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PubMed1986

Lack of association between iris color and primary iris cysts.

A case-control study of 78 white patients with primary cysts of the iris was undertaken. Two control groups were established for comparison with the subjects. Contingency tables were used to evaluate the distribution of iris color among subjects and controls. Statistical testing (chi 2) indicated no significant association of iris color with the presence of a primary iris cyst (P greater than .05). These results indicated that primary iris cysts do not exhibit the association with light iris color previously documented for iris melanocytic lesions.

Adolescent↗
PubMed1985

Substance P-containing sensory nerves in the rat iris. Normal distribution, ontogeny and innervation of intraocular iris grafts.

Trigeminal, substance P-containing nerves have been studied in the stretch-prepared rat iris with immunohistochemical techniques. The normal iris exhibited a slightly irregular plexus of individual fibres in the dilator, intermingled with thin, meandering axon bundles. The sphincter contained more circumferentially oriented fibres. Occasional free nerve endings were present in all parts of the iris; no obvious association with blood vessels was detected. All substance P-positive nerves in the iris disappeared after lesioning the trigeminal nerve. Irides of neonates showed scattered, smooth fibres in a sparse plexus, without visible axon bundles. Over the first two postnatal weeks, the density of innervation developed rapidly, reaching a transiently supranormal level and fluorescence intensity, compared to adulthood. From 3 weeks on, the pattern and density of substance P-containing fibres approached the normal adult appearance. In irides grafted to the anterior eye chamber, the intrinsic substance P nerves degenerated, disappearing completely after 5 days. Reinnervation from the host irides transpired over the next few weeks, approximating normal density after 3 weeks, and organotypic density and distribution from 4 weeks on. No obvious hyperinnervation was encountered after longer postoperative times (3 months). In the host iris, many substance P fibres disappear or exhibit low fluorescence intensity during the first postoperative week, recovering fully during the next 2 weeks. Over longer postoperative periods irregular, moderate hyperinnervation developed with increased numbers of axons in bundles. In conclusion, we show normal distribution and plasticity during ontogeny and maturity of substance P-containing iris nerves in the rat, with a sensitive immunohistochemical technique in iris whole mounts.

Animals↗
PubMed1978

Fluorescein angiography of the iris. A correlation of microangiopathy in the iris and retina.

Fluorescein angiography of the iris using filters that eliminated pseudofluorescence was performed. In 10 of 40 non-diabetic healthy eyes, a fine-grained leakage of dye occurred from capillaries of the pupillary margin (PML). In 87 of 94 diabetic eyes with or without retinopathy a PML was present. The vascular changes of the iris were compared with those of the retina as disclosed by fundus fluorescein angiography. In 14 of 18 eyes without retinopathy PML was observed. In 25 of 28 eyes with non-proliferative retinopathy there was a PML, 12 of those in addition showed extravasation to the iris stroma. All 48 eyes with proliferative retinopathy showed PML. In addition, 19 of these had extravasation to the iris stroma and 26 iris neovascularization. When iris neovascularization is present, larger fibrovascular proliferations are usually found in the vitreous space, often associated with recurrent vitreous haemorrhages or retinal detachment. Iris angiography yields valuable information on the vitreo-retinal diabetic sequelae and is useful for selection of such eyes for vitrectomy.

Adult↗
PubMedDate not supplied

Iris claw lens: anterior and posterior iris surface fixation in the absence of capsular support during penetrating keratoplasty.

BACKGROUND: Intraocular lens implantation in eyes with pseudophakic or aphakic corneal edema and insufficient posterior capsular support presents a surgical challenge. The iris claw lens has the advantage that it can be fixated to the iris without sutures because the peripheral iris is incarcerated between the claws. METHODS: We present the results of a study with implantation of an iris claw lens in combination with penetrating keratoplasty in 19 eyes of 19 patients with pseudophakic or aphakic corneal edema which lacked posterior capsular support. The lens was fixated on the anterior iris surface (12 eyes) or posterior iris surface (seven eyes). RESULTS: Mean follow-up time was 11.8 months (7 to 21 months). All grafts remained clear. One patient was lost for follow up after 3 months. Visual acuity improved in 83% of the patients. Twenty-eight percent of the patients had a visual acuity of > or = 20/40. Complications such as pigment dispersion, glaucoma, peripheral synechiae, and lens decentration were rare. CONCLUSIONS: We feel iris claw lens implantation combined with penetrating keratoplasty is a safe alternative to achieve pseudophakia in eyes with corneal edema and inadequate posterior capsular support.

Adult↗
PubMed2006

High prevalence of plateau iris configuration in family members of patients with plateau iris syndrome.

PURPOSE: The purpose of the study was to ascertain the prevalence of plateau iris syndrome in the first-degree relatives of those patients affected with plateau iris syndrome. METHODS: All patients seen with plateau iris syndrome over a 5-year period were identified. These patients were approached for participation and first-degree family members above 18 years of age were screened. All people identified with plateau iris configuration underwent ultrasound biomicroscopy to document and confirm the angle configuration and subsequent gonioscopy after laser iridotomies. RESULTS: Sixteen patients were identified; 3 refused to participate, 2 were unable to be contacted, and 1 withdrew after initially consenting to participate. In this case, the patient agreed to participate, but all her living first-degree family members refused to be screened. Among the 10 patients whose living first-degree relatives were screened, we found 5 families with at least 1 additional first-degree family member having plateau iris syndrome. CONCLUSIONS: Some families have more than 1 member with plateau iris syndrome. The pattern of inheritance resembles an autosomal dominant pattern with incomplete penetrance.

Adult↗
PubMed1989

Different muscarine receptors mediate the prejunctional inhibition of [3H]-noradrenaline release in rat or guinea-pig iris and the contraction of the rabbit iris sphincter muscle.

To investigate the muscarine receptor type mediating inhibition of [3H]-noradrenaline release from the isolated rat and guinea-pig iris we have determined the potency of antimuscarinic drugs to antagonize the methacholine-induced inhibition of [3H]-noradrenaline overflow evoked by field stimulation (3 Hz, 2 min). The prejunctional apparent affinities were compared with those obtained for postjunctional muscarine receptors mediating the methacholine-induced contraction of the isolated rabbit iris sphincter muscle. Prejunctional apparent affinity constants of pirenzepine (6.67), himbacine (8.51), methoctramine (7.92), 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP, 8.00), hexahydro-difenidol enantiomers (6.92, (R); 5.77, (S)) in the rat iris and methoctramine (7.58) in the guinea-pig iris indicate the presence of M2 receptors. Although the postjunctional affinity constants in the rabbit iris sphincter of methoctramine (5.93), gallamine (3.92), and 4-DAMP (9.07) confirm our previous suggestions of the presence of M3-like receptors, the results obtained with the hexahydro-difenidol enantiomers do not agree with that concept. The postjunctional affinity constants of the hexahydro-difenidol enantiomers were not different from the prejunctional values (6.86, (R); 5.55, (S)), indicating a similar and low degree of stereoselectivity for these stereoisomers at both receptor sites (14 and 17, (R)/(S)-ratios, respectively). Hence, the postjunctional muscarine receptor in the rabbit iris sphincter fails to exhibit the high degree of stereoselectivity observed for hexahydro-difenidol enantiomers at M3 receptors on other smooth muscles.

Animals↗
PubMed1985

Immature and mature neurofilament-immunoreactive trigeminal fibers can innervate the iris as studied by intraocular grafting of iris and trigeminal ganglia.

Using immunohistochemistry on stretch-prepared whole mounts of adult rat irides, a dense, well-organized plexus of neurofilament-positive nerves originating in the trigeminal ganglion can be visualized. Such a two-dimensional tissue preparation is well-suited for studies on sensory and autonomic nerve fiber growth. In the present study the growth capacity of such neurofilament-positive nerves has been studied immunohistochemically. In irides homologously transplanted to the anterior eye chamber of adult albino rats, the intrinsic neurofilament-positive network had almost completely disappeared 4 days postoperatively. In whole mounts of iris grafts after 15 days and 4 weeks in oculo a gradually increasing plexus of nerves was observed. After 3.5 months in oculo a dense, regular network of fluorescent fibers had formed in the iris grafts to the same magnitude as in situ. However, whereas large axon bundles constituted a prominent feature of the distribution of neurofilament-positive nerves in situ, only a few and relatively thin axon bundles were seen in the grafts. The growth capacity of the neurofilament-positive trigeminal nerves was also studied by grafting fetal trigeminal ganglia to the anterior eye chamber. As visualized in cryostat sections, trigeminal grafts contained a large number of strongly fluorescent perikarya and a high density of positive fibers after intraocular maturation. Such grafts readily innervated the host iris. In the area immediately adjacent to the grafts, thin, parallel, rather weakly fluorescent fibers radiated out from the ganglia. When mature trigeminal grafts with attached host iris were regrafted to the anterior eye chamber of adult animals for a few days, in order to remove the intrinsic host iris innervation, such irides showed outgrowing fibers, often organized in small axon bundles, at long distances from the ganglion graft. The present report shows that both mature and immature neurofilament-immunoreactive neurons are capable of innervating the iris. Furthermore, this ingrowth can occur both in the presence and absence of normal intrinsic neurofilament-positive nerve fibers.

Animals↗
PubMed2024

Complete plastid genome of Iris orchioides and comparative analysis with 19 Iris plastomes.

Iris is a cosmopolitan genus comprising approximately 280 species distributed throughout the Northern Hemisphere. Although Iris is the most diverse group in the Iridaceae, the number of taxa is debatable owing to various taxonomic issues. Plastid genomes have been widely used for phylogenetic research in plants; however, only limited number of plastid DNA markers are available for phylogenetic study of the Iris. To understand the genomic features of plastids within the genus, including its structural and genetic variation, we newly sequenced and analyzed the complete plastid genome of I. orchioides and compared it with those of 19 other Iris taxa. Potential plastid markers for phylogenetic research were identified by computing the sequence divergence and phylogenetic informativeness. We then tested the utility of the markers with the phylogenies inferred from the markers and whole-plastome data. The average size of the plastid genome was 152,926 bp, and the overall genomic content and organization were nearly identical among the 20 Iris taxa, except for minor variations in the inverted repeats. We identified 10 highly informative regions (matK, ndhF, rpoC2, ycf1, ycf2, rps15-ycf, rpoB-trnC, petA-psbJ, ndhG-ndhI and psbK-trnQ) and inferred a phylogeny from each region individually, as well as from their concatenated data. Remarkably, the phylogeny reconstructed from the concatenated data comprising three selected regions (rpoC2, ycf1 and ycf2) exhibited the highest congruence with the phylogeny derived from the entire plastome dataset. The result suggests that this subset of data could serve as a viable alternative to the complete plastome data, especially for molecular diagnoses among closely related Iris taxa, and at a lower cost.

Iris Plant↗
PubMedDate not supplied

Serum and pancreatic immunoreactive insulin (IRI) and proinsulin-like component (PLC), serum IRI and PLC response to different stimuli in normal subjects and organic hyperinsulinism.

The serum levels of total immunoreactive insulin (IRI) and proinsulin-like component (PLC) in the fasting state and following the administration of insulin secretagogues in 5 patients with organic hyperinsulinism and age and sex matched normal subjects are reported. Diagnosis of organic hyperinsulinism could be established in all instances on the basis of the inappropriately high total serum IRI levels for the corresponding blood glucose values; such an abnormal relationship was not seen in normal subjects, and was further enhanced by insulin secretagogues. Unrestrained insulin secretion in organic hyperinsulinism was enhanced following the administration of glucose, tolbutamide, glucagon or amino acids; the last 2 stimuli are known to be ineffective in causing insulin secretion in the presence of hypoglycemia in normal subjects. Four patints had insulinomas and one probably had islet cell hyperplasia or abnormal function of islet cells. Chromatography of serum IRI to quantitate PLC is a useful adjunct to the diagnosis of organic hyperinsulinism as in the fasting state the proportion of PLC is always elevated, above the normal range of 5-22%. Following the administration of insulin secretagogues there was pronounced increase in total serum IRI in organic hyperinsulinism but the proportion of PLC generally decreased, suggesting thereby that mojor increase in IRI was due to release of stored granular IRI which is known to have a low proportion of PLC.

Adenoma, Islet Cell↗
PubMed1982

Occult iris erosion. A treatable cause of recurrent hyphema in iris-supported intraocular lenses.

A 78-year-old man underwent intracapsular cataract extraction with implantation of a Binkhorst four-loop lens. Two years later he developed recurrent hyphema, glaucoma, diffusion of blood into the vitreous, and reduction of visual acuity to 3/200. Iris fluorescein angiography demonstrated a localized network of prominent collateral vessels without fluorescein leakage above the pupil, deflection and compression of radial iris vessels by the superior lens posts, and a focal area of leakage adjacent to one of the posts. Argon laser photocoagulation obliterated the abnormal vessels in each of these areas, eliminated the recurrent hyphema and glaucoma, and permitted recovery of 20/80 visual acuity. The patient died suddenly three months after iris photocoagulation. Histopathologic study of the eye demonstrate erosion of iris stroma and displacement of iris vessels by the lens posts, as well as the vascular effects of successful photocoagulation therapy.

Aged↗
PubMed2001

Iris alteration using mechanical iris retractors.

A 74-year-old woman had a 3-port pars plana vitrectomy for a dropped nucleus after complicated phacoemulsification. Flexible nylon iris retractors were positioned to dilate the small pupil. The patient died of a pulmonary embolus 1 day after surgery. The eyeball was removed at autopsy, and pathology of the iris was investigated. Localized damage to the iris where the retractor hooks were positioned was noted, but no other alterations to the iris were observed. These findings may explain the recovery of pupil function that is common after surgery with mechanical iris retractors.

Aged↗
PubMed1983

Fluorescein angiography of the heavily pigmented iris and new dyes for iris angiography.

An inexpensive adapter mounted in front of the objective lens of a fundus camera permits routine fluorescein angiography of the heavily pigmented iris. Angiograms of these patients whose iris pigment was dense enough that standard methods of iris angiography would disclose little or no information were performed with the use of the adapter. For use in the study of the iris vasculature in the research laboratory, three dyes with spectral characteristics different from those of fluorescein allow angiography of the iris at different wavelengths. Angiograms using these dyes were performed on the eye of a cynomolgus monkey. The angiograms were each taken as close as possible to the same time sequence and show dramatically different filling and staining patterns.

Animals↗
PubMed1977

Solitary iris nevus associated with peripheral anterior synechiae and iris endothelialization.

Two middle-aged patients developed pigmented intrastromal iris nevi and an associated loss of the surrounding iris stromal markings suggestive of a surface iris membrane. Because of the fear of malignant melanoma with superficial growth, we excised the lesions. Histopathologic examination of the specimens revealed that the pigmented lesions were benign iris nevi and that the surrounding membrane was caused by endothelial cell growth onto the iris from peripheral anterior synechiae. These synechiae occurred anterior to Schwalbe's line in the same sector as the nevi and had been noted preoperatively at gonioscopic examination, but their diagnostic significance was not appreciated.

Adult↗
PubMed1994

Benign adenoma of the iris pigment epithelium: clinical and iris fluorescein angiographic features.

Benign adenoma of iris pigment epithelium is a rare neoformation characterized by a multinodular, dark brown to dark black, relatively stationary lesion, especially localized in the peripheral iris. We report a case of iris pigment epithelium adenoma with no evidence of change during the 6-year follow-up. Iris fluorescein angiography showed a mild staining of the lesion without evidence of abnormal vessels. The importance of fluorescence iridography in the differential diagnosis of iris-pigmented lesions is discussed.

Adenoma↗
PubMed1983

Endogenous levels of abscisic Acid and decanoic Acid in dutch iris bulbs and the influence of abscisic Acid and decanoic Acid on iris meristems cultured in vitro.

Abscisic acid (ABA) and decanoic acid inhibited shoot elongation and floral development of Dutch iris (Iris hollandica Hoog. cv Ideal) meristems cultured in vitro. No synergism with respect to inhibition of leaf growth between ABA and decanoic acid was observed. With monthly harvest dates, from July 10, 1981 to October 10, 1981, there was a progressive decrease in endogenous level of free ABA in ;Ideal' iris bulbs. Bulbs subjected to a full set of the usual preplanting storage conditions flowered, on average, 46 days after planting versus 194 days after planting for bulbs planted directly after harvest. ABA levels at harvest were 4- to 5-fold those after the preplanting storage treatment. In general, ABA levels did not correlate well with the length of time from planting until flowering of iris bulbs. Endogenous decanoic acid levels did not follow any pattern with respect to harvest date or postharvest treatment. After the postharvest high temperature treatment, there was about a 3-fold increase in nonscale decanoic acid concentration. Decanoic acid levels, in nonscale tissue, remained high after each of the other postharvest treatments. It is concluded that there is no good evidence to support the contention that either ABA or decanoic acid is directly involved in iris bulb dormancy.

Journal Article↗
PubMed2004

IRIS II study: the IRIS II score--assessment of a new clinical algorithm for the classification of insulin resistance in patients with Type 2 diabetes.

AIMS: With the increasing availability of new drugs for the treatment of insulin resistance in patients with Type 2 diabetes, simple methods for their identification is an important challenge. The aim of our study was to compute a new algorithm for estimating insulin resistance in a routine clinical setting. METHODS: Clinical data and blood samples were collected from 4265 Type 2 diabetic patients from 149 clinical sites. A clinical algorithm to estimate insulin resistance was developed by stepwise multiple regression analysis. The new generated score was compared with the HOMAIR-score, calculated from fasting insulin and glucose levels measured in a central laboratory. In a subgroup of 48 patients, the score was verified against a frequently sampled intravenous glucose tolerance test with subsequent modified minimal model analysis according to Bergman. RESULTS: Multiple regression analysis revealed fasting blood glucose, BMI, triglycerides and HDL as the most powerful predictors of insulin resistance which were used for further computation of the IRIS II score. A significant overall correlation was found between the HOMAIR-score and the new clinical IRIS II score (r = 0.42; P < 0.0001). Compared with HOMAIR, the new score revealed a specificity of 0.95, a sensitivity of 0.34 and a positive predictive value of 0.95. This was in good agreement with the subset analysis of the intravenous glucose tolerance test, where a sensitivity of 0.37 and a specificity of 0.85 of the IRIS II score was calculated. Patients with insulin resistance according to the IRIS II score revealed an increased odds ratio for overall vascular complications (1.28; 1.11-1.46; P < 0.001). CONCLUSIONS: The new IRIS II score can identify insulin resistance in Type 2 diabetic patients with high predictive value and high specificity.

Algorithms↗