Faculty Bibliography

AIM: We investigated the correlation between central corneal thickness (CCT) and corneal hysteresis (CH) and their relationship with the rate of visual field (VF) change. METHODS: Glaucoma patients who underwent complete ophthalmic examination and tonometry using both the Goldmann applanation tonometer and the Ocular Response Analyzer were prospectively enrolled. Only eyes with >/=5 SITA Standard 24-2 VF tests were included. Automated pointwise linear regression analysis was used to determine VF progression. One hundred fifty-three eyes (153 patients; mean age, 61.3+/-14.0 y; mean number of VF, 8.5+/-3.4; mean follow-up time, 5.3+/-2.0 y) met the enrollment criteria. RESULTS: The mean global rate of VF change was -0.34+/-0.7 dB/y. Twenty-five eyes (16%) reached a progression endpoint. Progressing eyes had lower CCT (525.0+/-34.2 vs 542.3+/-38.5 mum, P=0.04) and lower CH (7.5+/-1.4 vs 9.0+/-1.8 mm Hg, P<0.01) compared with nonprogressing eyes. CH and CCT correlated significantly (r=0.33, P<0.01). By multivariate analysis, peak intraocular pressure [odds ratio (OR)=1.13 per mm Hg higher, P<0.01], age (OR=1.57 per decade older, P=0.03), and CH (OR=1.55 per mm Hg lower, P<0.01) remained statistically significant. CONCLUSIONS: Corneal biomechanical and physical properties, such as CH and CCT, are highly correlated and associated with VF progression. As CH may describe corneal properties more completely than thickness alone, it may be a parameter that is better associated with progression

Purpose:To assess the general morphology and position of the lamina cribrosa (LC) in normal subjects using enhanced depth imaging optical coherence tomography (EDI OCT).Methods:Serial horizontal and vertical B-scans of the optic nerve head (interval between images: approximately 30 mum) were prospectively obtained using EDI OCT for both eyes of each normal subject. After delineation of the anterior laminar surface, mean and maximum LC depths were measured in 11 equally spaced horizontal B-scans, and the depth of the anterior LC insertion was measured at 32 points along its circumference (reference plane: Bruch's membrane edges) for one randomly selected eye of each subject. 3-dimensional (3D) images of the anterior laminar surface and peripapillary sclera were reconstructed from serial horizontal EDI OCT B-scans to assess the 3D morphology of the anterior laminar surface.Results:Among the 61 eyes (61 subjects) enrolled, 31 were excluded because of poor LC image quality and 30 were included for analysis (mean age: 40+/-18 [range, 21 to 78] years). Both mean and maximum LC depth profiles showed an elevation in the central area and a depression in the superior and inferior mid-periphery of the LC. The anterior LC insertion was more posteriorly located in the superior and inferior than the nasal and temporal regions. 3D LC images showed a bow tie-shaped horizontal central ridge of the LC.Conclusions:The LC has a central ridge ranging from the temporal to the nasal insertion areas, and inserts more posteriorly in the superior and inferior than in the nasal and temporal regions. Further investigation is needed to elucidate the significance of these findings in the pathophysiology of glaucoma

PURPOSE: To evaluate the relationship between beta-zone parapapillary atrophy (betaPPA) and corneal hysteresis (CH) in patients with glaucoma. DESIGN: Prospective, cross-sectional study. METHODS: Glaucoma patients aged 18 to 90 years with disc photographs within 12 months of the study visit were consecutively enrolled. Exclusion criteria included ocular surgery other than clear corneal phacoemulsification, myopia >6 diopters, contact lens use, and corneal abnormality. CH was measured using the Ocular Response Analyzer (ORA). Disc photographs were evaluated in a masked fashion for betaPPA. RESULTS: We enrolled 99 patients (mean age 67.6 years; 45 men, 54 women). Univariate analysis showed no significant difference in CH between eyes with and without betaPPA (8.72 +/- 0.23 vs 8.15 +/- 0.27 mm Hg, P = .11). There were no differences in corneal resistance factor (CRF) (P = .47), central corneal thickness (CCT) (P = .11), ORA wave score (P = .23), age (P = .23), sex (P = .40), IOP (P = .86), or visual field mean deviation (VFMD) (P = .45). Eyes with betaPPA were more myopic (-1.49 +/- 0.27 vs -0.22 +/- 0.31 diopters, P = .003). Multivariate analysis showed no significant difference in CH between eyes with and without betaPPA (P = .38). Eyes with asymmetric betaPPA also showed no significant difference in CH (8.97 +/- 0.22 vs 9.10 +/- 0.22 mm Hg, P = .69). CONCLUSIONS: We found no significant differences in CH between eyes with and without betaPPA or between fellow eyes with asymmetric betaPPA

OBJECTIVE: To assess the usefulness of enhanced depth imaging (EDI) optical coherence tomography (OCT) for evaluating deep structures of the optic nerve complex (ONC; optic nerve head and peripapillary structures) in glaucoma. DESIGN: Prospective, observational study. PARTICIPANTS: Seventy-three established glaucoma patients (139 eyes) with a range of glaucomatous damage. METHODS: Serial horizontal and vertical EDI OCT images of the ONC were obtained from both eyes of each participant. Deep ONC structures, including the lamina cribrosa (LC), short posterior ciliary artery (SPCA), central retinal artery (CRA), central retinal vein (CRV), peripapillary choroid and sclera, and subarachnoid space around the optic nerve, were investigated for their visibility and morphologic features. MAIN OUTCOME MEASURES: Deep ONC structures identified in EDI OCT images. RESULTS: Visual field mean deviation of 139 included eyes was -11.8+/-8.6 dB (range, -28.70 to -2.01 dB). The anterior laminar surface was identified in all eyes in the central laminar area and in 91 (65%) eyes in the periphery beneath the neuroretinal and scleral rims or vascular structures. The LC pores with various shapes and sizes were visualized in 106 (76%) eyes, mainly in the central and temporal areas of the LC. Localized LC lesions seen on optic disc photographs were identified as focal LC defects (partial loss of LC tissue) in the EDI OCT images. The locations of the CRA and CRV were identified in all eyes. In the LC, the CRA maintained a straight shape with a consistent caliber, but the CRV (and tributaries) assumed a more irregular shape. The SPCAs, their branches through the emissary canals in the sclera, or both were visualized in 120 (86%) eyes. The subarachnoid space around the optic nerve was identified with varying degrees of clarity in 25 eyes (18%): 17 had high myopia and extensive parapapillary atrophy. Intrachoroidal cavitation or choroidal schisis, which had been unrecognized clinically, was identified in 2 eyes (1%) with high myopia. CONCLUSIONS: Enhanced depth imaging OCT was able to visualize a wide variety of deep ONC structures in glaucoma patients and may be helpful in detecting, conceptualizing, and understanding basic and complicated in vivo anatomic and pathologic features of the ONC in glaucoma. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references

PURPOSE: To determine if visual field (VF) progression occurs most rapidly in the region of largest beta-zone parapapillary atrophy (PPA). DESIGN: Retrospective cohort. PARTICIPANTS: One hundred twenty-five patients from the New York Glaucoma Progression Study with both beta-zone PPA and VF progression. METHODS: Treated open-angle glaucoma patients with 8 or more Swedish Interactive Threshold Algorithm Standard 24-2 VFs (Humphrey Field Analyzer II; Carl Zeiss Meditec, Inc., Dublin, CA) in either eye were identified. Eyes with optic disc photographs, beta-zone PPA, less than 6 diopters myopia, and VF progression were studied. Visual field progression was defined using trend analysis as the presence of at least 2 adjacent progressing points in the same hemifield using standard pointwise linear regression (PLR) criteria. MAIN OUTCOME MEASURES: The correlation between beta-zone PPA and location of most rapid future VF progression. RESULTS: One hundred twenty-five eyes (125 patients; mean age, 71.9+/-12.3 years; 58% women; 75% European descent) with beta-zone PPA and VF progression were enrolled. The mean follow-up was 6.8+/-1.7 years and the mean number of VFs was 12.5+/-3.6. Ninety-three patients (74%) had more beta-zone PPA inferiorly and 32 patients (26%) had more beta-zone PPA superiorly. The fastest VF progression occurred in the superior hemifield in 77 patients (62%) and in the inferior hemifield in 48 (38%) patients. Patients with superior VF progression had a superior localized mean rate of progression of -1.57+/-1.7 dB/year, and patients with inferior VF progression had an inferior localized mean rate of -0.94+/-1.4 dB/year (P = 0.012). The mean number of points reaching the predefined PLR end points was 5.6+/-7.5 for the superior VF hemifield and 3.0+/-4.9 for the inferior hemifield (P = 0.006). The hemifield with more points reaching PLR progression end points, with fastest average velocity of progression, or both was spatially consistent with the location of largest beta-zone PPA in 89 (71%) patients (P = 0.0001, Fisher exact test; kappa = 0.35; 95% confidence interval, 0.17-0.53). CONCLUSIONS: In treated glaucoma patients with beta-zone PPA and VF progression, the location of largest beta-zone PPA typically correlates spatially with the region of the most rapid future VF progression. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article

This study examined effects of uncorrected refractive errors (RE) in a short-duration transient visual evoked potential (SD t-VEP) system and investigated their role for objective measurement of RE. Refractive errors were induced by means of trial lenses in 35 emmetropic subjects. A synchronized single-channel EEG was recorded for emmetropia, and each simulated refractive state to generate 21 VEP responses for each subject. P100 amplitude (N75 trough to P100 peak) and latency were identified by an automated post-signal processing algorithm. Induced hypermetropia and myopia correlated strongly with both P100 amplitude and latency. To minimize the effect of baseline shift and waveform fluctuations, a VEP scoring system, based on software-derived P100 latency, amplitude and waveform quality, was used to estimate the RE. Using the VEP scores, a single VEP response had a high sensitivity and specificity for discerning emmetropia, small RE (<2 diopter) within a 2 diopter range and large RE (2-14 diopter) within a 4 diopter range. The VEP scoring system has a potential for objective screening of RE and for a more accurate 3-step objective refraction

OBJECTIVE: To assess risk factors for an initial parafoveal scotoma (IPFS) compared with an initial nasal step (INS) in glaucoma. DESIGN: Retrospective, observational study. PARTICIPANTS: Sixty-nine patients with glaucoma with an isolated IPFS and 53 patients with an isolated INS. METHODS: On the basis of 2 reliable, consistent 24-2 Swedish interactive threshold algorithm standard visual fields (VFs), 2 groups of patients with glaucoma were studied: those with an IPFS in 1 hemifield (>/=3 adjacent points with P<5% within the central 10 degrees of fixation, >/=1 point with P<1% lying at the innermost paracentral points, and no VF abnormality outside the central 10 degrees) and those with an INS in 1 hemifield (>/=3 adjacent points with P<5% in the nasal periphery outside 10 degrees of fixation, the nasal-most point with P<1%, and no VF abnormality within the central 10 degrees). Clinical characteristics and systemic factors were recorded from charts and compared between the 2 groups. MAIN OUTCOME MEASURES: Maximum untreated intraocular pressure (IOP), disc hemorrhage (DH) detection during follow-up, systemic risk factors, and VF mean deviation (MD) and pattern standard deviation (PSD). RESULTS: Maximum untreated IOP (21.6+/-4.5 vs. 28.3+/-9.6 mmHg; P<0.001) was significantly lower, and frequency of DH detection (44% vs. 17%; P=0.001) and systemic risk factors (hypotension, migraine, Raynaud's phenomenon, and sleep apnea; 16%, 23%, 24%, and 9% vs. 0%, 4%, 9%, and 0%; P=0.001, 0.002, 0.025, and 0.030, respectively) were significantly higher in patients with an IPFS than in patients with an INS. There were no significant differences in age, gender, family history of glaucoma, refractive error, central corneal thickness, and disc area between the 2 groups (all P>0.1). Mean deviation was similar between the 2 groups (P=0.346), but PSD was significantly greater in the IPFS group than in the INS group (P=0.043). CONCLUSIONS: Eyes with an IPFS differ from those with an INS. These findings may help clinicians identify patients at higher risk of early central field loss. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references

OBJECTIVE: To determine intraocular pressure (IOP)-dependent and IOP-independent variables associated with visual field (VF) progression in treated glaucoma. DESIGN: Retrospective cohort of the Glaucoma Progression Study. METHODS: Consecutive, treated glaucoma patients with repeatable VF loss who had 8 or more VF examinations of either eye, using the Swedish Interactive Threshold Algorithm (24-2 SITA-Standard, Humphrey Field Analyzer II; Carl Zeiss Meditec, Inc, Dublin, California), during the period between January 1999 and September 2009 were included. Visual field progression was evaluated using automated pointwise linear regression. Evaluated data included age, sex, race, central corneal thickness, baseline VF mean deviation, mean follow-up IOP, peak IOP, IOP fluctuation, a detected disc hemorrhage, and presence of beta-zone parapapillary atrophy. RESULTS: We selected 587 eyes of 587 patients (mean [SD] age, 64.9 [13.0] years). The mean (SD) number of VFs was 11.1 (3.0), spanning a mean (SD) of 6.4 (1.7) years. In the univariable model, older age (odds ratio [OR], 1.19 per decade; P = .01), baseline diagnosis of exfoliation syndrome (OR, 1.79; P = .01), decreased central corneal thickness (OR, 1.38 per 40 mum thinner; P < .01), a detected disc hemorrhage (OR, 2.31; P < .01), presence of beta-zone parapapillary atrophy (OR, 2.17; P < .01), and all IOP parameters (mean follow-up, peak, and fluctuation; P < .01) were associated with increased risk of VF progression. In the multivariable model, peak IOP (OR, 1.13; P < .01), thinner central corneal thickness (OR, 1.45 per 40 mum thinner; P < .01), a detected disc hemorrhage (OR, 2.59; P < .01), and presence of beta-zone parapapillary atrophy (OR, 2.38; P < .01) were associated with VF progression. CONCLUSIONS: IOP-dependent and IOP-independent risk factors affect disease progression in treated glaucoma. Peak IOP is a better predictor of progression than is IOP mean or fluctuation

PurposeTo evaluate the relationships between baseline visual field (VF) mean deviation (MD) and subsequent progression in treated glaucoma.MethodsRecords of patients seen in a glaucoma practice between 1999 and 2009 were reviewed. Patients with glaucomatous optic neuropathy, baseline VF damage, and >/=8 SITA-standard 24-2 VF were included. Patients were divided into tertiles based upon baseline MD. Automated pointwise linear regression determined global and localized rates (decibels (dB) per year) of change. Progression was defined when two or more adjacent test locations in the same hemifield showed a sensitivity decline at a rate of >1.0 dB per year, P<0.01.ResultsFor mild, moderate, and severe groups, progression was noted in 29.5, 31.2, and 26.0% of eyes (P=0.50) and global rates of VF change of progressing eyes were -1.3+/-1.2, -1.01+/-0.7, and -0.9+/-0.5 dB/year (P=0.09, analysis of variance). Within these groups, intraocular pressure (IOP) in stable vs progressing eyes were 15.5+/-3.3 vs 17.0+/-3.1 (P<0.01), 15.4+/-3.3 vs 15.9+/-2.5 (P=0.28), and 14.0+/-2.8 vs 14.8+/-2.3 mm Hg (P=0.07). More glaucoma filtering surgeries were performed in eyes with worse MD. There was no significant difference between groups regarding their risk of progression in both univariate (P=0.50) and multivariate (P=0.26) analyses adjusting for differences in follow-up IOP.ConclusionsAfter correcting for differences in IOP in treated glaucoma patients, we did not find a relationship between the rate of VF change (dB per year) and the severity of the baseline VF MD. This finding may have been due to more aggressive IOP lowering in eyes with more severe disease. Eyes with lower IOP progressed less frequently across the spectrum of VF loss

BACKGROUND AND OBJECTIVE: To determine the safety and efficacy of amniotic membrane graft in glaucoma drainage device surgery. PATIENTS AND METHODS: Institutional retrospective case series of 44 patients undergoing glaucoma drainage device implantation with use of 300-mum thick amniotic membrane as a patch graft. Endpoints assessed were tube exposure, graft thinning, graft clarity, graft-related infection, and inflammation. RESULTS: A total of 41 (93%) eyes had an uneventful course over a mean follow-up of 22 +/- 3 months (range: 17 to 28 months). Tube exposure and hypotony each occurred in one eye and were successfully treated with a tube revision using double pericardial and amniotic membrane patch graft. The translucency of amniotic membrane graft enabled good visualization of the occluding suture when performing laser suture lysis in 16 eyes. Sequential anterior segment optical coherence tomography showed stable amniotic membrane graft thickness with a change from low to moderate reflectivity in the subconjunctival-graft bilayer. CONCLUSION: Amniotic membrane graft offers good tectonic support and allows direct visualization of the underlying tube