Iridocorneal Endothelial Syndrome Research Articles

Confocal microscopy in the iridocorneal endothelial syndrome

AIMSTo report the appearances of iridocorneal endothelial (ICE) syndrome from real time, white light confocal microscopy.METHODSThree consecutive patients, each with ICE syndrome, were examined prospectively. Corneal specular and confocal microscopic...

Long-term outcome of aqueous shunt surgery in ten patients with iridocorneal endothelial syndrome

Purpose To report the long-term outcome of ten patients with iridocorneal endothelial (ICE) syndrome who underwent aqueous shunt surgery for uncontrolled glaucoma. Design Noncomparative, retrospective case series. Participants The authors reviewed charts of ten patients with ICE syndrome-related glaucoma who underwent aqueous shunt surgery at one institution between 1987 and 1996. Main outcome measures Intraocular pressure (IOP), number of glaucoma medications, and further surgical interventions were measured. Results With a median follow-up of 55 months, four eyes had adequate IOP control (IOP < 21 mmHg) with one or two medications after the initial aqueous shunt surgery. An additional three eyes achieved adequate IOP control after one or more tube repositionings or revisions of the initial aqueous shunt. In this series, the aqueous shunt surgery most often failed because of blocking of the tube ostium by iris, ICE membrane, or membrane-induced tube migration. Conclusion Aqueous shunt surgery appears to be an effective method for IOP lowering in some eyes with ICE syndrome-related glaucoma when medical treatment or conventional filtration surgeries fail, but additional glaucoma procedures and/or aqueous shunt revisions and tube repositionings are not uncommon.

Glaucoma drainage devices: pros and cons.

Glaucoma drainage devices are an option in the management of complicated glaucomas that carry a high risk of failure from conventional filtering surgery. Examples include the glaucomas associated with aphakia or pseudophakia, neovascular glaucoma, and glaucomas associated with trauma, uveitis, epithelial downgrowth, iridocorneal endothelial syndrome, vitreoretinal disorders, and penetrating keratoplasty. Modifications in the various implant designs have been developed to limit the occurrence of postsurgical complications such as hypotony, serous and hemorrhagic choroidal detachment, tube and plate avulsion, tube exposure, and corneal endothelial damage.

Ring melanoma—a rare cause of refractory glaucoma

BACKGROUND Ring melanoma of the ciliary body and iris is extremely rare and often has adverse histology. This tumour may cause raised intraocular pressure. METHODS A review of four cases...

Structure, development and function of cytoskeletal elements in non-neuronal cells of the human eye.

The cytoskeleton, of which the main components in the human eye are actin microfilaments, intermediate filaments and microtubules with their associated proteins, is essential for the normal growth, maturation, differentiation, integrity and function of its cells. These components interact with intra- and extracellular environment and each other, and their profile frequently changes during development, according to physiologic demands, and in various diseases. The ocular cytoskeleton is unique in many ways. A special pair of cytokeratins, CK 3 and 12, has apparently evolved only for the purposes of the corneal epithelium. However, other cytokeratins such as CK 4, 5, 14, and 19 are also important for the normal ocular surface epithelia, and other types may be acquired in keratinizing diseases. The intraocular tissues, which have a relatively simple cytoskeleton consisting mainly of vimentin and simple epithelial CK 8 and 18, differ in many details from extraocular ones. The iris and lens epithelium characteristically lack cytokeratins in adults, and the intraocular muscles all have a cytoskeletal profile of their own. The dilator of the iris contains vimentin, desmin and cytokeratins, being an example of triple intermediate filament expression, but the ciliary muscle lacks cytokeratin and the sphincter of the iris is devoid even of vimentin. Conversion from extraocular-type cytoskeletal profile occurs during fetal life. It seems that posttranslational modification of cytokeratins in the eye may also differ from that of extraocular tissues. So far, it has not been possible to reconcile the cytoskeletal profile of intraocular tissues with their specific functional demands, but many theories have been put forward. Systematic search for cytoskeletal elements has also revealed novel cell populations in the human eye. These include transitional cells of the cornea that may represent stem cells on migration, myofibroblasts of the scleral spur and juxtacanalicular tissue that may modulate aqueous outflow, and subepithelial matrix cells of the ciliary body and myofibroblasts of the choroid that may both participate in accommodation. In contrast to the structure and development of the ocular cytoskeleton, changes that take place in ocular disease have not been analysed systematically. Nevertheless, potentially meaningful changes have already been observed in corneal dystrophies (Meesmann's dystrophy, posterior polymorphous dystrophy and iridocorneal endothelial syndrome), degenerations (pterygium) and inflammatory diseases (Pseudomonas keratitis), in opacification of the lens (anterior subcapsular and secondary cataract), in diseases characterized by proliferation of the retinal pigment epithelium (macular degeneration and proliferative vitreoretinopathy), and in intraocular tumours (uveal melanoma). In particular, upregulation of alpha-smooth muscle actin seems to be a relatively general response typical of spreading and migrating corneal stromal and lens epithelial cells, trabecular cells and retinal pigment epithelial cells.

Endothelial metaplasia in the iridocorneal endothelial syndrome

Endothelial metaplasia in the iridocorneal endothelial syndrome

Treatment of glaucoma secondary to ICE syndrome

Iridocorneal Endothelial (ICE) Syndrome refers to a group of three similar entities consisting of a combination of abnormalities to the corneal endothelium and iris. Approximately 50% of all patients who present with an ICE syndrome will later develop secondary angle closure glaucoma which is often refractory to conventional therapy. The following case report presents a patient with essential iris atrophy and secondary angle closure glaucoma. The clinical features of the disease, mechanisms of secondary glaucoma, and management strategies will be discussed.

The contralateral corneal endothelium in the iridocorneal endothelial syndrome.

To evaluate the corneal endothelial morphometric measures of the contralateral, clinically uninvolved eye of patients with the iridocorneal endothelial (ICE) syndrome. A retrospective review of the specular microscopic photographs of the contralateral corneal endothelium of all patients with ICE syndrome seen at Mayo Clinic, Rochester, Minn. Ophthalmology department, Mayo Clinic. Twenty-eight patients with unilateral ICE syndrome who had bilateral endothelial photographs (ICE group) and 28 normal, age-matched control subjects (control group). Percentage of hexagonal cells, coefficient of variation of cell area, and endothelial cell density. For each patient and control, 100 endothelial cells were digitized from projected endothelial photomicrographs of the central corneas in the uninvolved eyes. A statistically significant decrease was noted in the mean percentage of hexagonal cells (ICE, 62%; control, 69%; P = .002), and an increase was noted in the mean coefficient of variation of cell area (ICE, 0.28; control, 0.25; P = .02) in the patients with ICE syndrome compared with normal, age-matched controls. The mean endothelial cell density did not differ significantly between the 2 groups (ICE, 2588; control, 2759; P = .10). Our data suggest that the clinically uninvolved, contralateral eyes in patients with ICE syndrome have subclinical endothelial abnormalities as evidenced by a relatively low percentage of hexagonal cells and a relatively high coefficient of variation of cell area.

Pathology of the iridocorneal-endothelial syndrome. The ICE-cell.

Pathology of the iridocorneal-endothelial syndrome. The ICE-cell.

Bilateral Iridocorneal Endothelial Syndrome Presented as Cogan-Reese and Chandler??s Syndrome

Iridocorneal endothelial (ICE) syndrome includes Chandler's syndrome, essential iris atrophy, and the Cogan Reese syndrome. The purpose of this article is to describe a rare case with two forms of the syndrome simultaneously. A case of Cogan Reese syndrome in one eye and Chandler's syndrome in the fellow eye is reported. During 5 years of follow-up only slight progression, manifested in episodes of blurred vision, occurred because of corneal changes. Glaucoma did not develop. ICE syndrome is considered as unilateral, although cases of bilateral involvement of the same variant have been described. But a simultaneous presentation of two different forms might occur, as in this patient.

The Histopathology of the Iridocorneal-Endothelial Syndrome

The iridocorneal-endothelial (ICE) syndrome is characterised clinically by a "hammered-silver" appearance of the corneal endothelium, corneal failure, glaucoma, and iris destruction. Specular photomicroscopic studies of the corneal endothelium have demonstrated a population of abnormal cells termed "ICE cells." The purpose of this study was to define the histological appearances typical of this disease and in particular the ultrastructural morphology of the ICE cell. Thirty-five corneas, 11 trabeculectomy specimens, and 3 failed corneal grafts taken from patients with the ICE syndrome were examined by transmission and scanning electron microscopy. Comparison was made with seven normal corneas. Ten corneas and two trabeculectomy specimens demonstrated a population of well-differentiated cells with epithelial features such as desmosomes, tonofilaments, and microvilli. Other cell types identified were cells that resembled those of normal corneal endothelium, inflammatory cells, and cells with a fibroblast-like morphology. It seems likely that the epithelial cells of our specimens are the histological equivalent of the ICE cell seen by specular photomicroscopy. The other cell types may be either residual normal endothelial cells or else arise from secondary phenomena of various kinds.

The composition of wide-spaced collagen in normal and diseased Descemet's membrane.

Descemet's membrane, the specialised basement membrane of the corneal endothelium, contains a form of extracellular matrix described as wide-spaced collagen. In healthy human Descemet's membrane, wide-spaced collagen forms a highly ordered array in a region called the anterior banded zone. However, in corneal endotheliopathies such as Fuchs' endothelial dystrophy and the iridocorneal-endothelial syndrome large amounts of wide-spaced collagen are deposited posterior to Descemet's membrane in a grotesque parody of the anterior banded zone termed a posterior collagenous layer. The purpose of this study was to identify the composition of the wide-spaced collagen found in the Descemet's membrane of normal and diseased human corneas. Tissue from three normal human corneas, three from patients with Fuchs' endothelial dystrophy and five from patients with the iridocorneal-endothelial syndrome was prepared for immuno-electron microscopy by freezing or embedding in Lowicryl K4M resin. Immunocytochemistry on ultrathin sections was performed with antibodies to collagen Types I, III, V, VI and VIII, fibronectin, laminin, P component and tenascin. Ultrastructural labelling of the wide-spaced collagen in the anterior banded zone of normal and diseased corneas and also of the wide-spaced collagen in the posterior collagenous layer of all the diseased corneas was demonstrated with antibody to collagen Type VIII. Wide-spaced collagen was not labelled by any of the other antibodies used. Large amounts of Type VIII collagen are present in discrete regions of healthy and diseased Descemet's membrane. The deposition of Type VIII collagen may significantly influence the pathobiology of the corneal endotheliopathies.

Herpes Simplex Virus in Iridocorneal Endothelial Syndrome-Reply

In reply Drs Hooks and Kupfer suggest that because HSV DNA is found in the corneas of normal persons and of those with chronic nonviral diseases, its presence in ICE specimens is not unexpected. They claim that to establish an etiologic relationship, combined serologic and HSV DNA tests of patients with the ICE syndrome are mandatory. Until then, antiviral treatment proposals are premature. We use the same articles 1,2 cited by Drs Hooks and Kupfer to make the following points: (1) the premise that HSV DNA is commonly found in corneal tissues is not supported by that literature; (2) the localization of HSV DNA intraocularly, together with its prevalence in corneas of patients with the ICE syndrome, is significant and supports a role for HSV in the ICE syndrome; and (3) serologic tests do not provide information additional to that yielded by HSV DNA assays in establishing an etiologic relationship.

Descemet's membrane in the iridocorneal-endothelial syndrome: Morphology and composition

The iridocorneal-endothelial syndrome is a disease of the ocular anterior segment characterized by corneal failure, glaucoma and iris destruction. Specular photomicroscopical and histological studies suggest the disorder is caused by a population of abnormal corneal endothelial cells. In other corneal endotheliopathies Descemet's membrane, the basement membrane underlying the endothelial cells, is disfigured by the presence of an abnormal region of extracellular matrix termed a posterior collagenous layer, which is laid down by the diseased endothelial cells. In this study we sought to establish the typical morphology and composition of Descemet's membrane in the iridocorneal-endothelial syndrome. Ultrastructural examination of Descemet's membrane in 27 keratoplasty specimens identified three morphologic patterns. In the majority there was a posterior collagenous layer which in all cases consisted of an anterior layer of wide-spaced collagen and a posterior layer of microfibrils embedded in an amorphous matrix. In four specimens which did not possess a posterior collagenous layer the anterior banded zone of Descemet's membrane was absent. In five corneas Descemet's membrane was normal. The composition of the posterior collagenous layer was examined by immunoelectron microscopy (five corneas) and histochemistry (six corneas). Collagen Types I, III, V, VI and VIII, fibronectin, tenascin and oxytalan were microfibrillar components, collagen Type VIII formed wide-spaced collagen whilst laminin was present in the amorphous matrix. The stereotyped derangements of structure and composition identified in the endothelial basement membrane may significantly influence the pathobiology of this disorder.

Erratum: On the pathology of the iridocorneal-endothelial syndrome: The ultra-structural appearances of ‘subtotal-ICE’

In the Discussion section of this paper the first sentence of the third paragraph (p. 22, right-hand column, line 5) should read: Normal endothelial cells were often damaged or necrotic at the boundary zone, suggesting that ICE-cells may have a toxic effect on neighbouring normal endothelial cells.

On the pathology of the iridocorneal-endothelial syndrome: the ultrastructural appearances of 'subtotal-ice'.

The iridocorneal-endothelial syndrome (ICE syndrome) is characterised by corneal failure, glaucoma and iris destruction. Specular photomicroscopical and histological studies of the corneal endothelium in this disease show a population of abnormal cells named 'ICE-cells'. In many patients some areas of the endothelium are occupied by ICE-cells and others by normal cells, an appearance described as 'subtotal-ICE'. Specular photomicroscopical observations suggest that ICE-cells and normal endothelial cells may actively interact at the boundary zone where they meet. The purpose of this study was to examine the ultrastructural appearances of the boundary zone to gain insight into the cellular pathology of this region. Thirty-five corneas taken from patients with the ICE syndrome were examined by light, transmission and scanning electron microscopy. The subtotal-ICE appearance was demonstrated in four specimens. The morphology of ICE-cells at the boundary zone suggests that they are non-motile but also implies a general state of high metabolic activity. Many of the normal endothelial cells in this region are damaged, an appearance which may result from a toxic effect from the nearby ICE-cells.

Corneal endothelial cell abnormalities in an early stage of the iridocorneal endothelial syndrome.

A corneal disc, obtained from a 52-year-old woman suffering from an early stage of the iridocorneal endothelial syndrome (ICE), was investigated by various morphological techniques to analyse the structural variations in the endothelial cells and to identify the collagen types within the abnormal layer of Descemet's membrane. Scanning electron microscopy of the posterior corneal surface revealed a mosaic of (a) flat hexagonal cells resembling irregular but normal endothelial cells, and (b) rounded hexagonal (ICE) cells with numerous surface microvilli. Degenerative changes were present in each cell type, but were more common in the flat hexagonal cells which contained intracytoplasmic spaces. By transmission electron microscopy the flat hexagonal cells exhibited many of the features of normal endothelial cells in terms of organelles and intercellular attachments, but lateral invaginations were absent. The ICE cells differed in that the apical surface was covered by microvilli and the cytoplasm contained tonofilaments, which were also observed by light microscopic immunocytochemical staining. Most commonly, intercellular attachments were rudimentary in both types of cell and intercellular spaces were dilated, but desmosomes were sometimes prominent in the ICE cells where interdigitations were pronounced. In some sectors, the basal surface of the ICE cells was indented by deposition of clumps of fibrillar collagenous material. An immunocytochemical study of the abnormal posterior deposits localised type IV collagen to the amorphous matrix and collagen types III and V, but not type I, to the collagen fibril bundles. Mononuclear inflammatory cells were identified between the ICE cells in the monolayer. The evidence suggests that some of the flat hexagonal cells were undergoing a degenerative change while others were transforming into ICE cells.

Surgical Results of Penetrating Keratoplasty in Essential Iris Atrophy

Results of penetrating keratoplasty in iridocorneal endothelial syndrome have been considered favorable based on past studies; however, documented results in eyes specifically with essential iris atrophy are lacking. A retrospective study was performed to evaluate all patients at the University of Pittsburgh with essential iris atrophy who had undergone penetrating keratoplasty for corneal decompensation over 21 years (1971-1992). Penetrating keratoplasty had been performed on six eyes with essential iris atrophy for corneal decompensation. All eyes postoperatively had evidence of persistent anterior uveitis resistant to corticosteroid treatment with one or more episodes of graft reaction. Five of the six eyes (83.3%) ultimately went on to graft failure. Two of the six eyes (33.3%) rejected grafts on two separate occasions. Penetrating keratoplasty in essential iris atrophy was frequently associated with chronic anterior uveitis and immunologic graft failure.

Glaucoma drainage implants.

Glaucoma drainage implants provide a useful option in the management of complicated glaucomas for which the risk of failure of conventional filtering surgery is high. The basic design of these devices is similar; a silicone tube shunts aqueous humor from the anterior chamber to a fibrous capsule surrounding a synthetic plate or band positioned at the equatorial region of the globe. The capsule serves as a reservoir for aqueous drainage. Drainage implants have been used in the treatment of various refractory glaucomas, including those associated with aphakia and pseudophakia, prior unsuccessful filtering surgery, anterior segment neovascularization, trauma, youth, uveitis, epithelial downgrowth, iridocorneal endothelial syndrome, vitreoretinal disorders, and penetrating keratoplasty. Modifications in implant design and surgical technique have been developed to limit the occurrence of postoperative complications such as hypotony and its related sequelae, and strabismus.

An audit of disease diagnoses made by optometrists

Background: Several Australian ophthalmologists have sworn affidavits that, in their opinion, optometrists have deficient training in the detection of eye disease and systemic disease having ocular manifestations, and are unable to detect a number of medical conditions having ocular manifestations. The deponents swore that optometrists could not make a medical diagnosis because they lack medical Hampton, Victoria training. To test these opinions this report details a prospective comparison of diagnoses made by three optometrists with the diagnosis subsequently made by the ophthalmologist or physician to whom the patients were referred. Methods: All referrals made to ophthalmologists or physicians were recorded, together with the optometrists' diagnoses, which were recorded prior to referral. On receipt of the medical practitioner's report, his or her diagnosis was recorded and compared with the optometrist's diagnosis. Results: Four patients referred to ophthalmologists were lost to follow‐up. Agreement between the optometrist's and ophthalmologist's diagnoses was unequivocally correct in 114 (93.4 per cent) of the 122 referrals for which follow‐up was available. The optometric diagnoses of ophthalmic disease were correct, but incomplete, in six cases and, in two cases (Saltzman's dystrophy and Chandler's syndrome), the optometrist's diagnosis was inappropriate. Referrals to family physicians totalled 18, of which three were lost to follow‐up. Of the remaining 15 patients referred, 12 diagnoses (70 per cent) were correct and three were incorrect. The three incorrect diagnoses were one case of suspected cranial arteritis and two cases of suspected diabetes, or impaired glucose tolerance. There were 38 separate diagnostic conditions referred to ophthalmologists and 11 separate conditions referred to general physicians. Conclusions: The optometrists who conducted this study were able to make diagnoses over a wide range of ocular and systemic diseases. These diagnoses were substantially in agreement with the diagnoses made by ophthalmologists and general physicians. This suggests that die training and clinical experience of optometrists can be adequate to provide a high standard of primary eye care and that optometrists are able to detect disease conditions that require referral to medical practitioners.