Hyaline Research Articles

Chronic macular edema associated with extrafoveal vitreoretinal traction.

To describe an association between extrafoveal vitreoretinal traction and chronic macular edema, either diffuse (DiME) or cystoid (CME), by the use of optical coherence tomography (OCT). Charts and OCT findings of two patients with persistent DiME or persistent DiME accompanied by CME, both associated with extrafoveal vitreous traction membranes were analyzed. Excluded were eyes that either had another vitreoretinopathy that could affect the analysis, had undergone pars plana vitrectomy or that had been treated by intravitreal medications. An age-matched normal control group for OCT (n=12) allowed for the quantification of the normal macular thicknesses. One patient (one eye) following perforating ocular injury and one patient (one eye) of idiopathic origin, both with chronic macular edema refractive to conventional treatment, were found to be associated with extrafoveal vitreoretinal traction in each eye. Retinal edema that was underlying the traction site in each eye was in continuum with the central macular edema, thus manifesting as diffuse macular edema. The automatic central 6-radial lines program in the OCT enabled the detection of the traction site in one eye, while in the other eye the diagnosis was achieved only with the additional use of the Line group program. Chronic diffuse macular edema might be related to extrafoveal vitreoretinal traction. Careful search with the diverse OCT programs should be made in order to detect extrafoveal traction sites. Further studies and a larger cohort are required to compare the efficacy of early vitrectomy or pharmacologic vitreolysis versus the current therapeutic approaches in these situations.

O uso de técnica eletroquímica para a descontaminação de estruturas cerâmicas vítreas porosas

Apresentamos neste trabalho os resultados de ensaios preliminares para avaliar o uso de técnica de eletro-osmose para a remoção de contaminantes orgânicos em estruturas porosas cerâmicas, como filtros ou similares. A técnica consiste em forçar a migração de contaminantes retidos na estrutura interna ou na superfície dos poros por meio da aplicação de tensão controlada em célula eletroquímica projetada para este fim. As moléculas absorvidas na superfície cerâmica estarão sujeitas as ações cisalhantes de uma camada aquosa difusa móvel, e uma vez na condição iônica, migram na direção do campo de carga oposta, sendo posteriormente removidas. Nos ensaios de avaliação da técnica, escolhemos o fenol como contaminante padrão e os testes realizados em membranas vítreas microporosas imersas em solução aquosa. Os dados foram obtidos em função do tempo de aplicação da carga por medidas de densidade ótica e concentração de hidrogenação. Os resultados indicam remoções proporcionais a 70% do contaminante em estado diluído após 120 min de aplicação de carga.

Visual prognosis and macular pathology in eyes with retinal macroaneurysms

We studied retrospectively the visual outcome of 20 eyes of 19 patients with symptomatic retinal arterial macroaneurysm. The macular pathology responsible for the acute visual loss was categorized as macular edema (5 eyes), preretinal hemorrhages alone (3 eyes), subretinal hemorrhages with or without preretinal hemorrhages (10 eyes) and vitreous hemorrhage (2 eyes). Thirteen eyes were treated with argon or dye laser photocoagulation. Five eyes with preretinal hemorrhage underwent YAG laser photodisruption of the posterior hyaloid membrane to release the preretinal hemorrhage into the vitreous space. Five eyes with macular edema, 3 eyes with preretinal hemorrhage without subretinal hemorrhage and 2 eyes with vitreous hemorrhage showed final vision of 0.5 or better, but of the other 10 eyes with subretinal hemorrhage with or without preretinal hemorrhage, 9 showed final visual acuity of 0.2 or worse. Visual prognosis of submacular hemorrhage due to ruptured retinal macroaneurysm is poor, but that of macular edema, preretinal hemorrhage or vitreous hemorrhage is relatively good.

Macular holes: clinical research and therapeutic efficacy

Macular hole is a retinal hole locates in macular fovea, and can be idiopathic, traumatic and high myopic. Although its etiology, disease course, treatment and prognosis varied from case to case,enforcing macular-hole closure and retinal reattachment are challenges to all cases. Completely removal of premacular vitreous cortex is the key to successful repair, and inner limiting membrane (ILM) staining and peeling can greatly help the removal of those cortexes. Selections and usages of different dyes, methods of ILM peeling, and strategies to promote macular retina-choroidal adhesion warrant further study to improve treatment and prognosis of macular holes. Key words: Retinal perforations/pathology; Retinal perforations/therapy; Vitrectomy; Editorial

Affects of plain boiled water (H2O) mixed with pure natural honey (Mel) in inflammation of the kidney (Nephritis)

Purpose of this clinical research study was, to determine the efficacy of plain water mixed with pure natural honey, to be used in the inflammation of the kidney (Nephritis) patients. 10 patients aged 18 to 21 years, (4 females, 6 males) with non- sever nephritis were given[three times a day] one standard glass of plain boiled water mixed with 4-table spoons of pure natural honey (Mel) for 14 days. Study was conducted at Herbs Research Foundation of Pakistan (Okara) during December 2003. Pre - clinical trials, 5 days wash out period were given, patients medical condition were assessed through Urinalysis. After 14 days of study, significant decrease of albumin, protein, pus, blood, red and white blood cells and hyaline in patients urinalysis were noted, (while one patient (male) did not respond well). The study provides convincing evidence that plain boiled water mixed with pure natural honey could be used in nephritis patients successfully.

High-resolution, three-dimensional, and contrast-enhanced ultrasonographic findings in diseases of the eye

Objectives To review the contrast-enhanced ultrasound (CEUS) and 3D ultrasound findings (3D-US) in various pathologies involving the eye and orbit and to compare them with high-resolution US (HRUS) findings. Background CEUS is a valid diagnostic tool for study several districts. There are numerous pathological conditions of the eye in which CEUS can be very helpful or detrimental. Image Findings We review a wide range of ocular lesions, traumatic (retinal and choroidal detachments) and malignant (choroidal melanoma, tumors inside and outside the muscle cone) evaluated alternatively with CEUS and 3D and compare these findings with those obtained with HRUS. Dysthyroid orbitopathy is not included in this review. Conclusion CEUS plays a central role in the differentiation of detached retina (vascular) and vitreous membranes (avascular). It is also helpful in the assessment of tumor of the eye, in planning treatment for choroidal melanoma, and in assessing orbital masses for neovascularization. HRUS is highly effective in the detection of traumatic and non-traumatic lesions of the eye, but it is less effective for the assessment of orbital lesions. The 3D module has increased the diagnostic value of CEUS. CEUS is cost-effective and can be used when CT and MR cannot be performed.

Vitreopapillary Traction Diagnosed by Spectral Domain Optical Coherence Tomography

This report describes a case of vitreopapillary traction with right inferior altitudinal defect similar to anterior ischemic optic neuropathy. A 35-year-old man with inferior altitudinal defect in his right eye was referred. The right optic disc was elevated and the superior disc margin was blurred. Spectral domain optical coherence tomography (SD-OCT) of the right optic disc showed the vitreous cortex was highly reflective and pulling the optic disc margin superiorly. The posterior hyaloid membrane on the nasal side of the optic disc was less reflective than that superior to the disc, suggesting that vitreopapillary traction contributed to this condition. During a careful 12-month observation, no change was noted in the optic disc appearance or visual field. Thus, SD-OCT was useful in visualizing the posterior hyaloid membrane and was helpful in the diagnosis of vitreopapillary traction syndrome.

Metabolic physiology in age related macular degeneration

Ischemia and hypoxia have been implicated in the pathophysiology of age related macular degeneration (AMD). This has mostly been based on studies on choroidal perfusion, which is not the only contributor to retinal hypoxia found in AMD eyes. Other features of AMD may also interfere with retinal oxygen metabolism including confluent drusen, serous or hemorrhagic retinal detachment, retinal edema and vitreoretinal adhesion. Each of these features contributes to retinal hypoxia: the drusen and retinal elevation by increasing the distance between the choriocapillaris and retina; vitreoretinal adhesion by reducing diffusion and convection of oxygen towards and vascular endothelial growth factor (VEGF) away from hypoxic retinal areas. Hypoxia-inducible-factor is known to exist in subretinal neovascularization and hypoxia is the main stimulus for the production of VEGF. Each feature may not by itself create enough hypoxia and VEGF accumulation to stimulate wet AMD, but they may combine to do so. Choroidal ischemia in AMD has been demonstrated by many researchers, using different technologies. Choroidal ischemia obviously decreases oxygen delivery to the outer retina. Confluent drusen, thickening of Bruch's membrane and any detachment of retina or retinal pigment epithelium, increases the distance between the choriocapillaris and the retina and thereby reduces the oxygen flux from the choroid to the outer retina according to Fick's law of diffusion. Retinal elevation and choroidal ischemia may combine forces to reduce choroidal oxygen delivery to the outer retina, produce retinal hypoxia. Hypoxia leads to production of VEGF leading to neovascularization and tissue edema. A vicious cycle may develop, where VEGF production increases effusion, retinal detachment and edema, further increasing hypoxia and VEGF production. Adhesion of the viscous posterior vitreous cortex to the retina maintains a barrier to diffusion andconvection currents in the vitreous cavity according to the laws of Fick's, Stokes-Einstein and Hagen-Poiseuille. If the vitreous is detached from the surface of the retina, the low viscosity fluid transports oxygen and nutrients towards an ischemic area of the retina, and cytokines away from the retina, at a faster rate than through attached vitreous gel. Vitreoretinal adhesion can exacerbate retinal hypoxia and accumulation of cytokines, such as VEGF. Vitreoretinal traction can also cause hypoxia by retinal elevation. Conceivably, the basic features of AMD, drusen, choroidal ischemia, and vitreoretinal adhesion are independently determined by genetics and environment and may combine in variable proportions. If the resulting hypoxia and consequent VEGF accumulation crosses a threshold, this will trigger effusion and neovascularization.

Depiction of the vitreous pocket by optical coherence tomography

The reported shape and size of the vitreous pocket vary depending on the method of visualization. We used spectral domain optical coherence tomography (SD-OCT) to clarify the structure of the normal vitreous pocket. The macular retina of 20 consecutive non-highly myopic eyes of 10 healthy young adults (aged 22-27 years) was examined using spectral SD-OCT. The premacular vitreous pocket and the pre-papillary Cloquet's canal were observed in a scan area 9 mm in transverse diameter and 6 mm in longitudinal diameter. On SD-OCT, the vitreous pocket was observed in all the eyes, anterior to the macula as a flat dish-like structure measuring 7.5 ± 0.6 mm in transverse diameter, 5.2 ± 0.3 mm in longitudinal diameter, and 0.3 ± 0.5 mm in thickness. The boundary of the vitreous pocket was clear, the central portion was thin, and the peripheral portion protruded anteriorly. The posterior wall of the vitreous pocket which can be observed at the macular region was a thin layer of vitreous cortex. Mildly reflective dots were observed inside the vitreous pocket. A thin wall was observed between the vitreous pocket and the pre-papillary Cloquet's canal. On SD-OCT, the vitreous pocket of healthy young adults was visualized as a liquefied lacuna with a clear boundary measuring approximately 7.5 × 5.2 × 0.3 mm, with the posterior wall composed of a layer of vitreous cortex and separated from the pre-papillary Cloquet's canal by a thin wall.

Effect of autologous transplantation of circulating endothelial progenitor cells on oleic acid-induced acute lung injury in rabbits

Objective To investigate the effect of autologous transplantation of circulating endothelial progenitor cells (EPCs) on oleic acid-induced acute lung injury (ALI) in rabbits. Methods Thirty New Zealand long ear rabbits weighing 1.8-2.0 kg were randomly divided into 2 groups ( n = 15 each): normal saline group (group NS) and EPC group. ALI was induced by iv oleic acid 80 mg/kg. EPC (106/200 μl) or equal volume of normal saline (NS) was administered iv at 4 h after iv oleic acid injection. Arterial blood samples were obtained before (T0) and at 4, 8, 12, 24 and 48 h (T1-5) after oleic acid injection for blood gas analysis and determination of serum vascular endothelial growth factor (VEGF) concentration. The animals were then scrificed (at T5 ) and the lungs were removed for microscopic examination and determination of W/D lung weight ratio, Pulmonary infiltration of PMN and non-PMN was counted and hyaline membrane formation and hemorrhage were examined. Results PaO2/FaO2 ratio and serum VEGF concentration were significantly higher in group EPC than in group NS. Infiltration of leukocytes in the lung was significantly reduced by EPC transplantation. EPC also decreased lung water content, hyaline membrane formation and hemorrhage in the lungs. Conclusion Autologous transplantation of circulating EPC can ameliorate oleic acid-induced acute lung injury in rabbits. Key words: Stem cells; Transplantation, autologous; Respiratory distress syndrome,adult

Pharmakologische Vitreolyse

The vitreous plays an important role in the development and progression of vitreoretinal diseases. Vitrectomy is the treatment modality of choice in these cases. However, mechanical vitrectomy is incomplete. Therefore, alternative strategies have been pursued including pharmacological means such as enzymes. The goal of pharmacological vitreolysis is to make the surgical intervention easier and less traumatic. Different substances have been investigated, including chondroitinase, dispase, hyaluronidase, plasmin, and microplasmin. Besides preclinical investigations, hyaluronidase and microplasmin (ThromboGenics Ltd., Dublin, Leuven) have been tested clinically. Results from the literature are reported herein. Plasmin and microplasmin are both capable of inducing posterior vitreous detachment (PVD) in a dose- and time-dependent manner. There are no morphological or functional changes of the retina at therapeutic doses. Two phase II studies published to date demonstrate both efficacy and safety. Phase III studies are ongoing, and results are expected during 2010. Other enzymes tested show limitations in that retinal damage may occur (dispase) or liquefaction (hyaluronidase) occurs without cleavage of the vitreous cortex from the retina. Microplasmin induces PVD. Results from clinical trials show that microplasmin helps to detach the vitreous cortex from the retina. This may be advantageous in terms of complete vitreous removal and less traumatic intervention compared to mechanical techniques, such as vitrectomy and peeling of the internal limiting membrane.

Safety of the anterior vitreous detachment induced by microplasmin, pharmacologic vitreolysis to separate the posterior capsule from the anterior hyaloid

Abstract Purpose The aim of this project is to establish the safety of the use of microplasmin in the vitreolenticular interface to promote the separation of the anterior hyaloid from the posterior capsule. Methods The safety of the use of microplasmin solution will be examined in 24 eyes of 12 rabbits after having performed a cataract surgery and a primary posterior continuous curvilinear capsulorhexis and having exposed the anterior hyaloid interface with a solution of different doses of microplasmin (125µg or 250µg in 0.1ml balanced salt solution)and having left this solution in place during different time intervals starting from 5 minutes to one hour. The rabbit eyes will be examined at well‐defined time intervals: day 1 and 7, month 1,2,3,6 and 12. Slitlamp examination and OCT‐SLO imaging will be performed to monitor ocular inflammation, visual axis reproliferation and anterior vitreous anatomy. Conclusion Congenital cataracts, whether or not combined with persistent fetal vasculature may present different degrees of congenital dysgenesis of the vitreolenticular interface. Pharmacological separation of the interface between posterior lens capsule and anterior hyaloid would be benificial to improve the surgical outcome. Therefore the feasibility, safety and clinical application of intravitreal injection of microplasmin for this indication need to be examined first.

Macular Hole Secondary to Capillary Hemangioblastoma

Full-thickness macular holes affect 0.3% of the population, worldwide. This condition has a predilection for females in their sixth to seventh decade. Patients can present with severe impairment of their central vision or can be relatively asymptomatic. We believe that an optic disc hemangioblastoma adhered to the vitreous, causing an anterior displacement of the hyaloid membrane that resulted in a form of vitreomacular traction that pulled the macular hole nasally, toward the optic nerve. A 66-year-old white male presented to our clinic with decreased vision. He had a previously stable, longstanding optic disc hemangioblastoma. On presentation, an early developing full-thickness macular hole was noted. The outcome was a full-thickness macular hole that was disproportionately more detached on the nasal side of the macula. Treatment regimen included repeated intravitreal off-label injections with bevacizumab, followed by external beam radiation therapy, ultimately followed by surgery. Treatment in this case was especially complicated because of the presence of the macular hole in addition to the hemangioblastoma. The plan was to decrease vascular activity of the hemangioblastoma before proceeding with macular hole repair. First, off-label bevacizumab injections were administered, followed by external beam radiation therapy, and finally combined surgery. Surgery was successful, and to date, the macula is flat and intact.

Vitreoschisis in macular diseases

ObjectivesVitreoschisis is a possible pathogenic mechanism in macular diseases. Thus, the vitreoretinal interface was evaluated in monkey eyes and patients with various macular diseases in search of vitreoschisis. It is...

Vitrectomy for Vitreous Opacities and Macular Pucker in Gaucher Disease

To report significant surgical results in an uncommon ophthalmologic complication of a rare disease. Interventional case report. A 16-year-old girl with type III Gaucher disease experienced visual loss in both eyes. Ophthalmologic examination revealed dense whitish vitreous opacities and macular pucker OU. Visual acuity (VA) OD was 20/63 and OS was 20/25. She underwent 25-gauge vitrectomy with removal of the vitreous core, posterior vitreous cortex, and indocyanine green?stained internal limiting membrane OD. Visual acuity improved, reaching 20/25 1 year after surgery despite the appearance of small preretinal flecks. Visual acuity OS decreased some time later and vitrectomy was performed when VA OS was 20/100. Three years after surgery, BCVA was 20/25 OD and 20/20 OS 1 year after surgery. We describe a young patient with Gaucher disease with severe bilateral vitreous opacities and macular pucker. After surgery, vitreous opacities partially and progressively recurred, but the overall favorable outcome strongly supports a surgical approach in cases of this kind.

Traction on the retina induced by saccadic eye movements in the presence of posterior vitreous detachment

Posterior vitreous detachment is a fairly common condition in elderly people. Tractions exerted by the detached vitreous on the retina may result in retinal tears and detachments. We studied how these tractions can arise from saccadic eye movements. Numerical simulations have been performed on a two-dimensional model of the vitreous chamber within a rigid spherical sclera, subjected to prescribed finite-amplitude rotations about a vertical axis. The vitreous chamber was assumed to be split into two regions: one occupied by the detached vitreous, modeled as an elastic viscous solid, and the other occupied by the separated liquefied vitreous, modeled as a Newtonian fluid. At the interface between the two phases, we also considered the presence of the vitreous cortex, modeled as an elastic membrane. We tested several different configurations of the interface. In all cases, we found that eye rotations generate large tractions on the retina close to the attachment points of the membrane. Comparing them, we identified configurations of the vitreous detachment that exhibit higher tractions. We also investigated how the response to saccadic movements depends on some physical parameters, in particular on the rheological properties of the solid phase and the membrane. The numerical simulations show that the generated tractions may be of the same order of magnitude as the adhesive force between the retina and the pigment epithelium. Therefore, the model provides a sound physical justification for the hypothesis that saccadic movements, in the presence of posterior vitreous detachment, could be responsible for high tractions on the retina, which may trigger retinal tear formation.

Appearance of age-related macular degeneration in vitrectomized and nonvitrectomized eyes: an intraindividual case study

This study analyses the consequences of vitreoretinal traction on the macula and in particular the impact of a vitrectomy on the development of the age-related macular degeneration (ARMD). In this retrospective case study, 42 eyes of 21 subjects were examined. The vitreous of one eye must have been removed by vitrectomy at least 8 years ago. At that point in time, the patients had to be at least 50 years old, with a healthy vitreous body of the other eye and a healthy macula in both eyes. Both eyes were examined using an optical coherence tomography (OCT) scan, B-scan ultrasound, a binocular slit-lamp funduscopy and a fluorescence angiography (FAG) to evaluate the potential development stage of an ARMD and the vitreous status. In the follow-up examination, the patients had an average age of 73.6 years. In 0 of 21 vitrectomized eyes (0%), there were signs for an early ARMD. In 5 of 21 nonvitrectomized eyes (23.8%), we found ARMD-like changes in the angiography and slit-lamp examinations. Of these 21 eyes, five eyes presented persistent attachment of the posterior vitreous cortex to the macula, while 16 eyes showed complete posterior vitreous detachment. All five eyes (100%) with premonitory signs of an ARMD showed persistent attachment of the posterior vitreous to the macula. We demonstrated a positive relationship between a persistent attachment of the posterior vitreous cortex to the macula and early signs of ARMD. Although the precise mechanism of this relationship remains unclear, the role of chronic low-grade inflammation, chronic oxidative and mechanical stress and an increase in VEGF is discussed. Persistent vitreous attachment is likely to be another risk factor for ARMD.

Diffractive multifocal intraocular lens interferes with intraoperative view

We report an unusual finding during vitreous surgery in an eye implanted with a diffractive multifocal intraocular lens (IOL). A 70-year-old woman reported gradual visual deterioration to 20/40 in the left eye two and a half years after uneventful cataract surgery with implantation of a diffractive multifocal IOL. Funduscopic examination showed an epiretinal membrane (ERM) in the left eye. Increased macular traction was believed to cause the visual deterioration. Vitreous surgery with removal of the ERM was performed and triamcinolone acetonide (TA) was injected intravitreally to visualize the residual vitreous cortex. Although the ERM was peeled successfully, the ability to focus on the vitreoretinal interface through the IOL required great effort with decreased contrast sensitivity and ghost images of the intravitreal TA crystals. The vision improved to 20/25 4 months postoperatively. Macular surgery can be performed in an eye with a diffractive multifocal IOL; however, decreased contrast sensitivity and ghost images may interfere with the intraoperative view through the diffractive IOL in complicated cases.

Rapid, bloody, and blinding diabetic retinopathy

Rapid, bloody, and blinding diabetic retinopathy

Pathogenesis and death cause of neonatal pulmonary hemorrhage within postnatal 24h

Objective To investigate the pathogenesis and death cause of neonatal pulmonary hem orrhage (NPH) within postnatal 24 h and speculate their relation to fetal pulmonary hemorrhage. Methods To select the 114 cases of NPH within postnatal 24 h confirmed by pathological examination. According to the pathologic and clinic diagnosis materials, the pathogenesis and death cause of NPH within postnatal 24 h and their relation to fetal pulmonary hemorrhage were analyzed. Results Of the 114 cases with NPH,there were 6 cases of petechial pulmonary hemorrhage,60 cases of focal pulmonary hemorrhage and 48 cases of diffuse pulmonary hemorrhage. The discovery time of NPH were 28 cases at 0～6 h ,71 cases at 7～12 h and 15 cases at 13～24 h after birth. The pathogenesis in 114 cases of NPH could be divided into identical 2 major factors: 110 cases of the oxygen deficient factor consisting of amniotic fluid aspiration pneumonia( 62 cases) .hyaline membrane disease(24 cases) .complexity cyanotic congenital heart disease(7 cases),congenital pulmonary a-genesis(7 cases),neonatal asphyxia (7 cases),intracranial hemorrhage(2 cases) and hypoxic ischemic en-cephalopathy(1 cases) .respectively. Four cases were due to infection including sepsis which was caused by intrauterine infection. The death causes in 114 cases of NPH included hypoxia (113 cases) which consisted of pulmonary hemorrhage (74 cases) .amniotic fluid aspiration pneumonia(15 cases) .hyaline membrane dis-ease(12 cases),complexity cyanotic congenital heart disease(7 cases),congenital pulmonary agenesis(2 ca-ses) ,intracranial hemorrhage(2 cases) .neonatal asphyxia (1 cases) .and infectious factor(1 case) of sepsis which was caused by intrauterine infection. In 114 cases,82 cases had fetal distress,74 cases died from NPH directly including 3 cases with fetal distress died within a few minutes after birth. Conclusion Oxygen defi-cient is an important factor in pathogenesis and death cause of NPH within postnatal 24 h. The majority of ca-ses have the fetal distress and died from NPH directly in short time. Because of 3 cases NPH died within a few minutes after birth, therefore we conjecture that the most cases of NPH within postnatal 24 h may be a ex-tension of fetal pulmonary hemorrhage. Key words: Infant, newbom; Fetus; Pulmonary hemorrhage; Pathogenesis; Death cause