ) band, and appearance of large HRDs corresponding to the segmented ellipsoids. Finally, there was a disappearance of the large HRDs followed by a localized thinning of the outer nuclear layer and appearance of hyperreflective foci above the region of the disrupted EZ.

Conclusions

UHR-SD-OCT can record images that show detailed changes of the microstructures of the photoreceptors at different stages of ARB. These observations should help in determining the mechanisms involved in retinal pathology and should provide important information on the effectiveness of treatments.

Optical coherence tomography findings after surgery for sub-inner limiting membrane hemorrhage due to ruptured retinal arterial macroaneurysm

Ruptured retinal arterial macroaneurysm (RAM) can cause sub-inner limiting membrane (ILM) hemorrhage, leading to acute vision loss in the elderly. Vitrectomy has been established as an effective treatment to remove hemorrhage and facilitate visual recovery. Although optical coherence tomography (OCT) is useful for the diagnosis of sub-ILM hemorrhage before surgery, little is known about the postoperative OCT findings. Here, we retrospectively investigated the records of nine eyes of nine patients who underwent surgery for sub-ILM hemorrhage due to RAM rupture. On postoperative OCT, hyperreflectivity throughout the full thickness of the central fovea was observed in eight eyes (88.9%), and disruption of the ellipsoid/interdigitation zone (EZ/IZ) was observed in seven out of eight eyes (87.5%). The widths of the hyperreflectivity and EZ disruption gradually decreased. Visual recovery was least favorable in two eyes, in which the EZ line continuation did not recover until the final follow-up. The OCT findings corresponded to the hemorrhagic staining identified on fundus photographs in at least four eyes; as per the fundus photographs the findings persisted even after the hemorrhage was absorbed. In contrast, the OCT findings resembled the appearance before the development of a full-thickness macular hole, suggesting fragility caused by the RAM rupture.

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.

Full-Thickness Macular Hole Due to Choroidal Neovascularization in the Setting of Pathologic Myopia

Purpose: To present a case of myopic choroidal neovascularization (CNV) leading to a full-thickness macular hole (MH) in a patient with macular schisis. Methods: A single case was evaluated. Results: A 65-year-old woman presented with myopic staphyloma and foveoschisis in both eyes. One month after the baseline presentation for myopic macular schisis, the patient presented with a paracentral scotoma in the left eye. Examination showed a submacular hemorrhage in the left eye. Optical coherence tomography of the left eye showed subretinal fluid and subretinal hyperreflective material in the fovea, suggestive of exudative myopia, and a small full-thickness MH (diameter 86 µm). After anti-vascular endothelial growth factor injections, the CNV showed interval improvement; however, a larger full-thickness MH (diameter 287 µm) developed in the left eye. Conclusions: A full-thickness MH developed secondary to CNV, leading to foveal dehiscence in an eye with baseline macular schisis.

Detailed analyses of microstructure of photoreceptor layer at different severities of occult macular dystrophy by ultrahigh-resolution SD-OCT

Purpose

To analyze the microstructures of the photoreceptor layer in detail in eyes with occult macular dystrophy (OMD, Miyake's disease) by ultrahigh-resolution spectral-domain optical coherence tomography (UHR-SD-OCT).

Observations

Twenty-eight normal subjects and 5 patients with OMD of different severities were studied. Cross-sectional images through the fovea were recorded with a UHR-SD-OCT system with a depth resolution of <2.0 μm. In patients with OMD, the UHR-SD-OCT images revealed abnormal photoreceptor microstructures which were not detected in the conventional SD-OCT images. The UHR-SD-OCT images showed that the interdigitation zone (IZ) was not present and the outer segments were hyperreflective with hyperreflective dots (HRDs) aligned like string of pearls during the earlier stages. There was a disruption of the ellipsoid zone (EZ) which appeared as clusters of larger HRDs, and these HRDs became less apparent with increasing time. The outer segments became hyporeflective and rod IZ became apparent with longer duration of the disease process.

Conclusions and Importance

The UHR-SD-OCT images show detailed characteristics of the photoreceptor microstructures of different severities during the progression of OMD. These detailed observations will help in understanding the mechanisms involved in the retinal pathology and should provide important information for their treatments.

Human Foveal Cone and Müller Cells Examined by Adaptive Optics Optical Coherence Tomography

Purpose

The purpose of this study was to image and investigate the foveal microstructure of human cone and Müller cells using adaptive optics-optical coherence tomography.

Methods

Six healthy subjects underwent the prototype adaptive optics-optical coherence tomography imaging, which allowed an axial resolution of 3.4 µm and a transverse resolution of approximately 3 µm. The morphological features of the individual retinal cells observed in the foveola were qualitatively and quantitatively evaluated.

Results

In the six healthy subjects, the image B-scans showed hyper-reflective dots that were densely packed in the outer nuclear layer. The mean number, diameter, and density of hyper-reflective dots in the foveola were 250.8 ± 59.6, 12.7 ± 59.6 µm, and 6966 ± 1833/mm2, respectively. These qualitative and quantitative findings regarding the hyper-reflective dots were markedly consistent with the morphological features of the foveal cone cell nuclei. Additionally, the images showed the funnel-shaped hyporeflective bodies running vertically and obliquely between the inner and external limiting membranes, illustrating the cell morphology of the foveal Müller cells.

Conclusions

Using adaptive optics, we succeeded in visualizing cross-sectional images of the individual cone and Müller cells of the human retina in vivo.

Translational Relevance

Adaptive optics-optical coherence tomography would help to improve our understanding of the pathogenesis of macular diseases.

Spontaneous macular hole closure after posterior vitreous detachment in an eye with hyperreflective OCT stress line

PURPOSE

The aim of this report is to describe a patient who presented with a central hyper-reflective line (HRL) with spectral domain-optical coherence tomography (SD-OCT) after posterior vitreous detachment that evolved to full thickness macular hole (FTMH) with subsequent spontaneous resolution.

OBSERVATIONS

A 59-year-old patient presented with a history of photopsia and floaters followed by the development of a central scotoma in the right eye (OD). The left eye (OS) was normal. On examination, visual acuity (VA) was 20/20- OD and 20/20 OS. Retinal examination OD was remarkable for a retinal tear, and SD-OCT demonstrated a central HRL. The patient underwent laser retinopexy to barricade the retinal tear. Sequential SD-OCT of the macula was performed and the patient eventually developed a small FTMH 8 months after the baseline presentation. VA was correspondingly reduced to 20/80 OD. Upon return after 4 months, the hole was completely resolved with improvement of VA to 20/20 OD.

CONCLUSION

Vitreomacular traction (VMT) may lead to foveal dehiscence. This instability can be detected with SD-OCT as a vertical hyperreflective stress line that is a risk factor for progression to a FTMH. With release of VMT, FTMH can spontaneously close.

Foveal crack sign as a predictive biomarker for development of macular hole in fellow eyes of patients with full-thickness macular holes

To investigate the prevalence and predictive value of the foveal crack sign (FCS) in fellow eyes of patients with full-thickness macular holes (FTMH) regarding future macular hole (MH) formation. In a retrospective observational case series, 113 fellow eyes of 113 patients with FTMH have been observed during a mean follow-up time of 21 months. According to baseline SD-OCT images, patients were divided into 4 separate groups: patients with FCS and vitreous adhesion, patients with FCS and vitreous detachment, patients without FCS with vitreous adhesion, patients without FCS with vitreous detachment. Progression rate to MH formation, predictive value of FCS and of vitreous interface status were calculated and compared across the four groups. FCS was observed in 19 of 113 fellow eyes (17%) of patients with FTMH, 10 of them with progression to MH during the mean follow up time of 21 months. 2 other eyes with progression to MH showed no FCS at baseline. Progression rate was shown to be 77% (10 of 13 eyes) in patients with FCS and vitreous adhesion, 0% (none of 6 eyes) in patients with FCS and vitreous detachment, 4% (2 of 48 eyes) in patients without FCS with vitreous adhesion, 0% (none of 46 eyes) in patients without FCS with vitreous detachment. FCS had sensitivity of 83.3% (95% CI 50.9–97.1%) and specificity of 91.1% (95% CI 83.3–95.6%) in predicting MH formation, positive predictive value of FCS was 52.6% (95% CI 29.5–74.8%) and negative predictive value 97.9% (95% CI 91.8–99.6%). Having simultaneously FCS and vitreous adhesion showed 83.3% (95% CI 50.9–97.1%) sensitivity and 97.1% (95% CI 91.1–99.2%) specificity in predicting macular hole formation; positive predictive value was 76.9% (95% CI 46.0–93.8%) and negative predictive value was 98.0% (95% CI 92.4–99.7%). Fellow eyes of patients with FTMH with foveal crack sign are at a very high risk (77%) of FTMH development, as long as posterior vitreous adhesion is present.