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PubMed1983

The differential diagnosis of malignant melanoma of the iris. A clinical study of 200 patients.

The records of 200 consecutive patients referred to the Ocular Oncology Service of Wills Eye Hospital because of an iris lesion suspected of being an iris melanoma were reviewed. On clinical evaluation, 24% of the lesions met the criteria for the diagnosis of iris melanoma and 76% were diagnosed as simulating lesions (pseudomelanomas). The most common pseudomelanomas included primary iris cyst (38%), iris nevus (31%), essential iris atrophy (5.7%), iris foreign body (4.5%), peripheral anterior synechia (2.5%), and iris metastasis (2.5%). Less frequently encountered pseudomelanomas included aphakic iris cysts, leiomyoma, melanocytoma, reactive lymphoid hyperplasia, adenoma of iris pigment epithelium, iridoschisis, and other miscellaneous entities. The clinical features that are helpful in differentiating the more common iris pseudomelanomas from true melanomas are discussed. Correct clinical identification of these simulating lesions may prevent unnecessary surgery or other treatment.

Adenoma↗

PubMed1993

Influence of silicone oil on iris microangiopathy in diabetic vitrectomized eyes.

PURPOSE: This study evaluates the influence of intraocular silicone oil on iris diabetic microangiopathy in diabetic vitrectomized eyes. METHODS: The authors examined 20 eyes of 20 patients with diabetes undergoing primary vitrectomy for fractional diabetic retinal detachment, endophotocoagulation, and 1000 centistokes silicone oil tamponade. The vascular status of the iris in these eyes was examined by iris fluorescein angiography once before silicone oil injection and again when it was removed (mean follow-up, 8.3 months). RESULTS: Iris diabetic microangiopathy, including breakdown of the blood-iris barrier and iris neovascularization, improved or remained stable in 40% of eyes. It worsened in 60% of eyes, including all aphakic eyes. Neovascular glaucoma developed in one of them. A significant correlation was found between worsening of iris diabetic microangiopathy and both aphakia (P = 0.01) and severe immediate postvitrectomy inflammation (P = 0.02). Eyes with recurrent retinal detachment (n = 4) showed worsening of iris diabetic microangiopathy, but this was not significantly correlated. CONCLUSION: Aphakic vitrectomized eyes have a higher risk of iris diabetic microangiopathy developing, even after silicone oil tamponade. Immediate postoperative intraocular inflammation also is a risk factor for worsening of iris diabetic microangiopathy in phakic eyes. Recurrence of retinal detachment was not significantly correlated with worsening of iris status.

Adult↗

PubMed1997

Photodynamic therapy and digital angiography of experimental iris neovascularization using liposomal benzoporphyrin derivative.

PURPOSE: To study the efficacy of liposomal benzoporphyrin derivative (BPD) (Verteportin) for the angiographic visualization and photodynamic therapy (PDT) of experimental iris neovascularization. METHODS: Experimental iris neovascularization was induced in eight cynomolgus monkey eyes by occluding all the branch retinal veins with a dye-yellow (577-nm) laser. Iris angiography was done with sodium fluorescein, indocyanine green (ICG), and liposomal BPD to compare the visualization of normal and neovascular vessels by these three dyes. PDT was performed using an intravenous infusion of liposomal BPD (0.375-0.75 mg/kg), followed by irradiation with 689-nm light from a diode laser/slit-lamp delivery system using 600 mW/cm2 irradiance and 150 J/cm2 fluence. The effect of treatment was followed by iris photography and angiography, and the findings were confirmed by histopathology using light and electron microscopy. RESULTS: Iris fluorescein angiography (FA) showed superficial tortuous and leaky new vessels. Liposomal BPD and ICG angiography of the same eye demonstrated deeper dilated and tortuous iris vessels, with minimal dye leakage. PDT of the iris with irradiation, performed within 20 minutes of the start of dye infusion (0.75 mg/kg), resulted in angiographic and histologic occlusion of iris vessels examined at 24 hours. Three to nine days after PDT, histopathologic examination showed regression of the iris neovascular membrane, with some open vessels. CONCLUSIONS: Liposomal BPD and ICG provided angiographic visualization of deeper normal and neovascular iris vessels. PDT using liposomal BPD leads to effective early closure to experimental iris neovascularization.

Angiography, Digital Subtraction↗

PubMed2006

[Iris mammillations: three case reports].

INTRODUCTION: Iris mammillations are congenital abnormalities characterized by vitiliform protuberances regularly spaced on the surface of a velvety iris. They can be either isolated or associated with melanocytosis involving iris, sclera or periocular tissues, resulting in a risk for uveal melanoma. They can be complicated by ocular hypertension. We report three cases of iris mammillations in three children. CASES REPORT: For each patient, age, circumstances of revelation, anterior and posterior segment examination, intraocular pressure, associated anomalies, and progression were noted. Patient no. 1: In a 13-month-old boy examined for a squint, bilateral iris mammillations were fortuitously discovered. Intraocular pressure remained normal over 22 months of follow-up. Patient no. 2: In an eight-year-old boy, bilateral iris mammillations with papillary excavation were fortuitously discovered. Intraocular pressure was normal and the excavation did not change over 20 months of follow-up. Patient no. 3: A five-year-old boy was examined for a scleral pigmentation in the right eye. The examination found unilateral iris mammillations and ipsilateral ocular melanocytosis. Intraocular pressure and fundus were normal and remained normal over 13 months of follow-up. DISCUSSION: and conclusion: Iris mammillations are congenital abnormalities, generally unilateral, sometimes hereditary. The differential diagnosis includes Lisch nodules of neurofibromatosis and iris melanoma. The etiology of iris mammillations is unknown; these lesions can be complicated by ocular hypertony and, in case of associated melanocytosis of the iris, sclera or periocular tissues, by uveal melanoma. These potential complications warrant a regular clinical follow-up.

Child↗

PubMed2002

Effect of squalamine on iris neovascularization in monkeys.

PURPOSE: To investigate the effect of squalamine, an antiangiogenic aminosterol, in an experimental model of iris neovascularization. METHODS: Iris neovascularization was created in cynomolgus monkeys by occluding retinal veins with an argon laser and inducing persistent hypotony with a central corneal suture. Twenty-four eyes were treated in three groups. In Group 1, four eyes were injected intravitreally with 3 microg/0.1 mL squalamine and four eyes with balanced saline solution (controls) immediately after vein occlusion (day 1); injections were repeated every 3 days for 3 weeks. In Group 2, 1 mg/kg squalamine was administered with intravenous infusion in dextrose 5% in four animals; four control animals received only dextrose. Infusions began on day 1 and were repeated every 3 days for 3 weeks. In Group 3, after development of iris neovascularization on day 7, 1 mg/kg squalamine was injected systemically in four animals; four control animals received dextrose 5%. Monkeys were examined by slit-lamp biomicroscopy and underwent color photography and fluorescein angiography. RESULTS: Group 1: All eyes, treated and control, developed intense and persistent rubeosis iridis. Group 2: Two of the four treated eyes in this group developed minimal iris neovascularization; the other two had no iris neovascularization. All four control eyes developed intense, persistent iris neovascularization. Group 3: All eyes developed extensive rubeosis iridis; iris neovascularization regressed in all four treated eyes after squalamine injections. Two of four treated eyes retained minimal iris neovascularization; two showed complete regression of rubeosis iridis. Rubeosis iridis completely regressed in two of the four control eyes; the remaining two control eyes had intense, persistent iris neovascularization. CONCLUSIONS: Intravitreally injected squalamine did not affect the development of iris neovascularization; however, systemic squalamine injection inhibited the development of iris neovascularization and caused partial regression of new vessels in a primate model.

Angiogenesis Inhibitors↗

PubMed1995

Treatment of non-resectable malignant iris tumours with custom designed plaque radiotherapy.

BACKGROUND: Plaque radiotherapy is the most common method of managing posterior uveal melanoma but its use for iris melanoma and iris metastases has not yet been evaluated. METHODS: Fourteen patients with non-resectable iris melanoma and four with iris metastasis were treated with plaque radiotherapy. The tumour response to treatment and the local side effects of the radioactive plaque were evaluated. RESULTS: In the iris melanoma group over a mean follow up of 26 (range 6-75) months, the tumour regressed in 13 of the 14 patients (93%) and recurred as diffuse seeding in one patient (7%). Despite large doses of radiation given transcorneally, the cornea developed epitheliopathy, abrasion, and oedema in only one case each. The major radiation side effects were localised iris vasculopathy without glaucoma in two cases, posterior synechiae in five cases, and cataract in six cases. In the iris metastasis group, tumour regression was observed in all four patients (100%) and radiation side effects were not evident over the relatively short mean follow up period of 8 (range 4-9) months. All of the 14 patients with irradiated iris melanoma have remained systemically healthy without metastasis while three of the four patients with irradiated iris metastases have died of metastases from the primary neoplasm. CONCLUSION: Custom designed plaque radiotherapy appears to be an effective alternative method of controlling non-resectable diffuse iris melanoma and solitary iris metastasis and has relatively few side effects.

Brachytherapy↗

PubMed1998

Interferon gamma immunoreactivity in iris nerve fibres during endotoxin induced uveitis in the rat.

AIMS: Previous studies have implied that interferon gamma (IFN-gamma) is involved in the pathogenesis of endotoxin induced uveitis (EIU) in the rat. This study investigated the source of IFN-gamma in the iris during EIU. METHODS: Whole mounts of iris were isolated from Lewis rats before and at different times (from 4 hours to 14 days) after foot pad injection of 200 micrograms Salmonella typhimurium lipopolysaccharide (LPS). Immunohistological analysis was performed using monoclonal antibodies (mAbs) specific to rat IFN-gamma (DB12 and DB13). mAbs specific to monocytes, macrophages, and dendritic cells and MHC class II were used to asses the inflammatory response in the eye (ED-1, ED-2, and OX-6). An antibody specific to neurofilaments (2H3) was used to stain nerve fibres in the normal iris. RESULTS: LPS administration induced acute intraocular inflammation, characterised by a massive infiltration of monocytes/macrophages and increased numbers of MHC class II positive cells in the iris. IFN-gamma immunoreactive cells were not detected in iris whole mounts of control rats. Strikingly, IFN-gamma immunoreactivity was found in fibres from 4 hours until 10 days after LPS injection, with the most intense staining at 48-72 hours. Other DB12 or DB13 positive cells were not detected in the iris. The pattern of DB12 and DB13 staining in the inflamed iris was similar to the 2H3 staining of neurons in the iris of control rats. CONCLUSION: These results show that systemic LPS administration induces IFN-gamma immunoreactivity in iris fibres and suggest that iris nerve fibres may be a source of IFN-gamma during EIU. The IFN-gamma immunoreactive material in the iris nerve fibres may be identical to neuronal IFN-gamma.

Animals↗

PubMed2005

Iris-derived cells from adult rodents and primates adopt photoreceptor-specific phenotypes.

PURPOSE: The purpose of this study was to investigate the effects of various genes related to photoreceptor development on rodent and primate iris cells and the potential of iris cells as donor cells for retinal transplantation. METHODS: Adult rat and monkey iris tissue were cultured in serum-free medium containing basic fibroblast growth factor. Gene deliveries of Crx, Nrl, NeuroD and some combinations (Crx-Nrl, Crx-NeuroD) were performed with recombinant retrovirus. Immunocytochemistry, Western blot analysis, RT-PCR, and intracellular recording were used to examine the expression of photoreceptor-specific phenotypes in the iris-derived cells after gene transfer, . Coculture of the iris-derived cells with embryonic retinal explant was conducted, to investigate the potential integration of these cells in coculture conditions. RESULTS: Misexpression of Crx induced adult rat iris cells to express several photoreceptor-specific antigens and transcripts, such as rhodopsin, recoverin, cGMP-gated channel, arrestin, interphotoreceptor retinal-binding protein, rhodopsin kinase, and NeuroD. In primates, a combination of Crx and NeuroD was needed to induce monkey iris-derived cells to adopt photoreceptor-specific phenotypes. Furthermore, the photoreceptor-like cells derived from both rat- and primate-iris tissues showed rod photoreceptor-specific electrophysiological response to light stimuli after Crx and Crx-NeuroD gene transfer, respectively. The results further showed that iris-derived cells integrated in the developing host retina in coculture conditions. CONCLUSIONS: Adult iris-derived cultured cells of both rodents and primates expressed photoreceptor-specific phenotypes by inductions of transcription factors. These iris-derived photoreceptor-like cells have electrophysiological characteristics of rod photoreceptors. Furthermore, they can integrate in the developing retina under coculture conditions.

Animals↗

PubMed1998

Fluorescein angiography and indocyanine green videoangiography in the iris of pseudoexfoliation syndrome.

The precise evaluation of iris vascular pattern in pseudoexfoliation syndrome (PXS) may be difficult on iris fluorescein angiography (IFA) because of the frequent presence of a heavily pigmented iris and late conspicuous leakage. Thanks to its special characteristics, iris indocyanine green videoangiography (IICGV) is able precisely to visualize details of the iris vascular pattern. The aim of the study is to analyze the feasibility of IICGV in detecting microvascular changes in PXS and compare these findings with those of IFA. Twenty-eight patients affected in both eyes by PXS underwent an ophthalmologic examination including IFA and IICGV. IICGV was performed using IMAGEnet system H1024. A better visualization of iris hypoperfusion and anastomotic vessels was obtained on IICGV, whereas iris microneovascularization was far more clearly visible on IFA. Moreover, iris pigment epithelium defects were detectable on IICGV. IICGV may be considered a useful tool in the evaluation of the iris vascular pattern in PXS. Iris hypoperfusion could not play a contributory role in the development of iris microvascular changes.

Aged↗

PubMed1983

Interactions between the sympathetic and sensory innervation of the iris.

The interaction between peptidergic, sensory nerves and sympathetic fibers was examined in the rat iris. The putative peptide neurotransmitter, substance P, was used as an index of the sensory innervation, because the peptide is exclusively localized in the iris to trigeminal sensory fibers. Extirpation of the sympathetic, superior cervical ganglion resulted in an increase in iris content of substance P-like immunoreactivity (henceforth SP), suggesting that sympathetic terminals influence the peptidergic sensory innervation of the iris. The increase in iris peptide after sympathetic ganglionectomy was reversed by implantation of sympathetic ganglia into the anterior chamber of the eye. Pharmacological stimulation or blockade of sympathetic nerve impulse activity and pharmacological blockade of sympathetic axonal transport did not alter iris peptide, suggesting that these procedures did not mediate the sympathetic-sensory interaction. However, injection of nerve growth factor (NGF) systemically or into the anterior chamber increased iris peptide, reproducing the effects of ganglionectomy. Conversely, injection of antiserum to NGF (anti-NGF) into the anterior chamber decreased iris SP suggesting that endogenous trophic protein normally regulates sensory peptide. The effects of anti-NGF were transitory; iris peptide returned to normal after cessation of treatment. Consequently, anti-NGF administration apparently did not lead to sensory neuron destruction, but rather altered either the number of sensory fibers in the iris or the amount of peptide per fiber. Finally, injection of anti-NGF into the anterior chamber reversed the effects of sympathetic ganglionectomy, suggesting that NGF may mediate the sympathetic-sensory interaction. Our observations suggest that competition for target NGF may result in reciprocal regulation of the iris sympathetic and sensory innervation.

Adrenergic Fibers↗

PubMed1975

Iris nevus (Cogan-Reese) syndrome. A cause of unilateral glaucoma.

Fourteen patients (ten women, four men) with iris nevus (Cogan-Reese) syndrome, all having unilateral glaucoma, were studied clinically. Many had corneal edema, and all had changes in the iris consisting of one or more of the following: iris whorls or nodules or both, atrophy of iris stroma, heterochromia (the darker iris usually involved), or ectropion uveae. All had peripheral anterior synechias. Material for histological study was available from ten patients and showed a nonmalignant diffuse nevus of the anterior surface of the iris. An overgrowth of endothelium and Descemet membrane extending onto the iris surface may be a characteristic part of the process. Patients tended to be women in middle age. Conservative treatment avoiding enucleation is advised. Whenever a patient with suspected iris nevus syndrome or essential iris atrophy is subjected to glaucoma surgery, a biopsy specimen of the iris should be obtained for histological study.

Adolescent↗

PubMed2005

Potential roles for BMP and Pax genes in the development of iris smooth muscle.

The embryonic optic cup generates four types of tissue: neural retina, pigmented epithelium, ciliary epithelium, and iris smooth muscle. Remarkably little attention has focused on the development of the iris smooth muscle since Lewis ([1903] J. Am. Anat. 2:405-416) described its origins from the anterior rim of the optic cup neuroepithelium. As an initial step toward understanding iris smooth muscle development, I first determined the spatial and temporal pattern of the development of the iris smooth muscle in the chick by using the HNK1 antibody, which labels developing iris smooth muscle. HNK1 labeling shows that iris smooth muscle development is correlated in time and space with the development of the ciliary epithelial folds. Second, because neural crest is the only other neural tissue that has been shown to generate smooth muscle (Le Lievre and Le Douarin [1975] J. Embryo. Exp. Morphol. 34:125-154), I sought to determine whether iris smooth muscle development shares similarities with neural crest development. Two members of the BMP superfamily, BMP4 and BMP7, which may regulate neural crest development, are highly expressed by cells at the site of iris smooth muscle generation. Third, because humans and mice that are heterozygous for Pax6 mutations have no irides (Hill et al. [1991] Nature 354:522-525; Hanson et al. [1994] Nat. Genet. 6:168-173), I determined the expression of Pax6. I also examined the expression of Pax3 in the developing anterior optic cup. The developing iris smooth muscle coexpresses Pax6 and Pax3. I suggest that some of the eye defects caused by mutations in Pax6, BMP4, and BMP7 may be due to abnormal iris smooth muscle.

Actins↗

PubMed2004

Ophtec iris reconstruction lens United States clinical trial phase I.

PURPOSE: To determine the safety and efficacy of the Ophtec model 311 iris reconstruction lens for treatment of visual disturbances, such as glare or photophobia, related to partial or total absence of the human iris. DESIGN: Phase I multicenter, nonrandomized, investigational device study. PARTICIPANTS: Ten iris reconstruction lenses were placed in 10 subjects at 6 sites. METHODS: Iris reconstruction lenses were placed in 9 patients who had lost all or part of their iris from trauma and in 1 patient who lacked iris pigmentation due to congenital albinism. Patients were examined preoperatively, intraoperatively, and postoperatively at day 1; week 1; and months 1, 3, 6, and 12. MAIN OUTCOME MEASURES: Efficacy measures were uncorrected visual acuity (UCVA), glare, starbursts, and photophobia. Safety measures were best-corrected visual acuity (VA), surgical complications, and adverse events. RESULTS: Uncorrected VA improved in all eyes after implantation of the iris reconstruction lens. Best-corrected VA did not change significantly (P = 0.24). Postoperative photophobia was reduced in all 9 eyes that experienced moderate to severe preoperative photophobia. Likewise, postoperative glare was reduced in all 6 eyes with moderate to severe preoperative glare. There were no surgical complications. Adverse events included 2 cases of iritis and 1 case of macular edema. CONCLUSIONS: Preliminary results suggest that the Ophtec model 311 iris reconstruction lens can improve UCVA and reduce glare and photophobia in patients with partial or total absence of the iris or iris pigmentation.

Adult↗

PubMed1992

Iris neovascularization in proliferative vitreoretinopathy.

PURPOSE: The purpose of this study is to report on the prevalence, incidence, and associated risk factors of iris neovascularization in nondiabetic patients undergoing vitrectomy for retinal detachment complicated by proliferative vitreoretinopathy (PVR). METHODS: The authors conducted a retrospective review of 141 consecutive non-diabetic patients undergoing vitrectomy for recurrent retinal detachment resulting from PVR. Univariate and multivariate analyses were performed on all patients to determine which preoperative, intraoperative, and postoperative factors were associated with the development of postoperative iris neovascularization. RESULTS: Twenty-seven of the 141 (19%) patients were noted with preoperative and/or postoperative iris neovascularization. Four of eight patients presenting with preoperative iris neovascularization had complete regression after successful reattachment of the retina. Results of analysis of the remaining 133 patients without iris neovascularization preoperatively showed residual retinal detachment as the most significant risk factor for postoperative iris neovascularization. In the absence of panretinal photocoagulation, none of the 27 patients developed neovascular glaucoma. CONCLUSIONS: The development of iris neovascularization preoperatively or post-operatively is not necessarily a predictor of a poor anatomic and/or visual result. Iris neovascularization in PVR rarely if ever progresses to neovascular glaucoma. Panretinal photocoagulation is not indicated in these patients. Retinal reattachment is the most important factor in the prevention and/or resolution of postoperative iris neovascularization. The development of iris neovascularization in PVR appears to be a multifactorial process requiring multiple variables acting in concert.

Adolescent↗

PubMed1995

Prevention of blinking alters iris configuration in pigment dispersion syndrome and in normal eyes.

PURPOSE: To examine the effect of blinking on iris configuration and aqueous humor distribution between the posterior and anterior chambers in eyes with pigment dispersion syndrome compared with healthy eyes. METHODS: High-resolution, anterior segment ultrasound biomicroscopy was performed on ten eyes of ten patients with untreated pigment dispersion syndrome and on ten control subjects. Patients were scanned continuously for 15 minutes or until the maximal change in iris configuration occurred. During this time, the eyelids were held open mechanically, and blinking was prevented. Eyes then were rescanned immediately after blinking. RESULTS: Initial iris configuration was concave in all eyes with pigment dispersion syndrome, whereas in control eyes it was concave in four eyes, planar in four eyes, and convex in two eyes. Iridozonular contact occurred in eyes with pigment dispersion syndrome only. Iridolenticular contact was greater in eyes with pigment dispersion syndrome than in control eyes. Analysis of covariance controlling for age, sex, and refractive error showed pigment dispersion syndrome to be a significant predictor of increased iris concavity. During continuous scanning, the mean change in iris position, from most concave to most convex, and mean time to the maximal change in iris configuration were greater for eyes with pigment dispersion syndrome than in control eyes and were related to the degree of initial iris concavity only (analysis of covariance). In six eyes with pigment dispersion syndrome, the eye cup was removed, normal blinking was permitted, and the eye was rescanned. The iris resumed a concave configuration in all eyes. CONCLUSION: Increased iris concavity in pigment dispersion syndrome appears to be related to increased iridolenticular contact. This creates an anatomic configuration that predisposes to reverse pupillary block. The accumulation of aqueous humor in the posterior chamber, when blinking is prevented, alters iris position in pigment dispersion syndrome and in healthy eyes and increases iridozonular and iridociliary-process distances while minimizing iridolenticular contact. Normal blinking appears to create transient vector forces which promote aqueous humor flow from the posterior to anterior chamber.

Adult↗

PubMed1987

Iris atrophy with hypoperfusion and microneovascularisation.

A series of 17 patients with stromal atrophy, hypoperfusion, and microneovascularisation of the iris investigated in the Glaucoma Investigation and Research Unit are described, and their iris angiograms were compared with those of normal irides of patients in the same age group seen in general clinics. In all but one of the 17 cases this iris atrophy was associated with glaucoma or ocular hypertension, which appeared to be secondary to the iris changes. The condition was bilateral and presented a typical slit-lamp appearance, with subtle evidence of microneovascularisation. There was neither history nor clinical evidence of previous trauma, heterochromia, or intraocular inflammation. The commonest form of iris atrophy affected the inner third of the iris stroma in a patchy manner, often with sparing above. However, diffuse atrophy occurred in two cases, and there were two cases of 'senile tears' of the iris. Some accompanying atrophy of the pigment epithelium was usual but less prominent. The changes on fluorescein angiography of the iris included the late appearance of dye with a long arteriovenous circulation time, fewer arteries than normal with sectorial hypoperfusion, leakage of dye from the pupil margin and peripupillary neovascularisation, stromal tufts, and sometimes more complex stromal microneovascularisation. An expanded prominent lesser vascular circle was a common feature of the condition. The condition is bilateral and distinct from other forms of iris atrophy. In all cases the iris changes appeared to be secondary to the vascular hypoperfusion and were not consistently associated with evidence of gross vascular disease. All patients had grey (blue) irides, and this may be an aetiological factor. The condition appears common enough to form a significant group of glaucoma patients and to be a separate clinical entity.

Aged↗

PubMed1987

Distribution and properties of beta-adrenergic receptors in human iris-ciliary body.

beta-Adrenergic receptors from the iris-ciliary body of human eyes removed shortly after death were studied using membranes prepared by isopycnic centrifugation of tissue homogenates. This procedure separates uveal melanin pigment from plasma membranes and reduces nonspecific binding of 125I-iodopindolol. The observed binding of 125I-iodopindolol was of high affinity (Kd = 78 +/- 6.6 pM), saturable, and fully reversible (t1/2 = 4.6 min). Scatchard plots were linear and revealed a Bmax of 134 +/- 20 fmol/mg of protein from the whole iris-ciliary body. The affinities of the receptors for a series of agonists and antagonists were determined. The order of potency for the inhibition of the binding of the radioligand by antagonists was ICI 118,551 greater than MK950 greater than propranolol greater than ICI 89,406 greater than metoprolol. This order of potency is characteristic of beta-adrenergic receptors of the beta 2 subtype. Preparations of iris-ciliary body were also subjected to microdissection prior to density gradient centrifugation to permit the study of beta-adrenergic receptors in the ciliary processes, ciliary body, and iris. Each of these regions was found to contain approximately one third of the total number of beta-adrenergic receptors in the human iris-ciliary body. The highest density of receptors was located in the ciliary processes (180 +/- 40 fmol/mg of protein), while the density of receptors in the iris (98 +/- 7.5 fmol/mg of protein) and ciliary body (less the processes) (42 +/- 17 fmol/mg of protein) was notably lower. Only beta 2-adrenergic receptors are detectable by competition experiments in the iris-ciliary body as a whole, or in the individual preparations of iris, ciliary processes, or ciliary body; however, microdissection and analysis of beta-adrenergic receptor subtypes in isolated ciliary muscle permitted detection of a small number of beta 1-adrenergic receptors. beta 1-Adrenergic receptors comprised about 10% of the total number of beta-adrenergic receptors in the whole iris-ciliary body. The finding that most of the beta-adrenergic receptors in the human iris-ciliary body are of the beta 2 subtype may be of significant therapeutic importance in the medical management of glaucoma.

Adolescent↗

PubMed1981

Primary cysts of the iris.

This paper has presented the author's experience with the evaluation and follow-up of 62 patients with primary cysts of the iris. On the basis of these observations, a classification of iris cyst is proposed. Accordingly, primary iris cysts are divided into epithelial and stromal categories, each having different clinical characteristics. Epithelial cysts arise between the pigmented epithelial layers of the iris and occur at the pupillary margin (central cysts), in the mid-portion of the iris (midzonal cysts) or, more commonly, in the iridociliary sulcus (peripheral cysts). In some cases, the cysts apparently break free from their epithelial attachment and migrate into the anterior chamber of vitreous chamber (dislodged cysts). Primary stromal cysts occur within the iris stroma and are not directly continuous with the posterior epithelium. They apparently arise from ectopic surface epithelium which is trapped in the iris during embryologic development. A study of the natural course and complications of these lesions has shown that the great majority of primary iris cysts, particularly those which arise from the iris pigment epithelial layer, are stationary lesions which rarely progress or cause visual complications. This finding is contradictory to the contemporary belief of certain authorities who stress that many such lesions lead to severe complications with blindness and loss of the eye. The natural course of primary epithelial cysts differs from that of secondary iris cysts which follow surgical or non-surgical trauma. The latter lesions do frequently enlarge and lead to severe complications such as inflammation and glaucoma.

Adolescent↗