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Jeffrey M Liebmann

Publications and source records attributed to Jeffrey M Liebmann.

53 records · Page 3Linked to original sources
PubMed2003

Multifocal visual evoked potential responses in glaucoma patients with unilateral hemifield defects.

PURPOSE: To determine whether the multifocal visual evoked potential (mfVEP) technique can detect damage to the visual system in the unaffected hemifields of patients with glaucoma and unilateral hemifield defects. DESIGN: Experimental study. METHODS: Monocular mfVEPs and achromatic automated perimetry (AAP) were obtained in both eyes of 16 patients with open-angle glaucoma and unilateral hemifield defects. The mfVEPs were obtained using a pattern-reversal dartboard array with 60 sectors; the entire display was 44.5 degrees in diameter. For each pair of mfVEP responses an interocular ratio of root-mean-square amplitude was calculated. These values were compared with the mean values obtained from 30 control subjects. Probability plots for MfVEP were derived. A cluster analysis was used to determine whether an mfVEP hemifield was normal or abnormal. RESULTS: Three of 60 (5.0%) mfVEP hemifields from control subjects had significant mfVEP deficits based upon a cluster of abnormal points. Significant mfVEP deficits were detected in the affected AAP hemifield in 15 of 16 (93.8%) glaucoma patients and in 6 of 16 patients in hemifields with apparently normal AAP. The percentage of hemifields with abnormal mfVEPs, but normal AAP, was significantly higher for the glaucoma patients than for the controls (37.5% vs 5.0%, P <.001, chi square).In glaucomatous eyes with achromatic visual fields defects limited to one hemifield, the mfVEP technique can detect evidence of glaucomatous damage in the unaffected hemifield.

Adult↗
PubMed2003

Angle closure in younger patients.

PURPOSE: Angle-closure glaucoma is rare in children and young adults; only scattered cases associated with specific clinical entities have been reported. We evaluated the findings in patients aged 40 or younger with angle closure in our database. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: Our database was searched for patients aged 40 years or younger with angle closure. Data recorded included age at initial consultation, age at the time of diagnosis, gender, slit-lamp examination, gonioscopy, ultrasound biomicroscopy (from 1993 onward), clinical diagnosis, and therapy. Patients with prior incisional surgery were excluded, as were patients with anterior chamber proliferative mechanisms leading to angle closure. RESULTS: Sixty-seven patients (49 females, 18 males) met entry criteria. Mean age at the time of consultation was 34.4 +/- 9.4 (standard deviation) years (range, 3-68 years). Diagnoses included plateau iris syndrome (35 patients); iridociliary cysts (8 patients); retinopathy of prematurity (7 patients); uveitis (5 patients); isolated nanophthalmos (3 patients); relative pupillary block (2 patients); Weill-Marchesani syndrome (3 patients); and 1 patient each with Marfan syndrome, miotic-induced angle closure, persistent hyperplastic primary vitreous, and idiopathic lens subluxation. CONCLUSIONS: The etiology of angle closure in young individuals differs from the older population and is typically associated with structural/developmental ocular anomalies rather than relative pupillary block. After laser iridotomy, these eyes should be monitored for recurrent angle closure and the need for additional laser or incisional surgical intervention.

Adolescent↗
PubMed2003

Repeat reliability of the multifocal visual evoked potential in normal and glaucomatous eyes.

PURPOSE: To investigate the repeat reliability of the multifocal visual evoked potential (mfVEP). PATIENTS AND METHODS: Fifteen subjects with no known abnormalities of the visual system and 10 patients with glaucoma participated in the study. Monocular mfVEPs were recorded on two separate days, using a 60-sector, pattern-reversal dart board array. Within a single session, two 7-minute. recordings were obtained for each eye. The amplitude of each mfVEP response was obtained using a root mean square measure (RMS). An mfVEP ratio [10*log (RMS day 1 / RMS day 2)] provided a measure of the reproducibility of an individual response. The same calculations were performed for Run 1 compared with Run 2 within a day and Run 1 (Run 2) compared with Run 1 (Run 2) across days. RESULTS: For all 1800 mfVEP responses (60 sectors x 15 subjects x 2 eyes), the correlation between the amplitude on day 2 and the amplitude on day 1 was good (r = 0.85). The mean standard deviation (SD) of the 60 mfVEP ratios for the individual subjects was 1.63 dB for the 14-minute records (the combination of the two 7-minute recordings). On average for the 7-minute records, the mean SD across days was 1.77 dB while the mean SD within a day was 1.53 dB. The correlation within a day (r = 0.87) also was slightly larger than across days (r = 0.80). The mean SD decreased as the RMS amplitude increased. The patients' mean SD was 1.75 dB with r equal to 0.82. CONCLUSIONS: The repeat reliability of the mfVEP was good (approximately 1.6dB); in fact, it was better than that typically obtained with static automated perimetry (approximately 2.7dB). Repeat testing on separate days added surprisingly little to the variability seen with repeat testing within the same session.

Adolescent↗
PubMed2002

Detecting the inner and outer borders of the retinal nerve fiber layer using optical coherence tomography.

BACKGROUND: The purpose of this study was to develop a new algorithm to detect the inner and outer borders of the retinal nerve fiber layer (RNFL) using optical coherence tomography (OCT). METHODS: A program featuring a new algorithm was developed using a commercially available software development environment. The algorithm searches for peaks on each sampling line instead of applying conventional thresholding techniques. All circular peripapillary OCT images obtained at the New York Eye and Ear Infirmary from October 1996 to December 2000 were analyzed using the new and the commercially available algorithms. RESULTS: Four hundred one images of 98 patients were analyzed. The detection error rate (defined as number of scans with five consecutive sampling lines with disrupted RNFL borders) was significantly lower with the new algorithm (25/401 images, 6.2%) than with the commercially available algorithm (70/401 images, 17.5%) (P=0.018, chi-square). CONCLUSION: The new algorithm improved the ability of OCT to detect the borders of the RNFL.

Adult↗
PubMed2002

Visual field defects and multifocal visual evoked potentials: evidence of a linear relationship.

OBJECTIVE: To determine the relationship between spatially localized multifocal visual evoked potentials (mfVEPs) and Humphrey visual fields (HVFs) in patients with unilateral field defects. METHODS: Humphrey visual fields and mfVEPs were obtained from 20 patients with unilateral field losses due to either ischemic optic neuropathy or glaucoma. Monocular mfVEPs were obtained for each eye. The amplitude of the mfVEP responses was calculated using root-mean-square and signal-noise ratio measures. Estimates of the HVF loss in the same regions of the field used for the mfVEP were obtained by interpolating the 24-2 HVF data. RESULTS: Monocular mfVEP amplitude decreased with HVF loss, although small mfVEP signals were not uniquely associated with poor fields. On average, the monocular mfVEP was indistinguishable from noise for field losses between -5 and -10 dB, and good monocular mfVEP amplitudes were never associated with extensive visual field loss. The interocular ratio of the mfVEP amplitudes correlated well with the difference between the HVF values of the 2 eyes, and this correlation improved with increased signal-noise ratio. CONCLUSIONS: The monocular and interocular results were consistent with a linear relationship between the amplitude of the signal portion of the mfVEP response and linear HVF loss. One way to produce this relationship would be if both the signal in the mfVEP and linear HVF loss were linearly related to the percentage of local ganglion cells lost. The clinical limitations of the mfVEP technique can be understood by taking the signal-noise ratio, and the linear model proposed herein, into consideration.

Adult↗
PubMed2002

Ultrasound biomicroscopy in uveitis-glaucoma-hyphema syndrome.

PURPOSE: To assess anterior segment anatomy in uveitis-glaucoma- hyphema syndrome. DESIGN: Retrospective case series. METHODS: Nine pseudophakic eyes (nine patients) with complete or incomplete uveitis-glaucoma-hyphema syndrome underwent ultrasound biomicroscopy. RESULTS: Ultrasound biomicroscopy revealed intraocular lens malposition in each case. Of the eight eyes with posterior chamber intraocular lenses, haptics were in contact with the iris pigment epithelium (four eyes) or the pars plicata (three eyes) or prolapsed into the angle recess near a filtration bleb internal ostium (one eye). All other posterior chamber intraocular lens haptics were located in the ciliary sulcus with the exception of two in the capsular bag. Both haptics in the eye with the anterior chamber intraocular lens had eroded into the ciliary body. CONCLUSION: By its ability to detect haptic position, ultrasound biomicroscopy can assist in elucidating the cause of uveitis-glaucoma-hyphema syndrome and in deciding on the course of treatment.

Aged↗
PubMed2002

Attempted eyelid closure affects intraocular pressure measurement in open-angle glaucoma patients.

PURPOSE: To evaluate the effect of attempted eyelid closure on intraocular pressure (IOP) measurements in normal-tension (NTG) and high-tension (HTG) open-angle glaucoma patients. DESIGN: Prospective clinical trial. METHODS: Forty randomly selected eyes of 40 patients underwent corneal pachymetry and IOP measurements using both Goldmann applanation tonometry and Tono-pen XL (Mentor, Inc., Norwell, Massachusetts, USA). Intraocular pressure was measured by the same examiner holding the eyelids open, both with and without the subject simultaneously attempting forced eyelid closure. Subjects were seated during all measurements and waited 5 minutes between measurements with each instrument; the order of measurement was randomized. RESULTS: Twenty NTG and 20 HTG eyes were enrolled. The mean age was 63.0 +/- 13.0 years (range, 31-80 years). The average corneal thickness was 540 +/- 32 microm (range, 480-608 microm) in NTG patients and 552 +/- 40 microm (range, 449-610 microm) in HTG patients (P =.07, analysis of variance [ANOVA]). Using Goldmann applanation tonometry, IOP measurement in eyes with NTG increased by 3.9 +/- 2.0 mm Hg with attempted eyelid closure (P <.0001, paired t test; range, 2-11 mm Hg). With the Tono-pen XL, IOP measurements increased 4.2 +/- 2.7 mm Hg (P <.0001, paired t test; range, 1-14 mm Hg). With attempted forced eyelid closure, the Goldmann applanation measurement in eyes with HTG increased 4.1 +/- 2.1 mm Hg (P <.0001, paired t test; range, 1-9 mm Hg). Using the Tono-pen XL, measurements increased 4.5 +/- 2.0 mm Hg (P <.0001, paired t test; range, 2-11 mm Hg). CONCLUSION: Attempted eyelid closure during tonometry is a significant and common source of error in eyes with glaucoma and may influence the clinical management and decision-making in the treatment of NTG and HTG.

Adult↗
PubMed2002

Assessment of optic disc anatomy and nerve fiber layer thickness in ocular hypertensive subjects with normal short-wavelength automated perimetry.

PURPOSE: To compare optic disc topography and nerve fiber layer thickness in ocular hypertensive eyes and normal subjects. DESIGN: Prospective, case-controlled study. PARTICIPANTS AND CONTROLS: One eye in each of 20 normal and 27 ocular hypertensive patients was enrolled. METHODS: Consecutive normal and ocular hypertensive patients were enrolled. Each patient underwent complete ophthalmic examination, achromatic automated perimetry, short-wavelength automated perimetry, confocal scanning laser ophthalmoscopy, confocal scanning laser polarimetry, and optical coherence tomography. The intraocular pressure was 21 mmHg or less for normal subjects and at least 25 mmHg on two separate occasions in ocular hypertensive eyes. Structural parameters were compared between the two groups. Eyes with evidence of glaucomatous optic neuropathy, achromatic visual field loss, or evidence of focal visual field injury during short-wavelength automated perimetry were excluded. MAIN OUTCOME MEASURES: Optic nerve head topography and nerve fiber layer thickness. RESULTS: The three imaging technologies could not detect differences in optic disc or nerve fiber layer anatomy between the two groups. Ocular hypertensive eyes had a greater corrected pattern standard deviation than normal eyes during short-wavelength automated perimetry (P = 0.04). CONCLUSIONS: Ocular hypertensive eyes with normal achromatic automated perimetry and short-wavelength automated perimetry could not be distinguished from normal subjects with confocal scanning laser ophthalmoscopy, confocal scanning laser polarimetry, and optical coherence tomography.

Adult↗
PubMed2002

Chronic angle-closure with glaucomatous damage: long-term clinical course in a North American population and comparison with an Asian population.

PURPOSE: To study the long-term clinical course of North American chronic angle-closure glaucoma (CACG) patients with optic disc damage and visual field loss in the presence of an angle closed at least partially by peripheral anterior synechiae and to compare it with a similar group of Singaporean patients. DESIGN: A retrospective, interventional case-control study series. PARTICIPANTS: Fifty-one patients (80 eyes) diagnosed with CACG with glaucomatous optic nerve head and visual field damage at a New York hospital from January 1990 through December 1994. All study eyes underwent laser peripheral iridotomy (LPI). METHODS: The presenting features, management, and subsequent long-term intraocular pressure (IOP) outcome were analyzed and compared with 65 Asian patients (83 eyes) from a Singapore hospital who were similarly diagnosed during the same period. MAIN OUTCOME MEASURES: The long-term outcome after LPI was assessed in terms of IOP and the requirement for additional therapy. RESULTS: The mean presenting IOP was higher in the Singapore eyes (40 +/- 15 mmHg) compared with the New York eyes (31 +/- 12.5 mmHg). All 80 New York eyes (100%) and 78 of 83 Singapore eyes (94%) required further treatment to control IOP during follow-up. Of the eyes with a subsequent rise in IOP, 33 of 80 eyes (41.3%) compared with 34 of 83 eyes (41.0%) of the Singapore patients were controlled with additional topical medication. Of the New York eyes, 25 of 80 (31.3%) eventually underwent filtering surgery, compared with 44 of 83 (53.0%) in the Singapore study. The other 22 eyes (27.5%) in the New York group went on to additional laser procedures, peripheral iridoplasty, laser trabeculoplasty, or a combination thereof, after which IOPs were controlled and no surgery was required. There was no similar comparison for the Singapore group, because these eyes went directly on to surgery. CONCLUSIONS: Despite the presence of a patent LPI, most eyes with CACG presenting with elevated IOP and having both optic disc and visual field damage in both populations required further treatment to control IOP. Results in the American population are similar to that reported in Asian patients.

Aged↗
PubMed2002

Laser surgery for angle closure glaucoma.

The angle closure glaucomas are defined by iridotrabecular contact, trabecular dysfunction, and elevated intraocular pressure (IOP). Laser iridotomy successfully eliminates the relative pupillary block component of the angle closure process, regardless of whether the underlying angle closure is related primarily to pupillary block or another mechanism. For those eyes with angle closure originating at an anatomic level posterior to the iris, such as plateau iris, lens-induced angle closure, or posterior segment processes, argon laser peripheral iridoplasty is often useful to further open the angle. The purpose of this article is to review the indications and techniques for laser iridotomy and laser iridoplasty in clinical practice.

Glaucoma, Angle-Closure↗
PubMed2002

The efficacy of latanoprost is independent of the width of the ciliary body face.

PURPOSE: To assess the relation between the intraocular pressure-lowering efficacy of latanoprost 0.005% and the area of the ciliary body face exposed to the anterior chamber as assessed by ultrasound biomicroscopy. PATIENTS AND METHODS: Untreated, latanoprost-naive patients with ocular hypertension or open-angle glaucoma were enrolled in this prospective clinical trial. A radial, perpendicular ultrasound biomicroscopy image at the 6-o'clock position detailing Schwalbe line, scleral spur, and iris insertion was obtained. The distances between these structures were then measured and their relations to the intraocular pressure-lowering effect of latanoprost at 1, 2, 3, and 6 months were analyzed. RESULTS: Fifty-four eyes (54 patients) were enrolled. The mean age of participants was 60.2 +/- 13.9 years, and mean pretreatment intraocular pressure was 26.4 +/- 3.8 mm Hg. The mean intraocular pressure reduction from baseline was 7.1 mm Hg (26.9%), 7.3 (27.7%), 7.8 (29.5%), and 7.7 (29.2%) at 1, 2, 3 and 6 months, respectively. The mean distance between the scleral spur and the iris insertion was 0.14 +/- 0.08 mm (range, 0.04-0.33 mm). There was a significant correlation between intraocular pressure reduction at 1 month and trabecular meshwork height, suggesting that intraocular pressure reduction was associated with increasing trabecular meshwork height (P < 0.05). No other correlation could be found regarding intraocular pressure reduction. CONCLUSION: Although latanoprost lowers intraocular pressure by enhancing uveoscleral outflow, its efficacy is independent of the height of the ciliary face.

Antihypertensive Agents↗
PubMed2002

Angle closure in younger patients.

PURPOSE: Angle-closure glaucoma is rare in children and young adults. Only scattered cases associated with specific clinical entities have been reported. We evaluated the findings in patients in our database aged 40 or younger with angle closure. METHODS: Our database was searched for patients with angle closure who were 40 years old or younger. Data recorded included age at initial consultation; age at the time of diagnosis; gender; results of slit-lamp examination, gonioscopy, and ultrasound biomicroscopy (from 1993 onward); clinical diagnosis; and therapy. Patients with previous incisional surgery were excluded, as were patients with anterior chamber proliferative mechanisms leading to angle closure. RESULTS: Sixty-seven patients (49 females, 18 males) met entry criteria. Mean age (+/- SD) at the time of consultation was 34.4 +/- 9.4 years (range, 3-68 years). Diagnoses included plateau iris syndrome (35 patients), iridociliary cysts (8 patients), retinopathy of prematurity (7 patients), uveitis (5 patients), isolated nanophthalmos (3 patients), relative pupillary block (2 patients), Weill-Marchesani syndrome (3 patients), and 1 patient each with Marfan syndrome, miotic-induced angle closure, persistent hyperplastic primary vitreous, and idiopathic lens subluxation. CONCLUSION: The etiology of angle closure in young persons is different from that in the older population and is typically associated with structural or developmental ocular anomalies rather than relative pupillary block. Following laser iridotomy, these eyes should be monitored for recurrent angle closure and the need for additional laser or incisional surgical intervention.

Adolescent↗
PubMedDate not supplied

Hyphema occurring during selective laser trabeculoplasty.

The first case of hyphema occurring during selective laser trabeculoplasty in an eye without neovascularization is described. A 77-year-old man with uncontrolled open-angle glaucoma received selective laser trabeculoplasty in both eyes for high intraocular pressure with maximally tolerated medical treatment. Hyphema occurred during selective laser trabeculoplasty in the left eye. This resolved spontaneously without sequelae. Successful intraocular pressure control was achieved. Hyphema and bleeding can happen during selective laser trabeculoplasty. Although this was transient and uneventful in one patient, careful monitoring of intraocular pressure and anterior chamber reaction is advised.

Aged↗
PubMedDate not supplied

A new silicone eyecup for ultrasound biomicroscopy.

This study compared a new disposable silicone eyecup for high-frequency ultrasound biomicroscopy to the standard hard plastic eyecup. The results showed the silicone eyecup attenuated leakage of the medium in which the probe was immersed, decreased scanning time, decreased distortion of the iris and angle during scanning, enhanced image quality, and improved patient comfort. These findings indicate the silicone eyecup is a good alternative to the hard plastic eyecup and also is easier to use.

Anterior Eye Segment↗
PubMedDate not supplied

Acute conformational changes in the optic nerve head with rapid intraocular pressure elevation: implications for LASIK surgery.

BACKGROUND AND OBJECTIVE: To investigate the effects of acute intraocular pressure (IOP) elevation on optic disc morphology. PATIENTS AND METHODS: Ophthalmodynamometry was used to increase the IOP of normal, healthy eyes. Confocal scanning laser ophthalmoscopy of the optic nerve head using the Heidelberg Retinal Tomograph II (Heidelberg GmbH, Heidelberg, Germany) and IOP measurements were obtained before, during, and after IOP elevation. RESULTS: Sixteen eyes of 16 normal volunteers (mean age, 32.8 +/- 11.9 years) were enrolled. Rim area, rim volume, cup area, cup volume, cup-to-disc ratio, mean cup depth, maximum cup depth, mean retinal nerve fiber layer (RNFL) thickness, and RNFL cross-sectional area showed significant changes during IOP elevation (all P < .05, paired t test). All measured parameters returned to their original values after pressure resolution (all P > .2) except mean RNFL thickness (P = .03). CONCLUSION: Transient elevation of IOP results in measurable alterations in optic nerve head topography.

Adult↗
PubMedDate not supplied

A conjunctival retractor for glaucoma filtering surgery.

A new conjunctival retractor provides the desired exposure of the scleral bed during filtering surgery. It elevates the conjunctiva without causing crush injury and allows excellent exposure of the scleral bed with a smaller incision than is required when non-toothed forceps or Weck cell sponges are used. The surgeon or assistant holding the retractor can move it in various directions to provide a good view of any particular site for which exposure is needed.

Conjunctiva↗