Interfaces

Vitreomacular interface abnormalities in the Ghanaian African

BACKGROUND/OBJECTIVE

Describe vitreomacular interface abnormalities (VMIA) using spectral-domain optical coherence tomography (SD-OCT), and correlations with age-related macular degeneration (AMD) grade in Ghanaian Africans.

SUBJECTS/METHODS

Prospective, cross-sectional study of adults aged ≥50 years recruited in Ghana AMD Study. Participant demographics, medical histories, ophthalmic examination, digital colour fundus photography (CFP) were obtained. High-resolution five-line raster OCT, Macular Cube 512 × 128 scans, and additional line scans in areas of clinical abnormality, were acquired. SD-OCT VMI features classified by International Vitreomacular Traction Study Group system and relationships to AMD grade were evaluated.

OUTCOMES

VMIA prevalence, posterior vitreous detachment (PVD), vitreomacular adhesions (VMA), vitreomacular traction (VMT), epiretinal membranes (ERM), correlations with AMD grade.

RESULTS

The full Ghana AMD cohort included 718 participants; 624 participants (1248 eyes) aged ≥50 years (range = 50-101, mean = 68.8), 68.9% female were included in this analysis. CFP with OCT scans were available for 776 eyes (397 participants); 707 (91.1%) had gradable CFP and OCT scans for both AMD and VMI grading forming the dataset for this report. PVD was absent in 504 (71.3%); partial and complete PVD occurred in 16.7% and 12.0% respectively. PVD did not increase with age (p = 0.720). VMIA without traction and macular holes were observed in 12.2% of eyes; 87.8% had no abnormalities. VMIA was not significantly correlated with AMD grade (p = 0.819).

CONCLUSIONS

This provides the first assessment of VMIA in Ghanaian Africans. VMIA are common in Africans; PVD may be less common than in Caucasians. There was no significant association of AMD grade with VMIA.

Spontaneous posterior vitreous detachment: A glance at the current literature

Spontaneous posterior vitreous detachment (PVD) is a common age-related condition in which prevalence tends to increase with age. Acute PVD can cause the onset of symptoms that include visual disturbances, myodesopsia and photopsia. The goal of this short review was to provide a quick glance at the important factors related to PVD based on current literature in this field, which includes incidence, symptoms, diagnosis, risk factors, and education for patients with acute symptoms, and treatments. The take home message is that an ophthalmic examination at the onset of symptoms is of utmost importance, considering that irreversible sight-threatening complications can be prevented if diagnosed and treated promptly.

Recurrent Vitreomacular Traction in a Patient Treated with Ocriplasmin: A Case Report

INTRODUCTION

To describe a case of recurrent vitreomacular traction and macular edema that appeared both before and after the intravitreal injection of ocriplasmin.

CASE REPORT

An 82-year-old monocular man presented with metamorphopsia and reduced vision of 1-week duration. The patient's general medical history was unremarkable. His ophthalmic history was significant for severe ocular trauma in the right eye in childhood that caused phthisis. The left eye had undergone uncomplicated phacoemulsification 3 months earlier and the 1-month postoperative best corrected visual acuity (BCVA) was logarithmic mean angle of resolution (logMAR) 0.0. There was no history of other ocular conditions. At presentation, BCVA was logMAR 0.2 and optical coherence tomography (OCT) revealed the presence of cystoid macular edema caused by vitreomacular traction (VMT). The patient was scheduled for intravitreal ocriplasmin injection. Prior to treatment, the vision improved spontaneously to logMAR 0.1, and no VMT could be detected with spectral domain (SD)-OCT. The ocriplasmin injection was deferred but 3 weeks later the patient presented again with metamorphopsia, while VMT was again evident on SD-OCT. Ocriplasmin was injected and 1 month later the BCVA reached logMAR 0.1 without VMT. However, at 2 months post injection the VMT reappeared and a conservative approach with observation and topical nepafenac administration was decided. At the 3-month post-injection visit there was no VMT. More than 3 years after the ocriplasmin injection there is still no evidence of VMT, the patient is free of metamorphopsia, and his BCVA is logMAR 0.0.

CONCLUSION

Separation of consecutive layers of the vitreous cortex (vitreoschisis) may account for recurrent VMT.

Matrix Metalloproteinases in Age-Related Macular Degeneration (AMD)

Age-related macular degeneration (AMD) is a complex, multifactorial and progressive retinal disease affecting millions of people worldwide. In developed countries, it is the leading cause of vision loss and legal blindness among the elderly. Although the pathogenesis of AMD is still barely understood, recent studies have reported that disorders in the regulation of the extracellular matrix (ECM) play an important role in its etiopathogenesis. The dynamic metabolism of the ECM is closely regulated by matrix metalloproteinases (MMPs) and the tissue inhibitors of metalloproteinases (TIMPs). The present review focuses on the crucial processes that occur at the level of the Bruch’s membrane, with special emphasis on MMPs, TIMPs, and the polymorphisms associated with increased susceptibility to AMD development. A systematic literature search was performed, covering the years 1990–2020, using the following keywords: AMD, extracellular matrix, Bruch’s membrane, MMPs, TIMPs, and MMPs polymorphisms in AMD. In both early and advanced AMD, the pathological dynamic changes of ECM structural components are caused by the dysfunction of specific regulators and by the influence of other regulatory systems connected with both genetic and environmental factors. Better insight into the pathological role of MMP/TIMP complexes may lead to the development of new strategies for AMD treatment and prevention.

Vitreous and Vision Degrading Myodesopsia

Macromolecules comprise only 2% of vitreous, yet are responsible for its gel state, transparency, and physiologic function(s) within the eye. Myopia and aging alter collagen and hyaluronan association causing concurrent gel liquefaction and fibrous degeneration. The resulting vitreous opacities and collapse of the vitreous body during posterior vitreous detachment are the most common causes for the visual phenomenon of vitreous floaters. Previously considered innocuous, the vitreous opacities that cause floaters sometimes impact vision by profoundly degrading contrast sensitivity function and impairing quality-of-life. While many people adapt to vitreous floaters, clinically significant cases can be diagnosed with Vision Degrading Myodesopsia based upon echographic assessment of vitreous structure and by measuring contrast sensitivity function. Perhaps due to the ubiquity of floaters, the medical profession has to date largely ignored the plight of those with Vision Degrading Myodesopsia. Improved diagnostics will enable better disease staging and more accurate identification of severe cases that merit therapy. YAG laser treatments may occasionally be slightly effective, but vitrectomy is currently the definitive cure. Future developments will usher in more informative diagnostic approaches as well as safer and more effective therapeutic strategies. Improved laser treatments, new pharmacotherapies, and possibly non-invasive optical corrections are exciting new approaches to pursue. Ultimately, enhanced understanding of the underlying pathogenesis of Vision Degrading Myodesopsia should result in prevention, the ultimate goal of modern Medicine.

Anomalous Vitreoretinal Adhesions in Patients with Exudative Age-Related Macular Degeneration: An OCT Study

Purpose

To analyze the relationship between the retina and the vitreous in patients with exudative age-related macular degeneration (ARMD).

Methods

Consecutive patients with exudative ARMD, proven by fluorescein angiography, were recruited. Fundus biomicroscopic examination, color and red-free fundus photographs, and serial scans of the macular region using optical coherence tomography (OCT3, Carl Zeiss) were performed before and after photo dynamic therapy (PDT) with verteporfin (Visudyne, Novartis Ophthalmics). Vitreoretinal relationships have been described and compared with fundus photographs and data of fundus biomicroscopy examination.

Results

Sixty-six eyes of 52 consecutive patients (33 women, 19 men; mean age 75 years, range 64 to 89 years) with exudative ARMD were studied. Analysis of serial OCT scans showed that 13 eyes (20%) did not present any visible vitreous structures. Two eyes (3%) had the appearance of a complete posterior vitreous detachment (PVD). Fifty-one eyes (77%) exhibited some abnormalities of the vitreoretinal interface including 12 eyes with epiretinal membrane and retinal thickening and distortion. Among the 39 eyes examined before and after PDT with Visudyne, only 3 eyes developed a partial vitreous detachment and 1 eye progressed to a complete PVD.

Conclusions

Eyes with exudative ARMD exhibit a high prevalence of abnormalities of the vitreoretinal interface similar to that observed in many chronic inflammatory diseases. PDT with verteporfin does not modify the observed vitreoretinal adhesions.

[A porous coral-like structure - a new insight into the morphology of the inner limiting membrane of the retina?]

To date, the internal limiting membrane (ILM), specifically, the side facing the retina, has never been studied by two parallel, mutually complementary methods. This is an attempt to explain favorable results of ILM peeling in various macular pathologies.

AIM

By employing scanning (SEM) and transmission electron microscopy (TEM), to identify morphological features of epiretinal samples removed during vitrectomy in patients with lamellar macular hole (LMH) or epiretinal membrane (ERM).

MATERIAL AND METHODS

We studied 23 eyes of 23 patients divided into two groups. The first group (13 samples, 11 eyes) consisted of patients with LMH; the second (12 samples, 12 eyes) - with ERM. The surgeries yielded a total of 21 epiretinal samples peeled simultaneously with the ILM and 4 epiretinal samples (2 eyes) peeled in two parts, the second part containing the ILM. One half of the samples was studied by SEM without prior dehydratation, the other - by TEM.

RESULTS

The study revealed a high degree of ultrastructural similarity between the two groups of ILM samples. Judging from SEM findings, two sides of the membrane were clearly identified. Porous coral-like structures (PCS) were discovered on the side facing the retina. TEM in the area of PCS discovered parallel arrangement of multiple Muller cell (MC) bodies and processes separated by wide layers of the intercellular matrix. The vitreal side of all ILM samples was notable for numerous fibroblast-like cells. Many variously shaped petrified structures were found on both sides of the membrane.

CONCLUSION

During the so called ILM peeling, the surgeon removes a layered structure that includes the basal membrane of MC, cells and fibers attached to its vitreal side, and one more layer comprised by PCS and rather readily torn off from the main massif. The functional significance of this previously unknown structure as well as the effect of its partial removal during surgical manipulations with neurosensory retina in the macular region is yet to be investigated.

The vitreomacular interface in different types of age-related macular degeneration

AIM

To evaluate the vitreomacular interface in cases with wet age-related macular degeneration (AMD) and to compare them to eyes with dry AMD and normal eyes.

METHODS

This was a cross-sectional comparative study that included 87 eyes with wet AMD, 42 eyes with dry AMD and 40 eyes without AMD as a control group. Optical coherence tomography (OCT) examination was performed for all patients to assess the vitreomacular interface.

RESULTS

In the wet AMD group, 34.5% of cases had vitreomacular adhesion (VMA). Only 14.3% of dry AMD cases and 10% of control cases had VMA. There was a significant difference between the control group and the wet AMD group (P=0.004) as well as the dry and wet AMD group (P=0.017). There was also a significant difference between the incidence of VMA in patients with subretinal choroidal neovascularization (CNV, type 1) and intraretinal CNV (type 2 or type 3) (P=0.020).

CONCLUSION

There is an association between posterior vitreous attachment and AMD. There is also an increased incidence of VMA with intra-retinal CNV.

Age-related macular degeneration and changes in the extracellular matrix

Age-related macular degeneration (AMD) is the leading cause of permanent, irreversible, central blindness (scotoma in the central visual field that makes reading and writing impossible, stereoscopic vision, recognition of colors and details) in patients over the age of 50 years in European and North America countries, and an important role is attributed to disorders in the regulation of the extracellular matrix (ECM). The main aim of this article is to present the crucial processes that occur on the level of Bruch’s membrane, with special consideration of the metalloproteinase substrates, metalloproteinase, and tissue inhibitor of metalloproteinase (TIMP).

A comprehensive review of the literature was performed through MEDLINE and PubMed searches, covering the years 2005–2012, using the following keywords: AMD, extracellular matrix, metalloproteinases, tissue inhibitors of metalloproteinases, Bruch’s membrane, collagen, elastin.

In the pathogenesis of AMD, a significant role is played by collagen type I and type IV; elastin; fibulin-3, -5, and -6; matrix metalloproteinase (MMP)-2, MMP-9, MMP-14, and MMP-1; and TIMP-3. Other important mechanisms include: ARMS2 and HTR1 proteins, the complement system, the urokinase plasminogen activator system, and pro-renin receptor activation.

Continuous rebuilding of the extracellular matrix occurs in both early and advanced AMD, simultaneously with the dysfunction of retinal pigment epithelium (RPE) cells and endothelial cells. The pathological degradation or accumulation of ECM structural components are caused by impairment or hyperactivity of specific MMPs/TIMPs complexes, and is also endangered by the influence of other mechanisms connected with both genetic and environmental factors.

Vitreoretinal interface in central serous choroidopathy: a retrospective case-control study

PURPOSE

To investigate the frequency and patterns of vitreoretinal adherence in central serous choroidopathy (CSC) using spectral domain optical coherence tomography (SD-OCT) imaging and compare them with normal subject.

METHODS

A descriptive observational analytical retrospective case-control study. The study patients were split into non-chronic and chronic CSC groups and compared with an age- and gender-matched control group composed of healthy individuals without CSC. Five patterns of vitreoretinal adherence were defined: lacunae, partial posterior vitreous detachment (partial-PVD), epiretinal membrane (ERM), focal vitreomacular adherence (VMA) and no recognizable pattern. Statistical analysis was performed.

RESULTS

One hundred and four eyes of 52 patients were included in this study. Forty-eight eyes of 24 patients had chronic CSC and 56 eyes of 28 patients had non-chronic CSC. The control group for chronic CSC included 96 normal eyes of 48 subjects, and the control group for non-chronic CSC included one hundred and twelve normal eyes of 56 subjects. We found a recognizable pattern of the vitreoretinal interface (lacuna, partial-PPV, VMA or ERM) more often in non-chronic CSC (p = 0.0001, OR = 6.51 and CI = 2.71-15.62) and in chronic CSC patients (p = 0.001, OR = 4.05, CI: 1.77-9.57) than in normal subjects.

CONCLUSION

The proportion of patterns of vitreoretinal adherence and interface found in CSC changes with age and manifests differently compared with normal eyes. The results indicate early changes in CSC patients younger than 40 years of old bilaterally.

Vitreomacular traction and exudative age-related macular degeneration

Vitreomacular traction resulting from lacking, incomplete or anomalous posterior vitreous detachment is suspected to play a crucial role in the pathogenesis of different forms of age-related macular degeneration (AMD) along with the known mechanisms. It is probable that the fundamental pathomechanisms of AMD formation have already begun by the time tractional forces lead to a change for the worse. Vitreomacular traction alone is perhaps not able to induce AMD. It would seem sensible to consider vitreous changes when diagnosing and treating AMD patients because of the high coincidence of vitreomacular traction and choroidal neovascularization (CNV) and the often successful treatment of other diseases of the vitreoretinal interface by vitrectomy. The concept of the pathogenesis of AMD should therefore be extended to include the influence of the vitreous, especially where therapeutic concepts such as pharmacological vitreolysis and vitreous separation have been established as causative treatment of late forms of AMD.

Posterior vitreomacular adhesion: a potential risk factor for exudative age-related macular degeneration?

PURPOSE

To compare the state of the posterior vitreous in exudative age-related macular degeneration (AMD) with eyes with nonexudative AMD and controls.

DESIGN

Prospective, observational case series.

METHODS

B-scan ultrasonography and optical coherence tomography (OCT) were performed in 163 eyes from 82 subjects older than 55 years, 50 eyes with exudative AMD, 57 with nonexudative AMD, and 56 control eyes. Main outcome measures were the number of eyes with complete posterior vitreous detachment (PVD) by ultrasound and the number of eyes with central vitreomacular adhesion by OCT.

RESULTS

By ultrasonography, 17 (34.0%) of 50 eyes with exudative AMD had PVD as compared with 41 (71.9%) of 57 eyes with nonexudative AMD (P = .00002) and 34 (60.7%) of 56 controls (P = .017). OCT detected persistent central vitreoretinal adhesion surrounded by a detached posterior vitreous cortex in 18 (36%) of 50 eyes with exudative AMD, significantly higher than in nonexudative AMD (4/57 [7%]; P < .0001) and in controls (6/56 [10%]; P = .002).

CONCLUSIONS

Persistent attachment of the posterior vitreous cortex to the macula may be another risk factor for the development of exudative AMD via vitreoretinal traction inducing chronic low-grade inflammation, by maintaining macular exposure to cytokines or free radicals in the vitreous gel, or by interfering in transvitreous oxygenation and nutrition of the macula. Inducing PVD may provide prophylactic benefit against exudative AMD.

Anomalous posterior vitreous detachment: a unifying concept in vitreo-retinal disease

Posterior vitreous detachment (PVD) is the consequence of changes in the macromolecular structure of gel vitreous that result in liquefaction, concurrent with alterations in the extracellular matrix at the vitro-retinal interface that allow the posterior vitreous cortex to detach from the internal limiting lamina of the retina. Gel liquefaction that exceeds the degree of vitro-retinal dehiscence results in anomalous PVD (APVD). APVD varies in its clinical manifestations depending upon where in the fundus vitreo-retinal adhesion is strongest. At the periphery, APVD results in retinal tears and detachments. In the macula, APVD causes vitreo-macular traction syndrome, results in vitreoeschisis with macular pucker or macular holes, or contributes to some cases of diabetic macular edema. At the optic disc and retina, APVD causes vitreo-papillary traction and promotes retinal and optic disc neovascularization. Unifying the spectrum of vitreo-retinal diseases into the conceptual frame-work of APVD underscores that to more effectively treat, and ultimately prevent, these disorders it is necessary to replicate the two components of an innocuous PVD, i.e., gel liquefaction and vitreo-retinal dehiscence. Pharmacologic vitreolysis is designed to mitigate against APVD by chemically breaking down vitreous macromolecules and weakening vitro-retinal adhesion to safely detach the posterior vitreous cortex. This would not only facilitate surgery, but if performed early in the natural history of disease, it should prevent progressive disease.

Age-related changes in vitreous mobility as measured by video B scan ultrasound

Many vitreoretinal disorders increase in incidence with age. The vitreous is known to liquefy and separate from the retina in aging patients. Liquefaction and partial vitreous separation alter the biomechanics of the vitreous and change the tractional forces exerted by the vitreous on the retina. These forces may play a role in the development of a variety of vitreoretinal pathologies including retinal tears, cystoid macular edema, and macular holes. The purpose of this study is to test the hypothesis that the biomechanical properties of the vitreous change with aging and can be quantified by analysis of kinetic B scan ultrasound recordings. Kinetic B scan ultrasound recordings were made of the vitreous gel of 38 subjects from ages 18 to 91 during standard eye motions. The recordings were graded for speckle density (hyperreflective areas on ultrasound) and were examined for the presence or absence of posterior vitreous detachment. Tracking of the speckles on a polar grid allowed for the calculation of the angle travelled by the speckle relative to the angle travelled by the eye. The recordings were also analysed for "overshoot time", or the amount of time that the speckles continued to travel after the cessation of eye movement. The vitreous of subjects of age less than 46 years demonstrated significantly less speckle density (P < 0.001), less overshoot time (P < 0.001), and less angle travelled by the speckle relative to the angle travelled by the eye when compared to older subjects (P = 0.006). The presence or absence of PVD as diagnosed by kinetic ultrasound was not a significant predictor for speckle density, overshoot time, or ratio of angular motions. The results indicate that aging affects the biomechanics of the vitreous in ways which can be quantified with kinetic ultrasound analysis using the grading system described above.