Faculty Bibliography

Purpose: To evaluate the fellow eye of unilateral Exfoliation Syndrome (XFS) and Exfoliation Glaucoma (XFG) patients using SD-tVEP. Methods: The study population was divided into three age-matched groups: 1) 15 randomly selected eyes of 15 healthy subjects (70.2+/-5.4 yr); 2) 30 eyes of 15 unilateral XFS patients (73.9+/-6.0 yr); and 3) 26 eyes of 13 unilateral XFG patients (70.5+/-9.1 yr). SD-tVEP's were recorded using the Diopsys NOVA System (Diopsys, Inc. Pine Brook, NJ). An area under the curve (AUC) analysis of the SD-tVEP parameters was performed comparing the XFS/XFG eyes and the healthy eyes. 1-way ANOVA was performed on the SD-tVEP parameters to determine if significant differences existed between the XFS/XFG eye and the unaffected fellow eyes; between the XFS and XFG eyes; between the XFS/XFG fellow eye and the healthy eyes; and between the XFS/XFG and the healthy eyes. Results: No significant difference was found between the XFS/XFG and fellow eye (p=0.43, p=0.21 respectively) under SD-tVEP parameters, nor was one found between the XFS and XFG eyes (p=0.39). In addition, the differences between both XFS/XFG fellow eyes and the healthy eyes approached but were not significant (p=0.054, p=0.06). However, significant differences were found between both XFS/XFG eyes and the healthy eyes (p=0.01, p=0.03 respectively). Comparing the healthy eyes to the XFS/XFG eyes, the AUC for the XFS eyes was Hc P100 amplitude 0.77 (0.58 - 0.96); Hc P100 latency 0.75 (0.56 - 0.93); Lc P100 amplitude 0.71 (0.50 - 0.91); and Lc latency 0.74 (0.56 - 0.93) and the AUC for the XFG eyes was Hc P100 amplitude 0.78 (0.59 - 0.97); Hc P100 latency 0.84 (0.67 - 1.00); Lc P100 amplitude 0.76 (0.57 - 0.95); and Lc latency 0.75 (0.55 - 0.95). Conclusions: Short-duration transient VEP may be capable of detecting subtle alterations in the uninvolved fellow eye of unilateral XFS/XFG eyes prior to other abnormalities. Further study with a larger number of patients is needed to confirm these preliminary findings

BACKGROUND: To investigate anatomical configuration of ciliary body and iris using ultrasound biomicroscopy as a predictor of malignant glaucoma development. DESIGN: Retrospective study in a tertiary care hospital. PARTICIPANTS: Cohort of 31 consecutive patients diagnosed with post-surgical malignant glaucoma. METHODS: Anterior chamber angle, iris and ciliary body configuration of involved eyes that had ultrasound biomicroscopy evaluation prior to the malignant glaucoma onset were evaluated. In cases with no presurgical ultrasound biomicroscopy exam of the involved eye, images from the fellow eye (imaged within 6 months) were analysed. MAIN OUTCOME MEASURES: Qualitative parameters. RESULTS: Thirty-one eyes (31 patients) had confirmed malignant glaucoma between 1996 and 2008. Most patients were women (65%) and had an anatomical narrow angle or angle-closure glaucoma (77%). Mean intraocular pressure at diagnosis was 30.4 +/- 13.5 mmHg. The most common operation was trabeculectomy with mitomycin C (55%, 17/31 eyes), combined (3/17) or not (14/17) with cataract extraction and intraocular lens implantation. Among these 31 cases, we were able to evaluate the ultrasound biomicroscopy images of 13 patients (13 eyes) including involved eyes imaged prior to the malignant glaucoma onset or eligible fellow eyes. A narrow angle with or without iridotrabecular contact was found in all eyes. A large and/or anteriorly positioned ciliary body associated with an iris root angulating forward and centrally, revealing a plateau iris configuration, was noticed in 85% (11/13) of these eyes. CONCLUSION: Identification of plateau iris configuration by ultrasound biomicroscopy should be considered as a possible predictor of post-operative malignant glaucoma development.

Purpose: To determine whether glaucoma subtype is an independent risk factor for visual field (VF) progression. Methods: We reviewed the charts of glaucoma suspects and glaucoma patients seen in a referral practice between 1999 and 2009. Automated pointwise linear regression analysis determined the rates of VF change. A progression endpoint was determined when two or more adjacent test locations in the same hemifield showed a threshold sensitivity decline at a rate of >/=1.0 dB/year with p < 0.01. Results: We included 841 eyes (841 patients; mean age, 64.1 +/- 12.6 years; mean number of VF tests, 10.8 +/- 2.8; mean follow-up, 6.4 +/- 1.7 years). The glaucomatous group consisted of angle-closure glaucoma (76 eyes), juvenile primary open-angle glaucoma (37 eyes), normal-tension glaucoma (81 eyes), pigmentary glaucoma (34 eyes), primary open-angle glaucoma (275 eyes) and exfoliative glaucoma (XFG, 84 eyes). Normal-tension glaucoma eyes were more likely to present with beta-zone parapapillary atrophy and disc haemorrhage (p < 0.01). Exfoliative glaucoma eyes had the fastest rates of global VF change (-0.65 dB/year), as well as the highest mean, fluctuation, and peak intraocular pressure during follow-up (16.5, 3.0 and 22.0 mmHg, respectively) and reached a progression endpoint more frequently (40%). After adjusting for all covariates, including the glaucoma phenotype, there was no difference among groups regarding global rates of VF change and the risk of reaching a progression endpoint. Conclusions: Despite different clinical features, epidemiology and genetics, glaucoma phenotype is not an independent risk factor for VF progression. Rather, variations in well-known, reported risk factors remain important disease parameters that affect progression

PURPOSE: To evaluate the ability of the short-duration transient visual evoked potential (SD-tVEP) to discriminate between healthy eyes and eyes with early to advanced glaucomatous visual field loss. METHODS: We tested 30 eyes of 30 healthy controls and 45 eyes of 35 glaucoma patients. Normal eyes had 20/30 or better visual acuity and normal 24-2 Swedish interactive thresholding algorithm (SITA) Standard visual fields. Glaucoma was staged as mild (mean deviation, MD > -6.0 dB), moderate (MD between -6.0 and -12.0 dB), and severe (MD < -12.0 dB). There were 15 eyes in each group. SD-tVEPs were recorded using the Diopsys NOVA-LX System. Each eye was stimulated with a low (Lc) and a high (Hc) Michelson contrast checkerboard pattern. Each test resulted in an Lc and an Hc SD-tVEP response. Each response was evaluated for overall waveform quality, P100 latency, and P100 amplitude referenced to the N75. The sensitivity, specificity, negative predictor value (NPV), and positive predictor value (PPV) were calculated. RESULTS: Lc latency showed the highest accuracy for discrimination using receiver operating characteristic curves for high and low contrast parameters. The analysis for all subjects resulted in a 91.1% sensitivity, 93.3% specificity, 95.3% PPV, and an 87.5% NPV. Evaluating the mean Lc latency of the mild, moderate, and severe glaucoma patients against controls showed discrimination consistent with the glaucoma severity. CONCLUSIONS: Short-duration transient VEP objectively identified decreased visual function and discriminated between healthy and glaucomatous eyes, and also showed good differentiation between healthy eyes and those with early visual field loss. VEP may be useful for early diagnosis of glaucoma.

PURPOSE:: To report on the usefulness of combined Baerveldt glaucoma implantation (BGI) and scleral buckling surgery for patients with glaucoma requiring a scleral buckle for retinal detachment repair. METHODS:: Retrospective, consecutive, noncomparative, and interventional case series of 30 eyes (30 patients) that underwent simultaneous scleral buckle and BGI surgery, using a staged (group 1, n=21 patients) or nonstaged (group 2, n=9 patients) approach to BGI implantation. Successful intraocular pressure (IOP) control was defined as 6 mm Hg</=IOP</=18 mm Hg. RESULTS:: Although not statistically significant, mean best corrected visual acuity (LogMAR) improved from 2.0 before surgery to 1.7 after surgery (P=0.13) with a mean follow-up of 27.7 months. Of the 21 patients in group 1, only 13 (62%) required second-stage tube insertion at a mean of 7.0+/-8.0 months (range, 1 to 24 mo) postoperatively. For these eyes combined with group 2 eyes, mean IOP was reduced from 31.1+/-10.8 to 12.7+/-6.0 mm Hg (P<0.0001), and the mean number of glaucoma medications was reduced from 2.9+/-1.4 to 1.2+/-1.3 (P<0.001). Life table rates of successful IOP control were 90% and 80% at 12 and 24 months, respectively. CONCLUSIONS:: Combined scleral buckle and BGI is an effective technique for managing coexisting glaucoma and retinal detachment and provides the clinician with a useful surgical option while minimizing surgical risk

Purpose: To investigate the relationship between optic disc progression and rates of visual field (VF) change in patients with treated glaucoma. Methods: Glaucoma patients with repeatable VF loss, >/=8 SITA-Standard 24-2 VF tests and good quality optic disc stereophotographs evaluated over a 10-year period were included. Optic disc photographs were reviewed for signs of glaucoma progression (neuroretinal rim change, widening of retinal nerve fibre layer defect, disc haemorrhage and enlargement of beta-zone parapapillary atrophy) by two glaucoma specialists masked to their temporal sequence. Disagreements were adjudicated by a third grader. VF progression was evaluated using automated pointwise linear regression (PLR) and defined as at least two adjacent test points progressing >1.0 dB/year at p < 0.01. VF progression outcomes were compared with photograph review results. Results: Three-hundred and eighty nine eyes (389 patients; mean age 64.9 +/- 13.0 years; mean baseline MD, -7.1 +/- 5.1 dB) were included. Most patients had primary open angle glaucoma (54%). Eighty-two eyes (21%) had confirmed optic disc progression and 115 eyes (29%) met the VF PLR criteria. Eyes with documented optic disc progression had more rapid rates of VF change (-0.66 +/- 0.7 versus -0.36 +/- 0.7 dB/year, p < 0.01) and met the VF PLR endpoint more often (univariate OR = 1.85, p = 0.02; multivariate OR = 1.78, p = 0.03) than eyes without optic disc progression. There was moderate spatial consistency between the location of the optic disc progression and the hemifield with more rapid progression (81%, kappa = 0.40). Conclusions: Treated glaucomatous eyes with documented optic disc progression are at increased risk of diminished visual function over time and may require more aggressive therapy to prevent future vision loss. Among the indicators of structural progression, disc haemorrhage was the single most significant predictor for VF deterioration.

PURPOSE: We sought to determine whether filtering surgery, even when only partially successful, delays or slows visual field (VF) progression. METHODS: The records of all patients seen in a glaucoma referral practice from 1999 to 2009 were reviewed. Group A comprised eyes with >/=5 VFs before surgery and group B comprised eyes with >/=5 VFs after surgery. Eyes in group B were further divided into those requiring postoperative topical ocular hypotensive therapy (group B-2) and those that did not (group B-1). Automated pointwise linear regression was used to determine global rates (dB/y) of change and progression endpoints. A progression endpoint was determined when 2 or more adjacent test locations in the same hemifield showed a threshold sensitivity decline at a rate of >/=1.0 dB/year with P<0.01. RESULTS: A total of 206 treated eyes (206 patients; mean age, 63.8+/-13.0 y; 11.3+/-3.1 VFs; 6.4+/-1.8 y follow-up) were included. Mean global VF progression rates in group A (-0.86+/-0.8 dB/y) were faster than those in group B (-0.49+/-0.9 dB/y, P<0.01). Group A also had a greater risk of reaching a progression endpoint compared with group B (odds ratio=2.41, P<0.01). Groups B-1 and B-2 had different follow-up intraocular pressure means (12.7+/-3.7 vs. 15.5+/-2.7 mm Hg, respectively; P<0.01) and peaks (19.4+/-5.2 vs. 21.2+/-4.2 mm Hg; P=0.08). The velocity of VF progression was similar for groups B-1 and B-2 (-0.40+/-0.6 vs. -0.58+/-1.1 dB/y; P=0.22) and there was no significant difference between the 2 groups regarding the risk of reaching a progression endpoint (odds ratio=0.83, P=0.62). CONCLUSIONS: Filtering surgery reduces the rate of disease progression and this effect persists even if adjunctive glaucoma medical therapy is required

PURPOSE: To investigate the correlation between structural and functional damage in patients with asymmetric glaucoma using a newly developed short duration transient visual evoked potential (SD-tVEP) device. METHODS: Twenty-five patients with visual acuity >/=20/30 and asymmetric visual field (VF) loss [inter-eye difference in mean deviation index (MD) of at least 3 dB] were enrolled. Patients underwent optical coherence tomography (OCT) for macular thickness measurement, scanning laser polarimetry with variable corneal compensation for retinal nerve fiber layer measurement, and SD-tVEP (10% and 85% Michelson contrast, acquisition time of 20 s) in both eyes within 2 months. We correlated VF MD and structural test results with SD-tVEP P100 latency and Delta Amplitude (N75-P100). RESULTS: Using 10% contrast, there was a significant difference in SD-tVEP latency and amplitude between eyes with better and worse VF MD (P<0.001). MD correlated significantly with both SD-tVEP parameters (r>0.33, P</=0.01). When using 85% contrast, SD-tVEP amplitude differed between eyes (P=0.01) and MD values correlated significantly with amplitude results (r=0.32, P=0.01), but not with latency (P=0.46). In eyes with more advanced VF loss, there was a positive and significant correlation between SD-tVEP amplitude (85% contrast) and macular thickness on OCT (r=0.47, P=0.01), but not with retinal nerve fiber layer measured with polarimetry (P=0.26). CONCLUSIONS: In cases of asymmetric glaucoma, SD-tVEP results correlate significantly with the level of VF damage as measured by MD. In the eyes with more advanced VF loss, reduced SD-tVEP amplitude was associated with decreased macular thickness on OCT. These findings suggest that SD-tVEP may be a fast and objective method to assess or screen for functional damage in glaucomatous eyes

Background: To determine if optic disc phenotype is correlated with the rate of glaucomatous visual field progression. Design: Retrospective cohort. Participants or Samples: Treated glaucoma patients. Methods: The optic disc stereophotographs of glaucoma patients were reviewed by two investigators masked to all clinical and perimetric data. Each disc was classified as focal ischaemic, myopic, senile sclerotic and generalized enlargement. Visual field progression (defined as at least two adjacent test points in the same hemifield progressing by more than 1.0 dB/year at P < 0.01) was evaluated using automated pointwise linear regression. Main Outcome Measures: Association between optic disc phenotypes and other clinical variables and rates of visual field progression. Results: 264 optic disc stereophotographs (127 generalized enlargement, 41 focal ischaemic, 54 myopic and 42 senile sclerotic) were evaluated. In the univariate analyses, it was found that patients with senile sclerotic discs were older (p = 0.002) and those with generalized enlargement had better baseline visual field mean deviation (p < 0.001) and higher intraocular pressure (p = 0.006) compared with the other groups. More disc haemorrhages were detected in the focal ischaemic and senile sclerotic groups (p = 0.010). After adjusting for other risk factors (intraocular pressure, age, central corneal thickness, disc haemorrhage), there were no differences among groups regarding the risk (p = 0.58) and velocity (p = 0.21) of visual field progression. Conclusions: Visual field progression was similar among the four optic disc phenotypes in treated glaucoma after adjusting for other known risk factors. The division of disc appearance into clinical phenotypes does not appear to provide independent information regarding the risk of progression in clinical practice.

OBJECTIVES: To assess focal lamina cribrosa (LC) defects in glaucoma using enhanced depth imaging optical coherence tomography and to investigate their spatial relationships with neuroretinal rim and visual field loss. METHODS: Serial horizontal and vertical enhanced depth imaging optical coherence tomographic images of the optic nerve head were obtained from healthy subjects and those with glaucoma. Focal LC defects defined as anterior laminar surface irregularity (diameter, >100 mum; depth, >30 mum) that violates the normal smooth curvilinear contour were investigated regarding their configurations and locations. Spatial consistency was evaluated among focal LC defects, neuroretinal rim thinning/notching, and visual field defects. RESULTS: Forty-six healthy subjects (92 eyes) and 31 subjects with glaucoma (45 eyes) were included. Ninety-eight focal LC defects representing various patterns and severity of laminar tissue loss were found in 34 eyes with glaucoma vs none in the healthy eyes. Seven of 11 eyes with glaucoma with no visible focal LC defect had a deeply excavated optic disc with poor LC visibility. Eleven focal LC defects presented clinically as an acquired pit of the optic nerve, and the others as neuroretinal rim thinning/notching. Focal LC defects preferably occurred in the inferior/inferotemporal far periphery of the LC including its insertion. Eyes with focal LC defects limited to the inferior half of the optic disc had greater sensitivity loss in the superior visual hemifield and vice versa. CONCLUSIONS: Mechanisms of LC deformation in glaucoma include focal loss of laminar beams, which may cause an acquired pit of the optic nerve in extreme cases. Focal LC defects occur in tandem with neuroretinal rim and visual field loss