Vitreous Strands Research Articles

Cellular deposits on intraocular lenses.

We examined cellular deposits on 14 intraocular lenses (IOL) that were removed after implantation for a variety of clinical reasons. Five of the lenses were cultured to evaluate the growth potential of preexisting cells on the IOLs. The most common cells found were iris pigment epithelial cells. The thickest membranes were probably formed by iris stromal cells. Other cellular deposits included macrophages, multinucleated foreign body giant cells, lens epithelial cells, squamous epithelial ingrowth, red blood cells, uveal melanocytes, and vitreous strands. Cells around the IOL had only limited growth in tissue culture. We propose that a continuous influx of inflammatory cells in conjunction with a disruption of the blood-aqueous barrier may be an important pathogenetic mechanism for the production of thick secondary membranes around an IOL.

Nd-YAG laser in our experience.

The authors report on their experience with Microruptor 2, Fankhauser's YAG laser. Over a period of about 18 months, approximately 500 patients with different pathological conditions of the eye were treated. The treatments were noninvasive and given to outpatients under surface anesthesia. The instrument is suitable for use in cases requiring splitting of cataract residues, in capsulotomies (also in the presence of intraocular lenses), in the treatment of iridocorneal adhesions, in the prophylaxis of acute attacks of glaucoma, in ectopia pupillae, and in selected cases of vitreous membranes and strands.

Localized retinectomy indications in the treatment and prevention of retinal detachment.

Retinectomy can be helpful in several cases: retinal inversion and giant tears when the edges are rolled up, and when vitreous strands are implanted on to pieces of the tear flaps; the approach to the subretinal area (subretinal glial strands, subretinal fluid drainage, subretinal foreign bodies); nondissectable areas of retinal retraction (retinal incarceration, vitreo-retinal proliferation, etc.). Most of these retinectomies have to be supplemented by vitrectomy followed by a silicone oil injection, with peroperatory cryotherapy or argon laser photocoagulation.

Biomicroscopic Study of the Vitreous in Macular Breaks

The vitreous in 74 eyes with macular breaks was studied using the El Bayadi-Kajiura preset lens mounted on a slit lamp. Fifteen of the eyes had macular breaks secondary to various causes, and 59 eyes had idiopathic senile macular breaks. Vitreous traction, indicated by the presence of opercula or visible vitreous strands, was present in 29 (49%) of the idiopathic cases. In 17 of 31 eyes without posterior vitreous detachment (PVD), an operculum was seen. In these eyes, intravitreous traction was suspected to be the cause of macular breaks. Opercula were seen attached to the posterior hyaloid membrane in six of the nine eyes with partial PVD. An operculum corresponding to the macular break was observed on the posterior hyaloid membrane in only five of 19 eyes with complete PVD. Of the 15 eyes with macular breaks secondary to various causes, complete PVD was seen in 10 eyes, one of which had an operculum. One eye had no PVD, and four eyes had partial PVD. Opercula were detected in two of the latter eyes. In one eye of the senile group and one eye of the secondary group, partial PVD caused traction at the edges of the macular break, resulting in retinal detachment.

An Anterior Surgical Approach To Aphakic Cystoid Macular Edema

Fifteen consecutive eyes in 14 patients (six men and eight women, ranging in age from 43 to 75 years) underwent anterior vitrectomy for chronic cystoid macular edema documented by fluorescein angiography. All eyes had either vitreous adhesions to the cataract incision with pupillary distortion, or adherence of vitreous strands to the iris. Anterior vitrectomy via the corneoscleral limbus was performed in each case to remove vitreous from anterior segment structures. Thirteen of the 15 eyes showed visual improvement, with 12 of the 15 showing improvement of two Snellen lines or more. There was no direct correlation between the duration of aphakic cystoid macular edema and final visual acuity.

Direct vitreous reaction to intraocular lens implants.

Three intraocular lens implants removed during keratoplasty between 1 1/2 and 5 years after implantation revealed attachments of reactive vitreous strands and membranes contained bundles of fibers with associated small bipolar cells, pigment, and blood remnants. Some of the fibrous vitreous strands were wound around the haptics of the implants for firm anchoring. The usual reactive cell membranes on the surface of the implants were interrupted in the areas of the attachment of formed vitreous and vitreous membranes.

Surgical Therapy for Chronic Aphakic Cystoid Macular Edema

Aphakic cystoid macular edema (ACME) is a common condition seen after intracapsular cataract extractions. In an overwhelming majority of these cases, the condition improves spontaneously. Those cases that persist for months or years, however, are often associated with vitreous strands adherent to the surgical wound and distortion of the pupil. This article reviews the surgical and photocoagulation therapies for this condition that have been reported over the past two decades. All studies report encouraging results, but all have been nonrandomized, uncontrolled trials. This paper describes two randomized, controlled clinical studies that are attempting to evaluate objectively the role of vitrectomy for chronic cases of aphakic cystoid macular edema.

Vitreous management during secondary implantation

This paper describes a microsurgical system for the management of vitreous encountered during second­ ary intraocular lens implantation. Excluded from con­ sideration are those cases in which the surgeon elects to use a mechanical vitreous cutter. Also excluded are cases in which the posterior capsule is intact after an extracapsular cataract procedure. SURGICAL TECHNIQUE After topical application of a 4% solution of pilocar­ pine and local anesthesia, a wire speculum and superi­ or rectus traction suture are inserted. The microscope is positioned. A temporal or nasal conjunctival reces­ sion of 1 mm is fashioned using scissors. A 1.5-mm stab wound is made and air or sodium hyaluronate (Healon R )1. 2 is injected to maintain anterior chamber depth. The anterior chamber is inspected and the shape and size of the pupil are carefully noted. The in­ cisionis then extended to 8 mm with scissors, in a plane 1 mm posterior to the surgical limbus. If neces­ sary, the anterior chamber is again deepened using air or Healon. A Sheets lens glide 3 is introduced across the proximal iris and into the pupillary area. Pupil movement and shape are carefully observed as the lens glide is slowly advanced across the pupil towards the opposite anterior chamber angle recess. The ap­ pearance of vitreous bands is noted under magnifica­ tion. The Sheets glide acts as a probe: the tactile sen­ sation coupled with visual clues from the position, shape, and movement of the pupil are used to identify any vitreous which lies anterior to the pupil. If vitre­ ous pathology is identified, the glide is withdrawn. A microhook is used to isolate vitreous strands and these bands are then hooked and drawn to the wound where

Closed Vitrectomy and the Intraocular Implant

Closed vitrectomy was successfully performed on eyes containing intraocular lenses (IOLs) in order to remove retropseudophakic membranes, remove vitreous strands surrounding IOLs or adherent to the corneoscleral incision and iris in cases of persistent cystoid macular edema (CME), assist in the relocation of IOLs which had dislocated into the vitreous, and to relieve pseudophakic pupillary block. Closed vitrectomy was also performed to remove vitreous present in the anterior segment prior to secondary IOL implantation. Techniques and results of 33 closed vitrectomies in such instances are presented.

Candida endophthalmitis in the premature infant

An attempt was made to determine the incidence and natural history of Candida endophthalmitis in the premature infant with systemic candidiasis. Each of eight premature infants were examined by indirect ophthalmoscopy within one week of their diagnosis. At this stage, four infants had multiple fluffy white lesions on both the retina and the vitreous, together with a diffuse vitreous haze. Three of the infants had interlesional and lesional-retinal vitreous strands. Three infants treated with amphotericin B and 5-fluorocytosine showed gradual disappearance of the lesions. The fourth infant died early in the course of antifungal therapy, when the eye lesions were progressing. Candida sepsis was particularly prevalent in the very low-birth-weight infant with a prolonged hospital course and treated with multiple broad-spectrum antibiotics. The course of the eye lesions indicates a good prognosis for Candida endophthalmitis, although further follow-up is necessary.

Hemolytic ghost cell glaucoma. Further studies.

Three variations of ghost cell glaucoma that occur following cataract extraction are presented. The most common variant occurred when a large, anterior chamber and vitreous hemorrhage complicated the immediate postoperative course. Weeks later, as the anterior chamber hemorrhage cleared, ghost cells that had formed within the vitreous cavity passed forward into the anterior chamber and obstructed the aqueous outflow channels. Ultramicroscopy of aqueous specimens confirmed that RBC ghost were the major aqueous component and were therefore the cause of the glaucoma, distinguishing this glaucoma from glaucoma due to macrophages and RBC debris. Scanning and transmission electron microscopy of hemorrhagic vitreous showed that RBCs disintegrated into ghosts and denatured extracellular hemoglobin aggregates. The latter, common in the vitreous, were bound within vitreous strands, accounting for their absence in the anterior chambers of patients with ghost cell glaucoma. In correlation with clinical findings, perfusion studies showed that neither fresh RBCs nor ghosts could pass through an intact anterior hyaloid face.

Gitterfiguren bzw. dendritische Streifen der Netzhautperipherie

Latticed or dendritic lines (true white lines) on the periphery of the retina. Vitreo-retinal adherences between the ora and equator correspond to former embryonal blood vessels to the vitreous (or retinal vessels) attaching to the retina. Between attachments of vitreous consolidations coming from in front and behind as a congenital anomaly of the retina, the latter is either loosened or replaced by connective tissue, or there is a defect, wedge-shaped from within outwards (colobomatous). These are obviously very frequently comgenital. The vitreous between and above the vitreous-retinal attachments is always liquefied and structureless. With increasing age, there is a reactive proliferation of the connective tissue (vessel-vitreous medullary cells) and pigmented epithelium. This new tissue either replaces the retina or rests on it distinctly localized, and has a strong tendency to hyalinization and sclerosis (sclerotic degenerative area). The latticed or dendritic lines (true white lines) on the periphery of the retina which for preference appear in the region of the degenerative sclerotic area sometimes consist of obliterated vessels with hyalinized walls and sometimes of hyaline connective tissue threads which are independent of the vessels. Frequently the vitreous fibre strands (vitreo-retinal adherences) may also continue through the inner retinal layers as far as these dendritic hyaline (white) retinal threads of connective tissue.

Experimental Fibroplasia in the rabbit vitreous. Retinal detachment induced by autologous fibroblasts.

Fibroblasts were cultured from autologous dermal connective tissue of albino rabbits and implanted (1 X 10(6)-3 X 10(6) cells) into the vitreous space of 18 rabbit eyes under sterile surgical conditions. In 13 eyes a distinct growth of the cells occurred, and vitreous strands were formed. In 9 eyes a retinal detachment followed, and in some it was associated with traction of optic nerve tissue into the vitreous. The proliferating fibroblasts produced collagen fibrils showing a band period of 45-55 nm. Intravitreal collagen formation is considered to be a pathologic phenomenon capable of inducing the development of vitreous retraction and retinal detachment.

Bacterial Endophthalmitis Following Suture Removal after Penetrating Keratoplasty

Of three cases of bacterial endophthalmitis occurring after removal of corneal sutures following penetrating keratoplasty, two were associated with wound dehiscence and one was not. Factors that may predispose to wound dehiscence and subsequent infection are: use of fine suture material, corticosteroids, and chronic topical antibiotics; early removal of corneal sutures; lack of adherence to strict asepsis prior to and after suture removal; and open suture tracts that may be kept open by incarceration of vitreous strands. Late corneal wound dehiscence may occur with subsequent development of endophthalmitis as long as three days after suture removal. The use of topical antibiotics before and after suture removal may decrease the potential for infection. In addition, early recognition of intraocular infection by the patient and the surgeon for immediate institution of antimicrobial and anti-inflammatory therapy may preserve useful vision.

A new concept for vitreous surgery. 7. Two instrument techniques in pars plana vitrectomy.

During vitrectomy through the pars plana, a second instrument, introduced through the opposite pars plana, is useful for specific surgical situations. Removal of pooled blood is facilitated by insertion of a 22-gauge needle connected to an additional infusion bottle. Large bleeding vessels are diathermized with a straight diathermy needle. Preretinal membranes are peeled off with a modified 22-gauge hypodermic needle. Solid vitreous strands are cut with a vitreous scissors, and foreign bodies are removed with a foreign-body forceps. Fiberoptics provide optimal illumination inside the eye for these manipulations.

Extracellular fibril formation by neuroglial cells at the vitreoretinal junction of the human eye.

Extracellular fibril formation was observed within the interruptions of the basement membrane at the retinal surface of pathologically altered and senile human eyes. The fibril bundles apparently are the ultramicroscopic equivalence of the preretinal vitreous condensations and vitreous traction strands, visible biomicroscopically with the contact lens. The fibrils are assumed to be produced by the Muller cells, as an attempt to reform the damaged basement membrane, and in this way to restitute a new borderline between the neuroectodermal retinal tissue and the mesenchymal vitreous body.

Experimental vitrectomy. Instrumentation and surgical technique.

A recently developed instrument (vitrophage) has been proven effective in removal and replacement of vitreous and in the cutting of vitreous strands in experimental vitreous hemorrhage. The instrument is inserted at the pars plana under direct observation of the fundus through a three-mirror lens and operating microscope, and it can be manipulated easily inside the eye by a specially-designed manipulator. The technique and preliminary results of this experimental study are reported.

Experimental transscleral freezing at temperatures ranging from -20 to -160 degrees C.

The ophthalmoscopic and histologic aspects of cryocoagulation in 264 rabbit eyes were studied. Temperatures ranged from -20° to -160° C, times of freezing varied from 5 to 60 seconds. The periods of observation ranges from 30 minutes to 3 months after cold treatment. 1. Scleral thinning or scarring was not observed and there were no signs of overdosage: scleral lesions (except pigment migration) disappeared within two to four weeks after cold application. The condition of the sciera two weeks after intense cryocoagulation was invariably good enough to permit reoperation. 2. Choroidal lesions were reversible irrespective of temperature and time of freezing, with the exception of pigmentary changes and atrophy of the choriocapillaris. At -100°, -130° and -160° hyperaemia, haemorrhages and plasmatic exudation in the choroid were more intense than at higher temperatures. At -130° and-160° the vessel walls were damaged to such an extent that many choroidal and subretinal haemorrhages developed immediately after freezing. 3. After freezing at -40° and lower temperatures an irreversible atrophy of all the retinal layers developed. At -60°, and in particular at -100° and lower temperatures, retinal haemorrhages and oedema occasionally developed, which were sometimes so intense as to cause a rupture of the internal limiting membrane. 4. The early subretinal oedema located in the area of freezing developed most rapidly and was most intense after freezing at -100°; it caused numerous retainl tears in the treated area during the first few hours after cold application but was rapidly resorbed in the course of one day. At -130° development and resorption of the oedema occurred more slowly; it was still present in the stage of incipient chorioretinal adhesion. At -160° the late subretinal oedema developed one week after freezing, leading to retinal tears around the area of coagulation where a good chorioretinal adhesion had already been attained. The above mentioned complications interfered with a good chorioretinal adhesion. 5. Cold-induced lesions of the vitreous developed only at temperatures of -130° and -160°. Small vitreous haemorrhages were resorbed and vitreous clouding which was also ophthalmoscopically visible frequently cleared. Vitreous strands would sometimes interfere with good chorioretinal adhesion. 6. The intensity of the lesions induced by the Linde cryode is influenced by various factors :

The detection of focal vitreous prolapse.

DURING cataract wound closure, the surgeon should have some method of being reasonably certain that no vitreous strands are trapped in the wound. The presence of characteristic iris distortion, more notable with round pupil surgery, is distinctive of vitreous incarceration in many instances; but the incarceration of a slender or tenuous vitreous strand (Fig 1) may not result in iris distortion until hours or days after wound closure. Such thin or tenuous strands of incarcerated vitreous will often persist, without iris distortion, after an obvious vitreous prolapse has been thought to be completely reposited or removed; and even a tiny incarceration may lead to any of the possible complications. A technique which I have found to be nearly always successful in detecting such focal, or meridional, or very tiny areas of vitreous incarceration consists of placing a moistened cotton-tipped applicator at the lips of the wound (Fig 2,<i>top</i>) and

Comparison of scleral resection and scleral folding in experimental shortening of the eye.

SHORTENING of the eyeball by scleral resection has proved to be successful in many cases of retinal detachment in which diathermy either has failed or offers a poor prognosis. Such cases include detachments in aphakic eyes without visible tears, total detachments, cases with exceptionally large tears, and detachments with fixed star folds or vitreous strands. Muller* was the first to perform the scleral resection operation for retinal detachment in 1903, but Lindner † deserves the credit of reviving and advocating the idea of Muller in 1933. He elaborated a new, precise technique and defined the cases in which success could be expected. Since then many authors have reported results achieved by this operation, among them Pischel and Miller, 7 Pischel, 8 Bogart, 9 Vail 10 Borley, 11 and Hughes. 12 Because certain hazards and complications are encountered in scleral resection, Lindner suggested in 1933 3 a method of scleral folding to