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N Mamalis

Publications and source records attributed to N Mamalis.

89 records · Page 5Linked to original sources
PubMed1985

Histopathologic correlative study of Kelman-style flexible anterior chamber intraocular lenses.

Three of 16 eyes in which Kelman flexible anterior chamber lenses were implanted were obtained for postmortem examination, and the lenses and globes were analyzed histopathologically. Thirteen additional lenses, removed surgically secondary to various complications, were studied by scanning electron microscopy. All of the lenses ere well finished and none showed evidence of degradation or cracking of the polymethylmethacrylate optics or foot plates. Some of the lenses showed deposition of inflammatory debris or erythrocytes, reflecting a clinical history of uveitis. In some cases, the problems seemed to be related to variations in surgical technique or improper sizing.

Aged↗
PubMed1985

An analysis of semiflexible, closed-loop anterior chamber intraocular lenses.

We present the pathologic and scanning electron microscopic findings from 44 semiflexible, all polymethylmethacrylate, anterior chamber intraocular lenses (IOLs). These IOLs, which have round, small diameter, closed loops were removed following a variety of complications, including uveitis and/or the uveitis-glaucoma-hyphema syndrome, secondary glaucoma, pseudophakic bullous keratopathy, cystoid macular edema, erosion into uveal tissue (with and without oval pupil), and iris neovascularization. Over 200,000 of these lens styles have been implanted. Even though the number of these IOLs accessioned in our laboratory is small, we feel this analysis documents some of the problems that may be encountered with this IOL design. Many of the complications documented in our series resulted in severe visual loss. In addition to tissue damage that appeared secondary to the mechanical tissue-to-implant interface, other causes of complications included variations in surgical technique, implantation into eyes with preexisting disease (including eyes that had undergone previous surgery), and damage to tissue that occurred during IOL removal.

Anterior Chamber↗
PubMed1985

A comparison of ciliary sulcus and capsular bag fixation of posterior chamber intraocular lenses.

We compare indications, advantages, and disadvantages of ciliary sulcus and lens capsular bag (lens capsular sac) fixation of posterior chamber intraocular lenses (IOLs). Our findings suggest that, whenever possible, it is efficacious to implant the loops of posterior chamber IOLs within the capsular bag. This positions the lens optic and the supporting loops in the natural anatomical position, sequestered from highly vascular uveal tissue and the blood aqueous barrier. This should minimize the potential for complications that may be associated with iris-ciliary body contact. Considering the rapid increase in the number of implantations of IOLs now being performed (approximately 700,000 per year in the United States alone), a possible reduction of even 1% in clinically significant complications would make this effort worthwhile. Widespread application of in-the-bag implantation is predicated on the assumption that the surgeon is proficient with this procedure and that careful follow-up of patients does not reveal any significantly increased incidence of lens dislocation due to zonular rupture.

Adult↗
PubMed1984

Phacoanaphylactic endophthalmitis associated with extracapsular cataract extraction and posterior chamber intraocular lens.

We describe the clinicopathologic findings in a patient who underwent extracapsular cataract extraction (ECCE) with insertion of a posterior chamber intraocular lens (IOL). The patient had a sterile hypopyon and anterior uveitis that temporarily subsided but recurred. The inflammation actually worsened after removal of the IOL, and the eye was enucleated. Histopathologic examination showed a pattern consistent with phacoanaphylactic endophthalmitis. We therefore postulate that the patient's complications were due to hypersensitivity to her own lens protein, which remained after the ECCE, rather than to the IOL itself.

Aged↗
PubMed1984

Biocompatibility of implant materials: a review and scanning electron microscopic study.

The evolution of various plastic materials used in the manufacture of intraocular lenses is reviewed, with special reference to the problem of biocompatibility of lens haptic materials. To date, polypropylene has been found and continues to be a highly effective, relatively inert material, providing good surgical results. However, the present study and other morphologic and chemical studies have provided evidence that indicates long-term alteration of polypropylene may occur. For this reason we believe that further studies of this particular polymer are warranted. Also, a continuing search and trial of other plastics to discover an equivalent or even more efficacious haptic material seems desirable. There is a need for careful long-term follow-up of patients after intraocular lens implantation, particularly of young patients.

Biocompatible Materials↗
PubMed1984

Pathological and scanning electron microscopic evaluation of the 91Z intraocular lens.

We analyzed 18 explanted 91Z anterior chamber lenses by light and scanning electron microscopy. Intermittent touch of the lens loops to the posterior corneal surface and the anterior chamber angle may have occurred. Erosion of the polypropylene loops into the anterior chamber angle recess and into the iris tissue was also observed. Fibrous tissue, uveal tissue, and inflammatory debris were noted on the loops, forming dense synechias at the points of contact with the angle recess. In some lenses the edges of the optics were sharp. Other significant manufacturing defects were rarely seen, and there was no evidence of degradation of polypropylene loops. The problems regarding surgical removal of this lens are discussed.

Anterior Chamber↗
PubMed1984

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Acetates↗
PubMedDate not supplied

Complications of intraocular lenses. A historical and histopathological review.

Recent improvements in intraocular lens (IOL) design, manufacturing techniques, and surgical techniques have greatly reduced the incidence of complications following implantation, and many authors now consider IOL implantation to be among the most safe and effective major surgical procedures. However, adverse reactions are still seen--some as late sequelae of earlier IOL designs and implantation techniques and some as sequelae of more recent implantations using "state-of-the-art" lenses and surgical techniques. Complications may be due to various factors, including surgical technique, IOL design, or the inability of some eyes with preexisting disease to tolerate an implant. The authors trace the evolution of IOLs since Ridley's first implant, summarizing the modifications in lenses and surgical techniques that were made as complications were recognized. They then review the clinical and histopathological features of selected cases from more than 200 IOLs and/or globes removed due to IOL-related complications and studied in the University of Utah Ocular Pathology Laboratory. It is hoped that this review will provide insights into the pathogenesis of IOL complications, enhancing the current success of implant procedures and stimulating further basic and clinical research in this area.

Anaphylaxis↗
PubMedDate not supplied

Congenital orbital teratoma: a review and report of two cases.

Congenital orbital teratomas are rare tumors derived from more than one germinal cell layer. These tumors may arise within the orbit, or may originate intracranially and extend into the orbit. Recent advances in ultrasonography have made in utero diagnosis possible. We present the case reports of a primary orbital teratoma and an intracranial teratoma with secondary orbital involvement. The clinical features, histopathologic findings, treatment, and pathogenesis of orbital teratomas are discussed.

Adolescent↗
PubMedDate not supplied

Nodular fasciitis presenting as a rapidly enlarging episcleral mass in a 3-year-old.

A rapidly enlarging periocular mass in a child obligates the treating physician to rule out a malignancy, especially a rhabdomyosarcoma. A 3-year-old girl presented with a 5-day history of a rapidly growing episcleral mass superonasal to the globe, adjacent to the superior rectus muscle insertion. The lesion was locally excised. A sarcoma could not be excluded on frozen sections. Permanent sections and electron microscopy revealed nodular fasciitis, a benign lesion with a pseudosarcomatous histologic appearance. No recurrence has been noted at 9 months follow-up. Nodular fasciitis is a benign proliferation which should be considered in the differential diagnosis of a rapidly enlarging subconjunctival or orbital mass in a child.

Child, Preschool↗
PubMedDate not supplied

Exophiala werneckii endophthalmitis following cartaract surgery in an immunocompetent individual.

A case of infectious endophthalmitis caused by the saprophyte Exophiala werneckii is reported. This has not been recognized as a pathogen for ocular infections previously. The infection followed uncomplicated cataract surgery involving phacoemulsification and IOL implant. Clinical presentation was that of an indolent endophthalmitis with relatively acute onset. Pars plana vitrectomy, fungal stains, and culture established the diagnosis. Initial management consisted of empirical intravitreal injection of vancomycin, ceftazidime, and amphotericin B. Treatment was supplemented with a 3-week course of systemic fluconazole and topical therapy with natamycin, atropine, ciprofloxacin, and diclofenac. The visual acuity returned to 20/20-2 with no recurrence of infection. The source of the infection could not be determined. Fungal endophthalmitis has to be considered as a rare, though important, complication following ophthalmic surgery. Specific fungal stains and cultures are helpful for establishing the diagnosis early in the course of disease. E werneckii should be considered in the differential diagnosis of fungal endophthalmitis.

Aged↗
PubMedDate not supplied

Nodular cutaneous amyloid tumors of the eyelids in the absence of systemic amyloidosis.

A patient was referred with recurrent bilateral, slow-growing, painless, nodular tumors of the upper eyelid margins. The tumors were excised and the base of each lesion was ablated with the CO2 laser. Histological examination of the excised tissue revealed amyloid. Despite the fact that cutaneous, amyloid lesions of the eyelid have been previously described as essentially pathognomonic for systemic amyloid disease, no evidence of systemic amyloidosis was found in this patient. We believe that this represents only the second reported case of bilateral cutaneous amyloid of the eyelids without systemic involvement. We agree with previous authors that this lesion be added to the list of painless slow-growing bilateral eyelid tumors.

Amyloidosis↗
PubMedDate not supplied

Radial keratotomy in a patient with keratoconus.

A 33-year-old patient had radial keratotomy performed on both eyes for relief of longstanding myopia. Minimal reduction of myopia was obtained, and the patient underwent a second radial keratotomy in both eyes. Best corrected visual acuity decreased, and the patient had a marked, irregular astigmatism postoperatively. Careful ophthalmologic evaluation revealed that the patient had keratoconus bilaterally. Following a failed trial of contact lens wear, the patient underwent a penetrating keratoplasty of the right eye. Pathologic evaluation revealed findings of keratoconus, as well as radial keratotomy scars. This case report illustrates the importance of a complete ophthalmologic examination possibly including videokeratography, prior to keratorefractive surgery.

Adult↗
PubMedDate not supplied

Subcapsular fluid entrapment in extracapsular cataract surgery.

We report five cases of sudden shallowing of the anterior chamber associated with irrigation under the iris. We suspect that irrigation in this context forces fluids through the zonules into the posterior chamber, where it becomes trapped, causing anterior chamber shallowing. In our cases, this phenomenon was most commonly associated with irrigation during cortex removal in cases in which the cornea was open (associated with corneal transplantation) and with zonular dehiscence.

Anterior Chamber↗
PubMedDate not supplied

Malignant transformation of a necrotic melanocytoma of the choroid in an amblyopic eye.

A 26-year-old man presented with an insidious loss of vision OD. He had amblyopia OD as a child secondary to congenital esotropia. Ophthalmic examination revealed a large mass beneath his right retina near the posterior pole. He also had glaucoma and a rapidly developing cataract. Ultrasound detected a choroidal mass, which was consistent with a melanoma. The patient chose enucleation over radiation therapy as his treatment modality. Pathologic evaluation of the tumor revealed a necrotic melanocytoma with a large malignant melanoma arising from its center that was comprised mainly of epithelioid cells. Malignant melanoma arising in a necrotic melanocytoma is an extremely rare event, and we believe this to be the first description of this event in a young patient with an amblyopic eye.

Adult↗
PubMedDate not supplied

Ocular melanoma.

Uveal melanoma is the second most frequent ocular malignancy after metastasis and the most common primary ocular malignant neoplasm in adults. The diagnosis is usually made from clinical examination and ocular ultrasound. CT and MR may be helpful for further evaluation.

Aged↗