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Biomedical subjects

N Mamalis

Publications and source records attributed to N Mamalis.

At least 19 recordsLinked to original sources
PubMed1995

Effect of intraocular lens size on posterior capsule opacification after phacoemulsification.

Posterior capsule opacification (PCO) is one of the most common complications of phacoemulsification with intraocular lens (IOL) implantation. This retrospective study evaluated the incidence of neodymium: YAG (Nd:YAG) laser capsulotomies for PCO in two groups of patients with different sizes of poly(methyl methacrylate) (PMMA), capsular bag-fixated IOLs. We evaluated 437 eyes that had phacoemulsification with continuous curvilinear capsulorhexis over a four-year period. Patients were placed in one of two groups, based on IOL size: large IOL (lens length 13.5 mm or greater) and small IOL (lens length less than 13.5 mm). In the large IOL group, 106 of 280 patients (38%) required YAG laser posterior capsulotomy; in the small IOL group, 25 of 157 patients (16%) did. This difference was statistically significant even though the average follow-up was 84.1 weeks in the large IOL group and 54.1 weeks in the small IOL group.

Cataract↗
PubMed1994

Crystallization on intraocular lens surfaces associated with the use of Healon GV.

OBJECTIVE: To describe a series of patients who had visually significant crystalline deposits on their intraocular lenses during cataract surgery with the use of Healon GV (a high concentration and high molecular-weight hyaluronate sodium). METHODS: Patients were examined for crystalline deposits on their intraocular lenses. These deposits were compared with intraocular lens type, viscoelastic solutions, any other intraocular substance used, type of surgery, and perioperative medications. RESULTS: In the 11 patients with documented changes (six photographically), the only consistent finding was the use of Healon GV. Furthermore, since we discontinued the use of Healon GV, we have not seen a recurrence of these deposits in more than 500 consecutive patients. The deposits could last a long time (at least 6 months) if sequestered by the posterior capsule, and they are believed to be visually significant at times (Snellen visual acuity of 20/40 or worse). CONCLUSION: Healon GV use is associated with a new clinical finding of crystalline deposits on intraocular lenses. These deposits can be clinically significant.

Aged↗
PubMed1994

Primary adenoid cystic carcinoma of the lacrimal sac: report of a case.

A 41-year-old white woman presented with a 1-month history of epiphora and a painless medial canthal mass on the left that was unresponsive to antibiotic treatment. Computerized tomography (CT) and magnetic resonance imaging (MRI) scans delineated a soft tissue mass with bony destruction originating in the area of the left lacrimal sac with extension into the maxillary and ethmoid sinuses and inferomedial orbit. Open biopsy of the mass revealed adenoid cystic carcinoma (ACC). On surgical exploration, the tumor was found to originate from the lacrimal sac wall. Radical surgery with wide excision of surrounding bone and periorbital tissue was performed in light of the histological diagnosis and tumor extension. Orbital exenteration was not performed in order to preserve the patient's left eye. A 6-week course of adjunctive radiotherapy was applied without complication. The patient was clinically and radiologically free of tumor at 1-year follow-up. This case represents only the third time that primary ACC arising from the lacrimal sac has been reported.

Adult↗
PubMed1994

Embryonal rhabdomyosarcoma of the orbit in a 35-year-old man.

A 35-year-old man had rapidly progressive proptosis of the right eye with associated chemosis over a period of several weeks. Computed tomography demonstrated a solid extraconal mass in the inferior anterior right orbit. Pathologic examination revealed the lesion to be an embryonal rhabdomyosarcoma. Consistent with the diagnosis, immunohistochemical assays demonstrated positive staining with myoglobin, desmin, and muscle-specific actin. The lesion grew rapidly and was further surgically excised. Subsequently, treatment with radiation and chemotherapy was initiated. Primary embryonal rhabdomyosarcoma of the orbit is an extremely rare tumor in adults, and, to our knowledge, this patient represents the oldest individual reported to have developed such a tumor, as documented by immunohistochemical analysis.

Adult↗
PubMed1992

Changing trends in the indications for penetrating keratoplasty.

The indications for penetrating keratoplasty have changed over the past several years. Nine hundred ninety-nine penetrating keratoplasty specimens from 1981 through 1990 were analyzed. Overall, keratoconus was the most common indication for penetrating keratoplasty (24.2%). This was followed by pseudophakic bullous keratopathy (23.0%), regraft (13.1%), scarring (8.2%), and Fuchs' endothelial dystrophy (5.8%). Pseudophakic bullous keratopathy was the most common indication for penetrating keratoplasty in each year from 1984 through 1989 with a peak in 1987 (33%). Since 1987, the number of pseudophakic bullous keratopathy cases has decreased; and in 1990, keratoconus (33.1%) surpassed pseudophakic bullous keratopathy (24.1%) as the most common indication for penetrating keratoplasty. This decreasing incidence of pseudophakic bullous keratopathy may reflect the discontinued use of closed-looped anterior chamber and iris-plane intraocular lenses most commonly associated with this complication.

Cataract Extraction↗
PubMed1992

Postoperative inflammation following cataract extraction caused by bacterial contamination of the cleaning bath detergent.

Five of 16 patients who had uncomplicated cataract extraction with intraocular lens (IOL) implantation within a 2.5 day period experienced increased anterior segment inflammation on their first postoperative day. Four of these five patients had phacoemulsification and one a planned extracapsular cataract extraction. All had posterior chamber IOL implantation in the capsular bag. In all patients, this anterior segment inflammation cleared with topical steroids over two to three weeks with no evident residual ocular effects. A careful search for the possible cause of the inflammation showed that the ultrasonic cleaning bath and Weck liquid detergent used to clean the instruments contained Klebsiella pneumoniae bacteria. Further investigation demonstrated the presence of a heat-stable endotoxin produced by the bacteria. We postulate that endotoxin remaining on the instruments after cleaning and sterilization caused this postoperative anterior segment inflammation. To the best of our knowledge, these are the first reported cases caused by contaminated liquid detergent.

Aged↗
PubMed1992

Toxic anterior segment inflammation following cataract surgery.

Cataract extraction with posterior chamber intraocular lens implantation is rarely complicated by an acute, sterile, anterior segment inflammation. We report three unrelated cases of acute intraocular inflammation following uncomplicated cataract extraction and posterior chamber intraocular lens placement. A constellation of clinical features were found in these cases. The hallmark of this entity was an acute toxic inflammatory reaction occurring in the anterior segment on the first postoperative day. Typically, widespread corneal edema with diffuse corneal endothelial damage occurred, accompanied by a fixed, dilated pupil with significant iris atrophy and sometimes a severe secondary glaucoma. Since all cultures were negative, the resulting inflammatory processes were not a result of endophthalmitis. We believe that a toxic insult introduced into the anterior chamber at the time of surgery precipitated the acute inflammatory processes seen in these cases.

Aged↗
PubMed1992

Concurrent benign teratoid medulloepithelioma and pineoblastoma.

Teratoid medulloepithelioma of the ciliary body is a rare tumor usually occurring in young children. Primary tumors of the pineal gland are also quite rare and have a similar age distribution. We report the case of a 2-year-old girl who had a leukocoria of the right eye. Cataract surgery was performed; however, the patient developed a total retinal detachment refractory to treatment. She eventually developed early changes of phthisis bulbi and underwent an evisceration. Histopathologic examination revealed a benign teratoid medulloepithelioma containing islands of hyaline cartilage and rhabdomyoblasts. During the course of her evaluation, a pineoblastoma was discovered and surgically excised. While the association of pineal tumors with retinoblastomas has been well established, no such association has been reported for medulloepitheliomas. To our knowledge, this is the first recorded case of a benign teratoid medulloepithelioma occurring concurrently with a pineoblastoma.

Brain Neoplasms↗
PubMed1992

Endothelial cell loss following "modern" phacoemulsification by a senior resident.

Historically, extracapsular cataract extraction (ECCE) has been shown to cause less endothelial cell loss than phacoemulsification. To further evaluate endothelial cell loss following phacoemulsification, we prospectively studied 60 patients who underwent cataract extraction with "in situ" phacoemulsification within the capsular bag following a continuous-tear circular capsulotomy, with placement of a posterior chamber intraocular lens (PC-IOL) in the capsular bag. All procedures were performed by a single senior ophthalmology resident. The average preoperative endothelial count was 2318 +/- 36 cells/mm2; the average postoperative count (at 8.5 weeks) was 2167 +/- 41 cells/mm2. The average endothelial cell loss, then, was 6.4 +/- 1.2%. This level of cell loss with a capsular-bag-fixed PC-IOL is comparable to that reported for ECCE.

Aged↗
PubMed1992

Congenital anomalies of the optic nerve in one family.

We present three cases of congenital optic disc anomalies in one family who underwent an extensive diagnostic workup to exclude any intracranial pathology. One patient had elevated optic nerve heads and was hospitalized for multiple diagnostic tests including a lumbar puncture and magnetic resonance imaging scan. This patient had a sister with a previous history of having undergone head and orbital computed tomography to evaluate her symptoms of headaches with anomalous optic nerve heads. The third patient was the father of the other two patients who had previously undergone an extensive evaluation for elevated optic nerve heads and was treated for presumed pseudotumor cerebri with fenestration of the optic nerve sheath. These cases underscore the importance of a detailed family history and examination of family members to exclude congenital abnormalities of the optic nerve head before beginning an extensive workup.

Adolescent↗
PubMed1991

Clinical comparison of ocular irrigation fluids following chemical injury.

This study tested the hypothesis that four ocular irrigating solutions were equally irritating during copious irrigation. We conducted a prospective, double-blind study of patients with chemical exposure to the eye. Each underwent cross-over irrigation with all of the following in random order: normal saline (NS), lactated Ringer's (LR), normal saline adjusted to pH 7.4 with sodium bicarbonate (NS + Bicarb), and Balanced Saline Solution Plus (BSS Plus, Alcon Laboratories, Fort Worth, TX). Compared with traditional NS and LR, NS + Bicarb tended to be more comfortable. BSS Plus was statistically superior (P less than .05) to NS and preferred over LR and NS + Bicarb. Three patients demanded discontinuance of NS or NS + Bicarb infusions. All solutions had comparable normalization of conjunctival pH and degree of injection. Alternate solutions including BSS Plus should be considered for use in those patients whose poor tolerance to normal saline threatens to delay or interrupt eye irrigation following a chemical injury.

Bicarbonates↗
PubMed1991

Penetrating keratoplasty 1981-1988: clinical indications and pathologic findings.

We analyzed 740 penetrating keratoplasty specimens received at the Intermountain Ocular Research Center from 1981 through 1988. These corneal specimens were categorized by clinical indications for removal and pathologic confirmation of the clinical findings. Keratoconus was the most common indication for a penetrating keratoplasty (22.8%). This was closely followed by pseudophakie bullous keratopathy (21.8%), regraft (13.2%), scarring (8.9%), aphakic bullous keratopathy (6.4%), and Fuchs' endothelial dystrophy (5.8%). Since 1984, pseudophakic bullous keratopathy has surpassed keratoconus as the most common indication for penetrating keratoplasty (27.3% vs. 20.2%). Pseudophakic bullous keratopathy was found more commonly than keratoconus in each of the last four years of this study. The most common type of intraocular lens associated with pseudophakic bullous keratopathy was an anterior chamber lens (52.8%), with iris-fixated (26.7%) and posterior chamber (17.4%) lenses seen less frequently.

Adolescent↗
PubMed1991

Intraocular lens explantation and exchange. A review of lens styles, clinical indications, clinical results, and visual outcome.

We conducted a retrospective review of 102 patients who had intraocular lens (IOL) explantation or exchange over a 7.5 year period. Seventy-one patients had IOL exchange while 31 had lens removal without exchange. Anterior chamber IOLs comprised 66.7% of the lenses removed. The most frequent indication for anterior chamber IOL explantation was pseudophakic bullous keratopathy (PBK), followed by the uveitis-glaucoma-hyphema syndrome and cystoid macular edema. Of the IOLs removed, 17.6% were iris-supported, with PBK being the most common indication for removal. Posterior chamber IOLs comprised 15.7% of the explanted lenses in this series. Lens dislocation/decentration was the leading indication for IOL removal in the posterior chamber IOL group. Among the 71 patients who had IOL exchange, 71.8% received an anterior chamber lens and 28.2% received a posterior chamber lens. Visual outcome following IOL exchange or removal showed that 40 patients (39%) improved, 47 patients (46%) had the same vision, and 15 patients (15%) had worse vision postoperatively. The most common reason for a worsening of vision postoperatively was corneal decompensation, followed by glaucoma and cystoid macular edema. Analysis of the clinical results revealed that 86.3% of the patients who had an exchange with an anterior chamber IOL had a successful outcome with either improvement or stabilization of the ocular condition. Ninety percent of the patients who received a posterior chamber IOL had a successful clinical outcome.

Anterior Chamber↗
PubMed1991

Protective effects of Healon and Occucoat against air bubble endothelial damage during ultrasonic agitation of the anterior chamber.

An important aspect of any new viscoelastic substance is the corneal endothelial protection. We compared the protective effects of sodium hyaluronate (Healon) and hydroxypropylmethylcellulose (Occucoat) by introducing a controlled volume of air bubbles into the anterior chamber of human eye bank eyes during ultrasonic agitation of the anterior chamber. Eight eyes received Healon and 11 eyes received Occucoat. Damage to endothelial cells in the central cornea was quantified by vital staining. Endothelial damage averaged 4.5% in eyes in which no viscoelastic was used (positive control); damage was 0.4% in eyes in which a viscoelastic was injected but no air bubbles were introduced (negative control). We found that endothelial damage averaged 4.25% in specimens that received air plus Healon and 1.4% in specimens that received air plus Occucoat. Occucoat appeared to have somewhat better protective effects than Healon against air bubble damage to the corneal endothelium during ultrasonic agitation of the anterior chamber.

Air↗
PubMed1991

Optical differences in multiple personality disorder. A second look.

The study was designed as a replication of a study reported in this Journal (Miller S [1989] Optical differences in cases of multiple personality disorder. J. Nerv Ment Dis 177:480-486) which found that subjects with multiple personality disorder (MPD) experienced significantly more changes in visual functioning between alter personalities than a control group simulating the disorder. In the present study, data from 20 patients diagnosed with MPD and 20 control subjects role playing MPD were analyzed for statistical and clinical significance. The findings from the present study appear to confirm results from the earlier study that individuals with MPD experience differences in some aspects of visual functioning between alter personalities. The results further confirm that MPD subjects experience more differences across visual measures than control subjects simulating the disorder. However, the findings from the present study are not entirely consistent across the various visual measures or with findings from previous studies.

Adult↗