Biomedical subjects

J M Liebmann

Publications and source records attributed to J M Liebmann.

At least 19 recordsLinked to original sources

PubMed1999

Iridolenticular contact decreases following laser iridotomy for pigment dispersion syndrome.

OBJECTIVE: To evaluate changes in anterior segment anatomy after laser iridotomy for pigment dispersion syndrome. METHODS: Ultrasound biomicroscopy was performed on 7 eyes of 7 untreated patients with reverse pupillary block and pigment dispersion syndrome. A radially oriented image with the probe perpendicular to the eye in the superior meridian was obtained before and at least 1 week after laser iridotomy in each eye. We assessed changes in angle recess area and iris-lens contact distance. RESULTS: Mean +/- SD patient age was 31.3 +/- 5.7 years and mean +/- SD refractive error was -5.0 +/- 3.9 diopters. Angle recess area (mean +/- SD, 0.78 +/- 0.28 vs 0.35 +/- 0.11 mm2; P=.001, paired t test) and iris-lens contact distance (2.05 +/- 0.28 vs 0.79 +/- 0.13 mm; P<.001) decreased following iridotomy. Central anterior chamber depth did not change. CONCLUSION: Flattening of the iris following laser iridotomy for pigment dispersion syndrome causes a decrease in iris-lens contact and angle width while lens position remains constant.

Adult↗

PubMed1999

Aqueous misdirection after glaucoma drainage device implantation.

OBJECTIVE: To describe the clinical presentation, outcome, and possible underlying mechanism of aqueous misdirection after glaucoma drainage device implantation. DESIGN: Retrospective, noncomparative, interventional case series. PARTICIPANTS: Ten eyes (five primary open-angle glaucoma, four chronic angle-closure glaucoma, one nanophthalmos) of nine patients with a mean age of 68.5+/-12.0 years (range, 43-83 years). INTERVENTION: The authors reviewed the medical records of all patients with a clinical diagnosis of aqueous misdirection after Baerveldt glaucoma drainage device implantation at two tertiary care referral centers from October 1992 to October 1997. Surgery was performed in a standardized fashion; all drainage tubes were inserted in the anterior chamber and occluded with an external 7-0 polyglactin ligature. All eyes were treated with topical corticosteroids, cycloplegia, and aqueous suppressants. Eyes with persistent aqueous misdirection received neodymium:YAG (Nd:YAG) hyaloidotomy or pars plana vitrectomy. MAIN OUTCOME MEASURES: Visual acuity, intraocular pressure, biomicroscopic anterior chamber depth, and antiglaucomatous medication. RESULTS: All eyes had axial shallowing of the anterior chamber, one or more patent iridotomies, and no ophthalmoscopic or B-scan ultrasonographic evidence of serous or hemorrhagic ciliochoroidal detachment. Median time to the development of angle-closure glaucoma was 33.5 days (range, 1-343 days) and mean intraocular pressure at diagnosis was 27.7+/-18.7 mm Hg (range, 10-62 mm Hg). Normalization of anterior segment anatomy was achieved with aqueous suppression and cycloplegia (one eye); Nd:YAG capsulotomy (four eyes); pars plana vitrectomy alone (two eyes) or with lensectomy (one eye), and pars plana vitrectomy with intraocular lens explanation (two eyes). Mean final intraocular pressure was 14.1+/-6.0 mmHg at a mean follow-up of 9.1+/-7.8 months after the development of aqueous misdirection (range, 1-23 months). CONCLUSIONS: Aqueous misdirection may develop days to months after glaucoma drainage device implantation. In this series, there was a poor response to medical therapy, and normalization in anterior chamber depth required aggressive laser and surgical therapy.

Adult↗

PubMed1999

Prolonged suppression of human immunodeficiency virus type 1 (HIV-1) viremia in persons with advanced disease results in enhancement of CD4 T cell reactivity to microbial antigens but not to HIV-1 antigens.

CD4 T cell responses were studied for >2 years in 27 zidovudine-experienced patients with advanced human immunodeficiency virus type 1 (HIV-1) infection who received triple combination drug therapy with indinavir, zidovudine and lamivudine or zidovudine plus lamivudine or zidovudine alone for 24-42 weeks before switching to the three-drug therapy. Subjects initially given the three drugs had viremia suppressed to undetectable levels and increases in T cell proliferative and cytokine responses to microbial antigens through 2 years of follow-up. Patients receiving the triple-drug therapy after either indinavir or zidovudine-lamivudine treatment had similar increases in T cell responses only if they also had suppression of virus load. CD4 T cell reactivity to HIV-1 antigens was not restored. Prolonged indinavir-zidovudine-lamivudine treatment has significant but incomplete enhancing effects on CD4 T cell reactivity, which could be important in host control of microbial and persistent HIV-1 infections.

Acquired Immunodeficiency Syndrome↗

PubMed1999

Analysis of myocilin mutations in 1703 glaucoma patients from five different populations.

A glaucoma locus, GLC1A, was identified previously on chromosome 1q. A gene within this locus (encoding the protein myocilin) subsequently was shown to harbor mutations in 2-4% of primary open angle glaucoma patients. A total of 1703 patients was screened from five different populations representing three racial groups. There were 1284 patients from primarily Caucasian populations in Iowa (727), Australia (390) and Canada (167). A group of 312 African American patients was from New York City and 107 Asian patients from Japan. Overall, 61 different myocilin sequence variations were identified. Of the 61 variations, 21 were judged to be probable disease-causing mutations. The number of probands found to harbor such mutations in each population was: Iowa 31/727 (4.3%), African Americans from New York City 8/312 (2.6%), Japan 3/107 (2.8%), Canada 5/167 (3.0%), Australia 11/390 (2.8%) and overall 58/1703 (3. 4%). Overall, 16 (76%) of 21 mutations were found in only one population. The most common mutation observed, Gln368Stop, was found in 27/1703 (1.6%) glaucoma probands and was found at least once in all groups except the Japanese. Studies of genetic markers flanking the myocilin gene suggest that most cases of the Gln368Stop mutations are descended from a common founder. Although the specific mutations found in each of the five populations were different, the overall frequency of myocilin mutations was similar ( approximately 2-4%) in all populations, suggesting that the increased rate of glaucoma in African Americans is not due to a higher prevalence of myocilin mutations.

Asian People↗

PubMed1999

A slit-lamp needling filtration procedure for uncontrolled glaucoma in pseudophakic and aphakic eyes.

In one aphakic and one pseudophakic patient without previous filtration surgery, a transconjunctival needling procedure similar to that used for failed filtration procedures was performed to create a filtering bleb. In both cases, intraocular pressure was successfully lowered for 6 months until the occurrence of bleb encapsulation, which was relieved by transconjunctival needling. There were no complications. In selected cases, this minimally invasive slit-lamp needling procedure provides successful filtration.

Aged↗

PubMed1999

A slit-lamp eyepiece micrometer calibrated at 50-micron intervals.

Measurements of dimensions of various intraocular structures, both normal and abnormal, are both theoretically and clinically useful. The currently available standard Haag-Streit slit-lamp micrometer eyepiece is calibrated at 100 micron intervals. In order to achieve greater precision in measurement of smaller intraocular structures, the authors and Haag-Streit, Inc. (Kaniz, Switzerland) have developed an eyepiece calibrated in 50-micron intervals.

Calibration↗

PubMed1998

Anterior segment implantation cysts. Ultrasound biomicroscopy with histopathologic correlation.

OBJECTIVE: To correlate the clinical, histopathologic, and ultrasound biomicroscopic characteristics of anterior segment implantation cysts. METHODS: We performed a retrospective review of 7 cases of secondary anterior segment implantation cysts. We reviewed the clinical history, visual acuity, clinical findings, and ultrasound biomicroscopic characteristics in all cases. Histopathologic correlation was possible in 4 cases. RESULTS: Six eyes had been subjected to major trauma prior to cyst formation. Trauma was noted as blunt in 3 eyes and surgical in 3 eyes. The diagnosis was confirmed in 1 eye when conjunctival cells were aspirated on fine needle biopsy. Ultrasound biomicroscopy revealed large (mean +/- SD greatest diameter, 4.7 +/- 0.9 mm) cystic tumors. In 1 patient, a cyst-related indentation of the anterior lens surface was seen. Ultrasonographic evaluations of internal reflectivity revealed thick, moderately reflective cyst walls encapsulating a relatively hypoechoic core. In 3 cases, the cyst contents consisted of variably reflective material. The other 4 were completely sonolucent. Histopathologic correlation showed that the cyst walls were lined with stratified squamous epithelium. The moderately reflective cyst contents were found to be degenerated conjunctival cells with inflammatory foci and cholesterol crystals. The sonolucent regions correlated with inflammatory cells and fluid. CONCLUSIONS: This study demonstrates that implantation cysts are unilateral, large, and thick walled. They may be sonolucent or exhibit variable internal reflectivity. These findings as well as the extent of anterior segment involvement (particularly posterior extension) could be evaluated by ultrasound biomicroscopy prior to surgery.

Adolescent↗

PubMed1998

Late-onset bleb leaks after glaucoma filtering surgery.

OBJECTIVE: To determine the incidence of focal, late-onset, conjunctival bleb leaks after glaucoma filtering surgery. DESIGN: Prospective, cross-sectional analysis. SETTING: Tertiary care outpatient referral center. PATIENTS: Consecutive patients who underwent glaucoma filtering surgery prior to June 1996 presenting for evaluation from September 2,1996, through November 15,1996. Five hundred twenty-five eyes of 525 consecutive patients were enrolled in the study. INTERVENTION: Bleb height (elevated or flat), area (diffuse or localized), and wall thickness (thin, thick, or encapsulated) were classified. Each bleb was tested for focal leakage using a moistened fluorescein strip, cobalt blue illumination, and slit-lamp biomicroscopy. Diffuse transconjunctival aqueous flow did not qualify as a focal leak. MAIN OUTCOME MEASURE: Seidel-positive aqueous leakage. RESULTS: Bleb leakage occurred in 14 eyes following trabeculectomy (mitomycin C treatment, 10 eyes; 5-fluorouracil treatment, 3 eyes; no antifibrosis agent, 1 eye) and in 1 eye following combined cataract and glaucoma surgery with adjunctive mitomycin C therapy. Bleb leakage occurred more frequently in eyes that received mitomycin C (10 [3.7%] of 273 eyes) than 5-fluorouracil (3 [1.4%] of 213 eyes) or no antifibrosis agent (1 [2.6%] of 39 eyes), using Kaplan-Meier estimates (P=.008, log-rank test). Conjunctival blebs were significantly thinner after trabeculectomy with mitomycin C than with 5-fluorouracil (P=.001). Bleb wall thickness was greater following combined cataract and glaucoma surgery than following trabeculectomy alone (P=.008). Age (P=.84), sex (P=.68), race (P=.77), duration of mitomycin C exposure (P=.62), number of antiglaucoma medications (P=.16), and total 5-fluorouracil dose (P=.85) were not associated with late-onset leaks. CONCLUSIONS: The risk of late-onset focal bleb leakage increases following trabeculectomy with mitomycin C therapy. Late leakage after combined cataract and glaucoma surgery is infrequent.

Adolescent↗

PubMed1998

Angle-closure glaucoma associated with occult annular ciliary body detachment.

OBJECTIVE: To evaluate the role of annular ciliary body detachment in the development of postoperative angle-closure glaucoma. DESIGN: Case series. SETTING: Tertiary care glaucoma referral center. METHODS: High-resolution, anterior segment ultrasound biomicroscopy, ophthalmoscopy, and B-scan ultrasonography were performed on 6 eyes of 6 patients with a clinical diagnosis of postoperative malignant glaucoma. RESULTS: Each eye had an elevated intraocular pressure, a shallow anterior chamber, 1 or more patent iridectomies, and no ophthalmoscopic or B-scan ultrasound evidence of serous or hemorrhagic ciliochoroidal detachment. Ultrasound biomicroscopy revealed annular ciliary body detachment in each eye. In 4 eyes, observation with topical medical treatment was associated with deepening of the anterior chamber, reduced intraocular pressure, and resolution of the detachment. Drainage of the supraciliary fluid was performed in 2 eyes. CONCLUSION: Occult, annular, serous detachment of the ciliary body may cause postoperative angle-closure glaucoma. This entity is clinically indistinguishable from malignant glaucoma. Ultrasound biomicroscopy facilitates the diagnosis.

Aged↗

PubMed1998

Ultrasound biomicroscopic localization and evaluation of intraocular foreign bodies.

PURPOSE: To evaluate the ultrasound biomicroscopic appearance of anterior segment foreign bodies under clinical and experimental conditions. METHODS: Ultrasound biomicroscopy was performed on 4 eyes of 4 patients referred for evaluation of anterior segment trauma and known or suspected intraocular foreign body. Imaging of wood, aluminum, concrete, and glass foreign bodies was performed in the anterior chamber of a human cadaver eye. RESULTS: Ultrasound biomicroscopy verified the location of a foreign body in two patients and identified occult foreign bodies in two others. Under clinical and experimental conditions, intraocular aluminum and glass produced comet tail artifacts. Under experimental conditions intraocular wood and concrete produced shadowing artifacts. CONCLUSION: Ultrasound biomicroscopy provides useful information in the evaluation of known and occult anterior segment foreign bodies. Ultrasound patterns of shadowing and comet tail may help differentiate foreign body materials.

Adolescent↗

PubMed1998

Lack of cross-reactive allergic response to brimonidine in patients with known apraclonidine allergy.

PURPOSE: To assess the allergenic potential of topical brimonidine 0.2% in patients shown to be allergic to apraclonidine 0.5%. METHODS: Eighteen glaucoma patients who developed allergy to apraclonidine were enrolled. Allergy was graded and documented photographically. Apraclonidine was then discontinued until the allergy resolved. Grading and photography were repeated, following which treatment with brimonidine was initiated. Patients were examined 1 h after the initial drop of brimonidine, twice weekly for 6 weeks, and at 3 monthly intervals thereafter. All other anti-glaucoma medications were continued. RESULTS: Mean patient age was 66.3 +/- 14.9 years (range 33.5-89.3 years). The mean time to apraclonidine allergy from initial exposure was 12.9 +/- 12.9 months (range 2.1-46.8 months). For the 10 patients rechallenged with apraclonidine, the mean time to allergy was 13.6 +/- 10.2 days (range 3-32 days). Mean duration of brimonidine therapy was 140.7 +/- 66.2 days (range 14-286 days), with 11 patients reaching at least 150 days of follow-up. Two patients developed symptomatic brimonidine allergy at 138 and 201 days respectively. For those patients who did not develop symptoms of allergy to brimonidine, there was no significant change in any of the parameters by which allergy was graded throughout the study. CONCLUSIONS: Patients with known apraclonidine allergy do not develop an early allergic response to brimonidine. These data rule against a cross-reactive allergic response between these two alpha 2-adrenoreceptor agonists.

Adrenergic alpha-Agonists↗

PubMed1998

New patterns of infecting organisms in late bleb-related endophthalmitis: a ten year review.

PURPOSE: To report the risk factors, causative organisms and visual outcomes in patients with late-onset bleb-related endophthalmitis. METHODS: Medical records of all patients with the clinical diagnosis of late-onset bleb-related endophthalmitis undergoing vitreous aspirates for culture at our institution from January 1987 to July 1996 were reviewed. Late-onset bleb-related endophthalmitis was defined as conjunctival injection, bleb purulence and intraocular inflammation developing at least 1 month following filtering surgery. RESULTS: Forty-nine cases of bleb-related endophthalmitis developed in 42 patients (23 men, 19 women). Mean patient age was 62.1 +/- 19.3 years (range 5-94 years). Thirty-nine patients underwent prior filtering surgery (superior trabeculectomy, 24 eyes; inferior trabeculectomy, 10 eyes; combined superior trabeculectomy/cataract extraction, 4 eyes; posterior lip sclerectomy, 1 eye) and 3 had inadvertent blebs following cataract extraction. Endophthalmitis developed an average of 25.4 +/- 23.5 months (range 1-96 months) post-operatively. Antifibrosis agents were used in 25 of 39 eyes undergoing filtering surgery (mitomycin C, 13 eyes; 5-fluorouracil, 12 eyes). Bleb leaks were documented in a total of 32 of 49 (65%) cases either before or at the time of endophthalmitis diagnosis. Vitreous cultures were positive in 42 of 49 (86%) cases. The most frequently cultured organisms were Staphylococcus aureus (13), Staphylococcus epidermidis (12), Streptococcus species (8) and Haemophilus influenzae (2). A final visual acuity of 20/400 or better was achieved in 32 of 49 (65%) cases. CONCLUSIONS: Staphylococcal species were the most frequently cultured organisms in this series and may be associated with better visual outcomes. Although a causal relationship cannot be established, these results suggest a strong association between bleb leaks and endophthalmitis.

Adolescent↗

PubMed1998

Role of ultrasound biomicroscopy in the differentiation of block glaucomas.

Ultrasound biomicroscopy has allowed us to elucidate the anatomic variations and underlying mechanisms in angle-closure glaucoma. Four levels of anatomic block can be distinguished, and a specific approach to treatment exists for each level to correct the abnormal forces leading to closure of the angle. As more quantitative approaches are developed, our understanding of these disorders will become increasingly sophisticated.

Anterior Eye Segment↗

PubMed1998

Recurrent bleb infections.

AIM: To report the patient characteristics, causative organisms, and clinical outcomes in patients with recurrent bleb related ocular infections. METHODS: The medical records of all patients diagnosed with bleb related ocular infection at the New York Eye and Ear Infirmary over a 10 year period were reviewed. Recurrent bleb infection was defined as at least two episodes of bleb purulence with or without associated intraocular inflammation separated by a quiescent period of at least 3 months. RESULTS: Recurrent bleb infections developed in 12 eyes of 12 patients (10 men, two women) a mean of 16.3 (SD 17.9) months (range 3-51 months) after the initial infection. Two patients developed a third episode 3 and 20 months, respectively, after the second infection, yielding a total of 14 recurrent infection episodes. Recurrent infection developed after trabeculectomy in 11 eyes (adjunctive 5-fluorouracil, nine eyes; mitomycin C, one eye; no antifibrosis agent, one eye) and following cataract extraction with inadvertent bleb formation in one eye. Four (36.4%) of the filtered eyes had undergone trabeculectomy at the inferior limbus. The mean follow up time from filtering surgery to the first bleb related infection was 28 months for the nine patients treated with 5-fluorouracil and 14 months for the single patient treated with mitomycin C. 11 (78.6%) cases had a documented bleb leak in the 4 week period before or at the time of recurrent infection. Topical, prophylactic antibiotics had been used in 7/14 (50%) cases. The same organism was cultured from the initial and recurrent infections in 2/14 (14.3%) cases. CONCLUSION: Eyes that have been successfully treated for bleb related infection remain at risk for recurrent infection. No apparent correlation exists between organisms responsible for the initial and recurrent infections. The increased rate of recurrent bleb related infection in patients receiving adjunctive 5-fluorouracil compared to mitomycin C may have been related to the longer follow up of the 5-fluorouracil eyes.

Adult↗

PubMed1998

Peripapillary nerve fiber layer thickness measurement reproducibility using scanning laser polarimetry.

PURPOSE: The authors assess the reproducibility of retinal nerve fiber layer (RNFL) thickness measurements using scanning laser polarimetry. METHODS: The right eyes of five healthy individuals were scanned by two trained operators (S.T.H., H.I.) using the Nerve Fiber Analyzer II (Laser Diagnostic Technologies, Inc., San Diego, CA, U.S.A.). Each participant was scanned six consecutive times per session for five sessions carried out over separate days within a two-week period. Intra- and interoperator measurement reproducibility was assessed. RESULTS: Intraoperator reproducibility was high. Mean coefficients of variation for total RNFL thickness measurements were 4.48 +/- 1.76% and 4.92 +/- 2.32% for operators 1 and 2, respectively. Interoperator reproducibility was high (p = 0.20-0.93) if a single ellipse was applied to the images of both examiners. However, measurement reproducibility worsened if each operator created his own measurement ellipse (p < or = 0.05 for 3 out of 5 participants). CONCLUSION: Interoperator error in image analysis can be minimized by using a single ellipse for the baseline and all subsequent scans even if subsequent scans are acquired by different operators.

Adult↗

PubMed1998

Pericardial patch grafts in glaucoma implant surgery.

PURPOSE: The authors determine the safety and effectiveness of pericardial patch grafts in glaucoma implant surgery. METHODS: A retrospective chart review was conducted on all patients who underwent a glaucoma implant procedure with the use of a pericardial patch graft to cover the subconjunctival portion of the tube at The New York Eye and Ear Infirmary between September 1, 1995 and June 30, 1996. Charts were assessed for evidence of delle formation, graft rejection, graft-related infection, graft thinning, or tube erosion. RESULTS: Forty-four eyes of 44 patients were enrolled. Mean follow-up was 10.2 +/- 4.0 months (range, 2.3 to 18.6 months). Infection, tube erosion, graft rejection, and graft-related inflammation did not occur. Five eyes were noted to have asymptomatic thinning of the patch without evidence of tube erosion. CONCLUSIONS: Preserved human cadaveric pericardial patch grafts appear to be well-tolerated for use with glaucoma drainage devices. As with other grafting material, potential for graft thinning is possible and further long-term experience is needed.

Adolescent↗

PubMed1998

Late hypotony after cataract extraction due to a scleral fistula: a technique for surgical correction.

The authors report the use of a surgical procedure for the correction of a scleral fistula in a patient with late hypotony after cataract surgery. Trephination of necrotic tissue lining the scleral fistula with a double scleral patch technique was performed. Four months later, the patient's vision had improved to 20/40, with improvement of the macular folds and an intraocular pressure of 10 mm Hg. The authors conclude that the use of a double-patching technique is effective in the repair of scleral fistulas. The technique allows one to avoid more risky repair procedures that involve a greater area of tissue excision.

Aged↗

PubMed1998

Reproducibility of retinal thickness measurements in normal eyes using optical coherence tomography.

BACKGROUND AND OBJECTIVE: To determine the reproducibility of retinal thickness measurements in normal eyes using optical coherence tomography (OCT). PATIENTS AND METHODS: Multiple 3.20-mm vertical cross-sectional images through the center of fixation of consecutive patients with normal results on ocular examinations were obtained. Each image was divided into seven 320-micron segments. Regional retinal thicknesses for each section were measured using both the manually assisted (requiring observer localization of reflectivity peaks) and the automated modes (observer-independent measurement) of the computer software. RESULTS: Eighteen right eyes were studied. The mean coefficient of variation was less than 10% for all locations using the manually assisted method (average standard deviation less than 17 microns [range 9 to 16 microns]). The automated method was less reliable, with a coefficient of variation greater than 10% for locations within 500 microns of fixation. Automated measurements at fixation were the least reproducible because of poor internal limiting membrane reflectivity. CONCLUSION: OCT is capable of reproducible measurement of retinal thickness in normal eyes. Computer-driven, automated measurement of retinal thickness within 500 microns of fixation needs to be refined and its reproducibility reassessed in this region.

Adult↗