Biomedical subjects

Jeffrey M Liebmann

Publications and source records attributed to Jeffrey M Liebmann.

At least 37 records · Page 2Linked to original sources

PubMed2005

The Low-pressure Glaucoma Treatment Study (LoGTS) study design and baseline characteristics of enrolled patients.

OBJECTIVE: The Low-Pressure Glaucoma Treatment Study (LoGTS) seeks to evaluate visual field stability in low-pressure glaucoma patients randomized to intraocular pressure reduction in both eyes with topical twice daily brimonidine tartrate 0.2% versus twice daily timolol maleate 0.5%. This article describes the LoGTS design and presents baseline characteristics of the subjects. DESIGN: Randomized, multicenter, double-masked clinical trial. PARTICIPANTS: Low-pressure glaucoma patients 30 years of age or older were identified. Exclusion criteria included an untreated pressure of more than 21 mmHg, advanced visual field loss, and contraindications to study medications. INTERVENTIONS: Randomization of both eyes to double-masked monotherapy with brimonidine or timolol. Follow-up visits included Humphrey 24-2 full-threshold perimetry, tonometry every 4 months, and annual optic disc photography. MAIN OUTCOME MEASURE: Progression of visual field loss. RESULTS: One hundred ninety patients were randomized between 1998 and 2000. Mean age (+/-standard deviation) was 64.9+/-10.7 years. Women comprised 59.5% of the patients. Fifty-three patients (27.9%) had unilateral field loss. The 137 patients with bilateral field loss were older than those with unilateral field loss: 65.7 versus 62.3 years of age (P<0.05). Mean untreated diurnal intraocular pressures were similar between the eyes of the bilateral patients (mean, 15.5 mmHg in both eyes) and unilateral patients (mean, 16.0 mmHg in field loss vs. 15.6 mmHg in fellow eyes). Visual field mean deviation for all eyes was -5.4+/-4.7 decibels. Central corneal thickness in 168 phakic patients was 543 +/- 35 microm (range, 435-655 microm); thickness was less than 500 microm in 15 eyes and was more than 600 microm in 11 eyes. Mean vertical cup-to-disc ratio for all eyes was 0.67+/-0.15. Unilateral field loss patients had a larger cup-to-disc ratio in the field loss eye (0.75+/-0.12) than the fellow eye with a normal field (0.60+/-0.17, P<0.0001). Disc hemorrhage was present at baseline in 29 patients (32 eyes). CONCLUSIONS: The LoGTS was successfully able to recruit and enroll patients with open-angle glaucoma and statistically normal intraocular pressure into a longitudinal, prospective clinical trial comparing 2 different glaucoma medications. Baseline characteristics of note were a preponderance of females, unilateral field loss in 27.9% of participants, and frequent optic disc hemorrhage. Central corneal thickness had a normal distribution and did not account for false low-pressure measurements in LoGTS patients.

Adult↗

PubMed2005

Central corneal thickness measurement in clinical practice.

OBJECTIVE: To determine if a single measurement of central corneal thickness (CCT) is an adequate sample to aid in glaucoma risk assessment in clinical practice. METHODS: Central corneal thickness was measured by ultrasound pachymetry (mean of 15 measurements for each eye) on two separate occasions at least one month apart (range, 33 to 610 days). Eyes with a history of prior incisional surgery or corneal pathology were excluded. RESULTS: Ninety-eight eyes of 98 patients (43 male, 55 female) were enrolled. Mean age was 61.2 +/- 15.5 years. Mean inter-test period was 276 +/- 124 days. No significant difference in mean CCT was observed between the two visits (549 +/- 41 microm versus 548 +/- 42 microm, P = 0.4, two-tailed, paired t test). Measured CCT values differed by more than 20 microm in 20 eyes (20.4%), whereas CCT difference of at least 40 microm was seen in 5 eyes (5.1%). There was no correlation between the measured or absolute difference in CCT and IOP (r = -0.016, P > 0.43), inter-test time period (r = 0.072, P > 0.23), and glaucoma diagnosis. CONCLUSION: Central corneal thickness measurements in this study differed by at least 20 microm in 20% of eyes. This has important implications for risk assessment, management, and follow-up of patients with glaucoma and related disorders. Factors affecting CCT measurement, such as examiner error or true alterations in corneal thickness, require continued investigation.

Adolescent↗

PubMed2005

Hypophosphorylation of aqueous humor sCD44 and primary open-angle glaucoma.

PURPOSE: The ectodomain of CD44, the principal receptor for hyaluronic acid (HA), is shed as a 32-kDa fragment-soluble CD44 (sCD44)-which is cytotoxic to trabecular meshwork (TM) cells and retinal ganglion cells (RGCs) in culture. The purpose of this study was to characterize sCD44 further by determining the phosphorylation of aqueous humor sCD44 in normal and primary open-angle glaucoma (POAG). METHODS: Aqueous humor samples of patients were subjected to CD44 enzyme-linked immunosorbent assay (ELISA) and two-dimensional (2-D) polyacrylamide gel electrophoresis, followed by Western blot analysis with anti-CD44, anti-serine/threonine, and anti-tyrosine phosphospecific antibodies, to determine sCD44 concentration, isoelectric point (pI), and phosphorylation, respectively. The bioactivity of hypophosphorylated sCD44 was tested in cell culture and HA affinity columns. RESULTS: Two-dimensional Western blot analysis revealed that the representative pI of the 32-kDa sCD44 was 6.96 +/- 0.07 in POAG versus 6.38 +/- 0.08 in normal (P < 0.0004). Enzymatic dephosphorylation of sCD44 resulted in a basic shift in the pI. The normal aqueous humor sCD44 was positive for serine-threonine phosphorylation; however, POAG sCD44 was hypophosphorylated. Hypophosphorylated sCD44 was more toxic to TM and RGC cells than standard sCD44, and hypophosphorylated sCD44 had decreased affinity to HA, particularly with increased pressure. CONCLUSIONS: POAG aqueous is characterized by posttranslational change in the pI of sCD44 and hypophosphorylation, which clearly distinguished POAG from normal aqueous humor. The high toxicity and low HA-binding affinity of hypophosphorylated sCD44 may represent specific pathophysiologic features of the POAG disease process.

Aqueous Humor↗

PubMed2005

The pattern electroretinogram in glaucoma patients with confirmed visual field deficits.

PURPOSE: To better understand the relationship between the amplitude of the pattern electroretinogram (PERG) and visual loss, measured with static automated perimetry. METHODS: Transient PERGs were recorded in 15 patients (31-77 years) and 16 normal individuals (26-65 years). An eye was considered to have glaucomatous damage only if there was an abnormal disc, an abnormal 24-2 Humphrey visual field result (pattern stand deviation, glaucoma hemifield test, and cluster) and an abnormal multifocal visual evoked potential. All the worse (more affected) eyes of the patients and six of the better eyes met these criteria. The N95 amplitude of the PERG was measured from the positive peak (P50) at approximately 50 ms to the trough at approximately 95 ms. The ratio of N95 to P50-the N95 amplitude divided by the P50 amplitude-was also measured. RESULTS: First, the PERG was within normal limits for 4 (26.7%) of the worse eyes. Overall, 6 (28.6%) of the 21 eyes that met the criteria for glaucomatous damage had normal PERGs on both PERG measures. Because the normal individuals were younger than the patients, an even larger number of normal PERGs might be expected with an age-appropriate control group. Second, the N95 amplitude was nonlinearly related to visual field sensitivity when sensitivity was plotted on a linear plot. Small field losses were associated with disproportionately large losses in PERG amplitude. Third, the PERG from both eyes of a patient were very similar, even when the visual fields suggested very different levels of damage. CONCLUSIONS: These results are consistent with the view that very early damage can affect the PERG, even before the visual field shows a loss. At the same time, it is clear that patients with clear glaucomatous damage can have normal-appearing PERGs. An explanation is proposed to account for these findings.

Adult↗

PubMed2004

Racial differences in optic disc topography: baseline results from the confocal scanning laser ophthalmoscopy ancillary study to the ocular hypertension treatment study.

OBJECTIVE: To examine racial differences in optic disc topography among ocular hypertensive participants in the Ocular Hypertension Treatment Study. METHODS: Four hundred thirty-nine participants from 7 Ocular Hypertension Treatment Study centers who had good-quality baseline images obtained using a quantitative 3-dimensional confocal scanning laser ophthalmoscope, the Heidelberg Retina Tomograph (Heidelberg Engineering, Dossenheim, Germany), were included in this study. The first 10 degrees- or 15 degrees-field of view mean topographic image acquired was included in all analyses. Differences in Heidelberg Retina Tomograph topographic optic disc parameter measurements by self-identified race were assessed using a mixed-effects linear model to control for confounders and for the use of both eyes in the model. RESULTS: By self-attribution, 74 (17%) of the 439 participants were of African origin, 329 (75%) were white, 24 (5%) were Hispanic, and 12 (3%) were Native American, Native Alaskan, Asian, Pacific Islander, or unknown. The African American participants had statistically significantly (P<.001) larger mean (SD) optic disc areas than the other participants, 2.17 (0.41) mm(2) vs 1.87 (0.38) mm(2), respectively. African American participants had a larger cup area, cup volume, cup depth, neuroretinal rim area, rim volume, and smaller rim-optic disc area ratios than the other participants. No difference between African American and the other participants was found for cup shape and retinal nerve fiber layer thickness. After controlling for optic disc area, none of the differences between African American and the other participants found in the univariate analysis remained statistically significant (P>.10). CONCLUSIONS: This study demonstrated in a large cohort of subjects with ocular hypertension, that African Americans have significantly larger optic discs, optic cups, neuroretinal rims, and cup-disc ratios than other racial groups. Furthermore, this study found that differences in topographic optic disc parameters between African Americans with ocular hypertension and other racial groups are largely explained by the larger optic disc area in the African Americans. These results highlight the need to consider race and optic disc size when evaluating the appearance of the optic disc in glaucoma.

Antihypertensive Agents↗

PubMed2004

A method for comparing electrophysiological, psychophysical, and structural measures of glaucomatous damage.

OBJECTIVE: To develop a method for comparing multifocal visual-evoked potential (mfVEP) responses and behaviorally determined visual fields with structural measures of the optic nerve head. METHODS: Humphrey 24-2 visual fields and mfVEPs were obtained from each eye of 20 patients with open-angle glaucoma. Monocular and interocular analyses were performed to identify locations with abnormal mfVEP responses. Optic discs were assessed with a confocal scanning laser ophthalmoscope (Heidelberg Retina Tomograph II). The image of the optic nerve head was divided into 6 sectors. The rim and disc area measurements for each sector were compared with those in a normal database using Moorfields regression analysis. The optic nerve head measurements for the 6 sectors were related to the Humphrey visual field locations and the 60 sectors of the mfVEP display. RESULTS: Of 240 sectors tested (40 eyes x 6 sectors), 18.8% on Humphrey visual field, 22.1% on mfVEP, and 10.8% on confocal scanning laser ophthalmoscopic testing were significantly different from those of control subjects. There were no significant deficits in 165 sectors. There was agreement for 86.7% of the sectors when the Humphrey visual field and mfVEP results were compared. The confocal scanning laser ophthalmoscopic results were in agreement for 84.6% of these sectors. CONCLUSIONS: The method used allows for a comparison among measures of visual function and a structural measure of the optic nerve head. In general, the results of the functional and structural measures showed agreement; however, there were clear examples of disagreements that merit further study.

Adult↗

PubMed2004

The confocal scanning laser ophthalmoscopy ancillary study to the ocular hypertension treatment study: study design and baseline factors.

PURPOSE: To describe the study design of the Confocal Scanning Laser Ophthalmoscopy (CSLO) Ancillary Study to the Ocular Hypertension Treatment Study (OHTS) and to examine the associations between optic disk topography, and baseline demographic, clinical, and ocular factors at study entry. DESIGN: A randomized clinical trial. METHODS: Participants in this ancillary study were recruited from seven of the 22 OHTS clinical centers. Each participant completed imaging annually using a CSLO, the Heidelberg Retina Tomograph (HRT). Associations between HRT topographic optic disk measurements and intraocular pressure (IOP), baseline photographic estimates of horizontal and vertical cup-to-disk diameter ratios by the OHTS Optic Disk Reading Center, baseline visual field indices, and demographic and clinical factors were assessed using linear mixed effects models. RESULTS: Four hundred thirty-nine participants had good quality images and were included in this baseline analysis. No associations between HRT topographic optic disk measurements and diabetes, systemic hypertension, cardiovascular disease, IOP, or visual function were found. The HRT topographic optic disk measurements were associated with baseline stereophotographic estimates of horizontal and vertical cup-to-disk diameter ratios. The strongest associations were found between stereophotographic assessment of horizontal and vertical cup-to-disk diameter ratios, and HRT cup-to-disk area ratio (r =.85 and.84, respectively), rim-to-disk area ratio (r = -.85 and -.84, respectively), mean cup depth (r =.84 and.83, respectively), and cup area (r =.83 and.80, respectively). After adjusting for optic disk area, all HRT topographic optic disk measurements remained associated with stereophotographic assessment of horizontal and vertical cup-to-disk diameter ratios. CONCLUSIONS: The CSLO ancillary study to the OHTS is the first multicenter clinical trial to use CSLO imaging to monitor changes in the optic disk. At study entry, HRT topographic measurements corresponded well with both horizontal and vertical stereophotographic-based estimates of cup-to-disk diameter ratio in ocular hypertensive participants.

Female↗

PubMed2004

Risk assessment in the management of patients with ocular hypertension.

PURPOSE: To develop a model for estimating the global risk of disease progression in patients with ocular hypertension and to calculate the "number-needed-to-treat" (NNT) to prevent progression to blindness as an aid to practitioners in clinical decision making. DESIGN: Development of a mathematical model for estimating risk of glaucoma progression. METHODS: Population-based studies of patients with ocular hypertension and glaucoma were reviewed by a panel of glaucoma specialists. Measures of disease progression risks derived from three long-term studies and assumptions based on the available data were used to estimate the risk of progression from ocular hypertension to glaucoma and glaucoma to unilateral blindness for untreated and treated patients over a 15-year period. Using these estimates, the NNT (1/absolute risk reduction on treatment) to prevent unilateral blindness in one patient with ocular hypertension was calculated. RESULTS: In untreated patients, the estimated risk of progression from ocular hypertension to unilateral blindness was 1.5% to 10.5% and in treated patients, the estimated risk of progression was 0.3% to 2.4% over 15 years. From these estimates, between 12 and 83 patients with ocular hypertension will require treatment to prevent one patient from progressing to unilateral blindness over a 15-year period. CONCLUSION: Global risk assessment that incorporates all available data plays a vital role in managing patients with ocular hypertension. A more precise understanding of long-term vision loss should be factored into decisions pertaining to the initiation of glaucoma therapy. Undoubtedly, these estimates will evolve and change with the availability of new population-based epidemiologic information and improvements in multivariable model testing.

Blindness↗

PubMed2004

An evidence-based assessment of risk factors for the progression of ocular hypertension and glaucoma.

PURPOSE: To critically review the existing literature concerning risk factors for progression of ocular hypertension and glaucoma to assist in assigning levels of risk for individual patients. DESIGN: Evidence-based review. METHODS: A panel of physicians specializing in treatment of glaucoma patients was convened to critically analyze published population-based studies of ocular hypertension and glaucoma progression. The strength of evidence in support of reported risk factors was weighed. RESULTS: Many putative risk factors for progression of ocular hypertension or glaucoma have been reported in the literature. The risk factors most strongly supported by evidence are higher intraocular pressure (IOP), greater cup-to-disk ratio, thinner central corneal measurement, and older age. Black race does not appear to be an independent risk factor, although black individuals tend to have thinner corneas, greater cup-to-disk ratios, and higher IOP, which increase their risk. The limited number of studies in which other suspected risk factors are reported prevents drawing firm conclusions about their importance at this time. CONCLUSIONS: Only a subset of patients with ocular hypertension will eventually develop glaucoma. Decisions regarding the implementation and extent of therapy for ocular hypertension can be difficult and require an understanding of the relative importance of risk factors for progression. This review discusses the strength of evidence supporting reported risk factors and may be useful in assessing the risk for progression of individual patients.

Disease Progression↗

PubMed2004

The Proview phosphene tonometer fails to measure ocular pressure accurately in clinical practice.

PURPOSE: To evaluate the Proview Eye Pressure Monitor as a medical instrument and as a technique for enabling a patient to obtain an accurate measure of his or her intraocular pressure (IOP). DESIGN: An experimental laboratory evaluation and an independent prospective clinical study to test the reproducibility and accuracy of the Proview technique relative to Goldmann applanation tonometry. PARTICIPANTS: For the laboratory study, we analyzed 3 tonometers, each packaged as a Proview Eye Pressure Monitor by Bausch & Lomb. In the independent prospective experimental study, 137 subjects participated, consisting of healthy volunteers and glaucoma patients. METHODS: For laboratory testing, we held each tonometer with a micrometer to assure controlled positioning and pressed its sensing tip against a force meter that produced a calibrated, digital force reading. For clinical testing, we taught subjects (n = 137) to use the Proview technique in accordance with the manufacturer's instructions. Each subject obtained 5 measurements with each of the 5 different Proview devices. A clinician measured the IOP using Goldmann applanation tonometry. MAIN OUTCOME MEASURES: We measured the absolute value, linearity, and repeatability of the force meter readings on the tonometers during the instrument laboratory evaluation. The accuracy was evaluated by comparing the Proview measurements to the Goldmann applanation measurements. Reproducibility of clinical Proview measurements was also measured. All measurements were in mmHg during the clinical evaluation. RESULTS: Laboratory: There was a linear relationship between the pressures read by the Proview tonometers and known forces. The Proview tonometers read the maximum pressure applied. Clinical: The Proview technique is simple to use because it was comfortable and reproducible, with an average variance of the measurements by the same patient of 3.4 mmHg(2). Other variables besides IOP seem to affect the Proview pressure measurements, as seen in the large scatter in our data, measured by our correlation coefficient of r = 0.41. The sensitivity of the Proview technique to detect patients with high IOP (which we defined as a Goldmann pressure of >/=22 mmHg) is low; the Proview pressure identified only 18% (4/22) of these patients. CONCLUSIONS: The Proview instrument and technique were reproducible. However, the Proview tonometer seems not to be reliable as an indicator of IOP. The sensitivity for detecting high IOP was low in this cohort, and the agreement with Goldmann applanation was poor for some individuals. This brings into question the underlying assumption that a force proportional to the IOP generates phosphenes.

Adolescent↗

PubMed2004

Evolving guidelines for intravitreous injections.

Intravitreous (i.v.t.) injection is increasingly being incorporated into the management of ocular diseases. While only fomivirsen sodium (Vitravene) is currently approved by the Food and Drug Administration as an i.v.t. injection, the number of approved i.v.t. injections indications is anticipated to grow on the basis of promising results from ongoing clinical studies. Despite the potential benefits that may be derived from intraocular injections of different agents, no guidelines have been published previously for i.v.t. injection. The purpose of this document is to identify specific strategies for the delivery of i.v.t. injection that may reduce risks and improve outcomes. Consensus was sought among a panel of investigators, surgeons experienced with this technique, and industry representatives. Objective evidence was sought for all guidelines, but consensus was accepted where evidence remains incomplete. In the absence of either evidence or consensus, the current manuscript identifies outstanding issues in need of further investigation. It is anticipated that more complete guidelines will evolve over time, potentially altering some of the guidelines included here, based on new applications of i.v.t. injection, additional clinical experience, and results of clinical trials.

Humans↗

PubMed2004

Effect of pupillary dilation on retinal nerve fiber layer thickness measurements using optical coherence tomography.

PURPOSE: To evaluate the effect of pupillary dilation on retinal nerve fiber layer thickness (RNFL) measurements using optical coherence tomography (OCT-3). METHODS: Randomly chosen eyes of healthy individuals were scanned before and after pupillary dilation by two trained operators (R.G.O., R.V.) using OCT-3 (Carl Zeiss Meditec, Inc., Dublin, CA). Fast and regular RNFL (256 A-scans) OCT-3 protocols (software version A1.1) were used in each scanning session. RNFL thickness measurements before and after dilation were compared. RESULTS: Ten eyes of 10 subjects (6 females, 4 males) were enrolled. Mean age was 32.0 +/- 11.2 years (range, 21 to 52 years). Mean pupillary diameter before and after dilation was 2.9 +/- 0.6 mm and 7.6 +/- 0.8 mm, respectively (P < 0.0001, paired t-test). There was no significant difference in RNFL thickness measurements before and after dilation using both fast and regular RNFL protocols (P > or = 0.05 for all comparisons, paired t-test). Mean coefficients of variation for mean RNFL thickness measurements were 15.3% before and 13.7% after dilation for operator 1; and 10.8% before and 12.7% after dilation for operator 2 for the fast RNFL protocol and 11.3% versus 10.4% and 12.9 versus 11.1%, respectively, for the regular RNFL protocol. CONCLUSION: Pupillary dilation is not necessary in all subjects to obtain reproducible RNFL thickness measurements using OCT-3.

Adult↗

PubMed2004

Scanning protocol choice affects optical coherence tomography (OCT-3) measurements.

PURPOSE: To determine the optimal OCT-3 scanning protocol. METHODS: Normal subjects, ocular hypertensive, and open-angle glaucoma patients were enrolled. The "fast" RNFL scan protocol consists of 3 consecutive circular scans, each containing 256 A-scans obtained in a single 1.92 second session. The "regular" RNFL scan protocol contains 3 separate circular scans, each of which consists of 512 A-scans and is obtained in 1.28 seconds (total 3.84 seconds). A customized 256-point scan was created from the 512-point "regular" RNFL scan by extracting the RNFL measurements from every second point. Mean RNFL thickness measurements and mean coefficients of variation (CV) were calculated for each of the scan types. RESULTS: Thirty-one eyes with visual field defects (31 glaucoma eyes) and 30 eyes with normal fields (10 normal and 20 ocular hypertensive eyes) were enrolled. There was no difference in RNFL thickness or CV between fast, regular, or customized RNFL scans in the eyes with VF defects (P > 0.05 for all comparisons). Although eyes with normal fields showed no difference in CV between fast, regular, and customized RNFL scans (P > 0.05 for all comparisons), there was a thicker RNFL measurement using the fast RNFL scan (P = 0.01). CONCLUSIONS: Optimal sampling density for OCT-3 assessment of parapapillary RNFL thickness is not more than 256 axial determinations. Although both scanning protocols have good reproducibility, the scanning protocol should remain constant during serial OCT-3 evaluation.

Adult↗

PubMed2004

Macular and retinal nerve fiber layer thickness measurement reproducibility using optical coherence tomography (OCT-3).

PURPOSE: To assess the reproducibility of retinal nerve fiber layer thickness and macular thickness measurements using OCT-3. METHODS: Randomly chosen eyes of healthy individuals were scanned following pupillary dilation by two trained operators (RGO, RV) using OCT-3 (software version A1.1, Carl Zeiss Meditec, Inc., Dublin, CA), three times on separate days within a one-month period. Fast and regular macula (128 A-scans), and fast and regular RNFL (256 A-scans) scanning protocols were performed. Intra- and interoperator measurement reproducibility was evaluated. RESULTS: Ten eyes of 10 subjects (6 females, 4 males) were enrolled. Mean age was 32 +/- 11.2 years (range, 21 to 52 years). Intraoperator reproducibility was high for both macular and RNFL thickness measurements. Mean coefficients of variation (CV) for mean total RNFL thickness measurements ranged from 6.9 +/- 6.4% to 8.0 +/- 3.5% for operators 1 and 2 in fast and regular RNFL protocols. Mean CV for mean macular thickness measurements ranged from 4.7 +/- 2.6% to 6.4 +/- 5.5% for operator 1 and 2 in fast and regular macula protocols. There was no difference in mean total RNFL and mean foveal thickness measurements performed on different days (P > 0.05 for all measurements in all protocols, for operators 1 and 2, ANOVA). Interoperator reproducibility was high for both macular and RNFL thickness measurements (P > 0.05 for all measurements in all protocols, paired t test). CONCLUSION: OCT-3 RNFL and macular thickness measurements are reproducible in normal eyes. These results should be validated in ocular hypertensive and glaucomatous eyes.

Adult↗

PubMed2004

Detecting early to mild glaucomatous damage: a comparison of the multifocal VEP and automated perimetry.

PURPOSE: To gain better understanding of the relationship between abnormalities detected by the multifocal VEP (mfVEP) compared with those detected by static achromatic, automated perimetry in patients with glaucoma. METHODS: Fifty patients were studied who had open-angle glaucoma that met the following criteria: (1) a mean deviation (MD) of better than -8 dB in both eyes on the 24-2 Humphrey visual field (HVF) test (Carl Zeiss Meditec, Dublin, CA); and (2) glaucomatous damage in at least one eye, as defined by a glaucomatous optic disc and an abnormal 24-2 HVF test result (pattern standard deviation [PSD] <5% and/or glaucoma hemifield test [GHT] results outside normal limits). Monocular mfVEPs were obtained from each eye by using a pattern-reversal dartboard array, 44.5 degrees in diameter, which contained 60 sectors. Recording electrodes were placed at the inion (I) and I+4 cm, and also at two lateral locations up 1 cm and over 4 cm from I. Monocular and interocular mfVEP probability plots were derived by comparing the results with those of normal control subjects. For both the HVF and mfVEP probability plots, a hemifield was classified as abnormal if three or more contiguous points were significant at less than 5%, with at least one at less than 1%. RESULTS: Of the 200 hemifields tested (50 patients x two eyes x two hemifields), 75 showed significant clusters on the HVF, and 74 (monocular probability plot) and 93 (monocular or interocular plot) showed significant clusters on the mfVEP. Overall, the HVF and mfVEP results agreed on 74% of the hemifields, and 90 hemifields were normal and 58 were abnormal on both the mfVEP (interocular and/or monocular abnormal) and HVF cluster tests. Of the 52 disagreements, 35 hemifields had a significant cluster on the mfVEP, but not on the HVF, whereas the reverse was true of 17 hemifields. A case-by-case analysis indicated that misses and false-positive results occurred on both the HVF and mfVEP tests. CONCLUSIONS: As predicted from a theoretical analysis, under these conditions (i.e., the signal-to-noise level) the HVF and monocular mfVEP tests showed a comparable number of defects, and, with the addition of the interocular test, the mfVEP showed more abnormalities than the HVF. However, although there were abnormalities detected by the mfVEP that were missed by the HVF, the reverse was true as well.

Adult↗

PubMed2003

Iridociliary apposition in plateau iris syndrome persists after cataract extraction.

PURPOSE: To evaluate the ultrasound biomicroscopic appearance of the anterior segment before and after cataract extraction in eyes with plateau iris syndrome and to determine the effect of postoperative zonular relaxation on ciliary body position. DESIGN: Interventional case series. METHODS: Eyes with plateau iris syndrome scanned before and after cataract extraction between January 1994 and September 2001 were enrolled. The iridociliary relationship and the anterior chamber depth at a distance of 3 mm from the scleral spur were assessed. RESULTS: We examined six eyes of six patients. Mean patient age was 74.2 +/- 6.4 years (standard deviation [SD]) (range, 65-81 years). Mean refractive error was + 1.0 +/- 3.9 diopters [D] (range, -5.75-+5.50), and mean axial length was 21.85 +/- 0.77 mm (range, 20.90-22.95 mm). All eyes had undergone laser iridotomy and argon laser peripheral iridoplasty before cataract extraction. Ultrasound biomicroscopy examination revealed a narrow angle and absence of a ciliary body sulcus in all eyes with focal areas of iridotrabecular apposition in three eyes. Following cataract extraction, the anterior chamber depth increased (P =.0006, paired t test), while the iridociliary contact remained unchanged. CONCLUSIONS: Iridociliary apposition persists after cataract extraction in plateau iris syndrome. Whether the cause is congenital or acquired, or both, remains to be determined.

Aged↗

PubMed2003

An improved technique of eye drop self-administration for patients with limited vision.

PURPOSE: To describe a new, highly accurate, tactile technique to increase accuracy in the self-administration of eye drops. DESIGN: Interventional case series. METHODS: Ten adult patients with loss of fixation (< or = 20/400) in one eye and ten adult patients with loss of fixation in both eyes instilled one drop of artificial tears in each eye using the technique normally employed at home. The time required to instill each drop, the number of drops squeezed from the bottle, and location of the drops' landing points on the face or eye were recorded. The patients were then instructed in a new technique for instillation, guided through the procedure once, and allowed to practice until comfortable with it. All measurements were then repeated. RESULTS: In patients with loss of fixation in one eye, an additional 3.2 +/- 4.1 seconds were required to instill a drop using the new technique (P <.0001, paired t test; range, -7-18 seconds). The mean number of drops dispensed decreased by 0.1 +/- 0.6 drops (P =.60, paired t test; range, -2-1 drop). The accuracy of drop placement increased from 80.0% to 82.5% (P =.32, paired t test). In subjects with loss of fixation in both eyes, using the new technique increased the time needed to instill a drop by 3.8 +/- 3.8 seconds (P <.0001, paired t test; range, -3-13 seconds). The average number of drops dispensed decreased by 0.1 +/- 0.6 drops (P =.25, paired t test; range, -2-1 drop). The accuracy of placement increased from 63.0% to 85.0% (P =.001, paired t test). CONCLUSIONS: This technique of drop instillation may be beneficial for patients with significant visual impairment in both eyes.

Adult↗

PubMed2003

Plasma homocysteine is elevated in patients with exfoliation syndrome.

PURPOSE: To compare plasma homocysteine concentrations among patients with exfoliation syndrome, exfoliative glaucoma, normal-tension glaucoma, and normal control subjects without vascular or inflammatory ocular disease or glaucoma. DESIGN: Cross-sectional study. METHODS: We tested 25 patients with exfoliation syndrome, 50 with exfoliative glaucoma, 25 with normal-tension glaucoma, and 24 control subjects. Fasting plasma homocysteine concentrations were measured by fluorescence polarization immunoassay. Patients using vitamin supplements or medications known to alter serum homocysteine were excluded. RESULTS: Homocysteine levels were higher in both exfoliatin groups compared with controls (exfoliation syndrome: P =.003; exfoliative glaucoma: P =.009); levels in normal-tension glaucoma were higher than but not significantly different from those in controls (P =.2). Hyperhomocysteinemia was present in 16 of 25 (64%) exfoliation syndrome patients, 28 of 50 (56%) exfoliative glaucoma patients, 13 of 25 (52%) normal-tension glaucoma patients, and 7 of 24 (29.2%) controls (P =.005). Multiple logistic regression analyses comparing exfoliation syndrome and exfoliative glaucoma patients with controls indicated that elevated plasma homocysteine concentration was a significant risk factor for exfoliation syndrome, in both those patients (odds ratios per 1.0 micromol/l increase in plasma homocysteine concentrations = 1.47; 95% confidence interval [CI] = 1.08-2.0) and in exfoliative glaucoma patients (odds ratio = 1.3; 95% CI = 1.07-1.6). Although exfoliative glaucoma and normal-tension glaucoma patients were not significantly different with respect to hyperhomocysteinemia, logistic regression modeling of exfoliative glaucoma vs normal-tension glaucoma patients showed that an increased homocysteine concentration was a significant risk factor for exfoliation syndrome in the presence of glaucoma (odds ratio per 1.0 micromol/l increase in homocysteine = 1.2, 95% CI = 1.0-1.4). These relationships were not affected by adjustment for potential confounding due to sex, history of hypertension, or other factors. RESULTS: Elevated plasma homocysteine, a risk factor for cardiovascular disease, is more common in exfoliation syndrome and exfoliative glaucoma patients than healthy controls. Patients with exfoliation syndrome may benefit from measurement of homocysteine levels.

Aged↗