Farzaneh Naghizadeh

Detection of early glaucomatous progression with different parameters of the RTVue optical coherence tomograph

Purpose:To investigate the ability of different parameters of the RTVue-100 Fourier-domain optical coherence tomograph (RTVue-OCT) to detect early glaucomatous progression. Methods:One eye of 17 healthy and 51 perimetric glaucoma patients was imaged prospectively at 6-month intervals for 1.5 to 3 years. Progression was determined by Octopus normal G2 visual field progression criteria. Results:Ten of the 51 glaucoma eyes progressed based on visual field criteria. Median visual field mean defect change was −0.300 dB/y for the controls, −0.120 dB/y for all glaucoma eyes (P=0.461 vs. controls), and 1.231 dB/y for the 10 functionally progressing glaucoma eyes (P<0.001 vs. controls). Ganglion cell complex (GCC), focal loss volume, and GCC global loss volume showed significantly faster rate of progression in the glaucoma group than in controls (P=0.004 and P=0.001, respectively). No optic nerve head, retinal nerve fiber layer thickness, and average GCC parameter separated the rate of progression between the groups. Conclusions:Early structural progression of glaucoma may be better detected with pattern-based GCC parameters of the RTVue-OCT than with the optic nerve head, retinal nerve fiber layer thickness or average GCC parameters of the same instrument.

Structure-function relationship between the octopus perimeter cluster mean sensitivity and sector retinal nerve fiber layer thickness measured with the RTVue optical coherence tomography and scanning laser polarimetry

Purpose:To determine structure-function relationship between each of 16 Octopus perimeter G2 program clusters and the corresponding 16 peripapillary sector retinal nerve fiber layer thickness (RNFLT) values measured with the RTVue-100 Fourier-domain optical coherence tomography (RTVue OCT) and scanning laser polarimetry with variable corneal compensation (GDx-VCC) and enhanced corneal compensation (GDx-ECC) corneal compensation. Methods:One eye of 110 white patients (15 healthy, 20 ocular hypertensive, and 75 glaucoma eyes) were investigated. The Akaike information criterion and the F test were used to identify the best fitting model. Results:Parabolic relationship with logarithmic cluster mean sensitivity and linear sector RNFLT values provided the best fit. For RTVue OCT, significant (P<0.0001) coefficients of determination (R2) were found for all 16 RNFLT sectors. The R2 values were highest for the temporal, superotemporal, and inferotemporal RNFLT sectors (0.4483 to 0.5186). For GDx-VCC/ECC, significant (P<0.01) parabolic relationship was seen for all but the temporal and nasal RNFLT sectors. The overall highest R2 value (0.6943) was found for a superotemporal RNFLT sector with GDx-ECC. For some RNFLT sectors, the goodness of fit differed significantly between the imaging methods. Structure-function relationship was similar for the total population and the glaucoma subgroup, whereas no relationship (P>0.05) was found for the control eyes. Conclusions:Mean sensitivity of the Octopus visual field clusters showed significant parabolic relationship with the corresponding peripapillary RNFLT sectors. The relationship was more general with the RTVue OCT than GDx-VCC or GDx-ECC. The results show that visual field clusters of the Octopus G program can be applied for detailed structure-function research.

Detection of early glaucomatous progression with octopus cluster trend analysis.

Purpose:To compare the ability of Corrected Cluster Trend Analysis (CCTA) and Cluster Trend Analysis (CTA) with event analysis of Octopus visual field series to detect early glaucomatous progression. Methods:One eye of 15 healthy, 19 ocular hypertensive, 20 preperimetric, and 51 perimetric glaucoma (PG) patients were investigated with Octopus normal G2 test at 6-month intervals for 1.5 to 3 years. Progression was defined with significant worsening in any of the 10 Octopus clusters with CCTA, and event analysis criteria, respectively. Results:With event analysis, 9 PG eyes showed localized progression and 1 diffuse mean defect (MD) worsening. With CCTA, progression was indicated in 1 normal, 1 ocular hypertensive, and 1 preperimetric glaucoma eyes due to vitreous floaters, and 28 PG eyes including all 9 eyes with localized progression with event analysis. The locations of CCTA progression matched those found with event analysis in all 9 cases. In 17 of the remaining 19 eyes, progressing clusters matched the locations that were suspicious but not definitive for progression with event analysis. In the eye with diffuse MD worsening, CTA found significant progression for 7 clusters. For global MD progression rate, eyes worsened with CCTA only did not differ from the stable eyes but had significantly smaller progression rates than the eyes progressed with event analysis (P=0.0002). Conclusions:In PG, Octopus CCTA and CTA are clinically useful to identify early progression and areas suspicious for early progression. However, in some eyes with no glaucomatous visual field damage, vitreous floaters may cause progression artifacts.

Influence of a new software version of the RTVue-100 optical coherence tomograph on ganglion cell complex segmentation in various forms of age-related macular degeneration

Purpose:Previously, we have shown that age-related macular degeneration (AMD) influences glaucoma classification with the ganglion cell complex (GCC) parameters of the RTVue-100 optical coherence tomograph (RTVue-OCT) in nonglaucomatous eyes. Now, we reevaluated the influence of AMD on GCC image segmentation and classification for glaucoma on the same eyes, using a new version of the software. Methods:GCC images of nonglaucomatous eyes [30 healthy, 19 with early/intermediate AMD, 16 with subfoveal choroidal neovascularization (CNV), and 19 after intravitreal antiangiogenic treatment of CNV, CNV-anti-VEGF] were reanalyzed with software versions 6.3 (the currently available version) and 6.12 (a version not yet commercially released). Results:Global loss volume (GLV) was significantly reduced with version 6.12 in all groups (P⩽0.0416). Segmentation errors were seen in 2 versus 0 of the normal eyes (P=0.500), 8 versus 0 of the early/intermediate AMD eyes (P=0.0312), 16 versus 6 of the CNV eyes (P=0.0080), and 18 versus 3 of the CNV-anti-VEGF eyes (P=0.0004) with software versions 6.3 and 6.12, respectively. For focal loss volume the distribution of the classification results differed significantly between the software versions in the CNV and CNV-anti-VEGF groups (P=0.0312 and 0.0160, respectively). For both groups more eyes were classified as “within normal limits,” and less as “outside normal limits” with software version 6.12 than with version 6.3. Conclusions:For nonglaucomatous AMD eyes the frequency of GCC segmentation errors was significantly reduced, GLV was significantly lower (more normal), and the classification for glaucoma was more correct with software version 6.12 than with version 6.3.

Comparison of long-term variability of retinal nerve fiber layer measurements made with the RTVue OCT and scanning laser polarimetry

Purpose. To compare long-term variability of retinal nerve fiber layer thickness (RNFLT) measurements made with the RTVue-100 Fourier-domain optical coherence tomograph (RTVue-OCT) and scanning laser polarimetry with variable (GDx-VCC) and enhanced (GDx-ECC) corneal compensation. Methods. One eye each of 110 Caucasian patients (17 healthy, 20 ocular hypertensive, 22 preperimetric, and 51 perimetric glaucoma eyes, of which 10 showed visual field progression) were imaged prospectively at 6-month intervals for 1.5 to 3 years. Results. Median change of Octopus visual field mean defect was −0.300 dB/y for the controls, −0.120 dB/y for perimetric glaucoma group, and 1.231 dB/y for the 10 functionally progressing perimetric glaucoma eyes. Relative (%) variance of all RNFLT parameters measured with RTVue-OCT was significantly (p<<0.001) smaller than that with both of the GDx methods. Relative RNFLT progression slopes (% change/y) did not differ significantly between the methods. Relative variance of the RNFLT parameters did not differ between the control and perimetric glaucoma group with RTVue-OCT, but for most parameters it was consistently higher for perimetric glaucoma with both GDx methods (p≤0.01). Relative RNFLT progression slopes, however, did not separate the control and perimetric glaucoma eyes with either method. Conclusions. Long-term RNFLT measurements are less variable with the RTVue-OCT than with GDx-VCC and GDx-ECC. Long-term measurement variability is higher in perimetric glaucoma than in healthy eyes with both GDx methods, but no similar between-group difference is seen with RTvue-OCT. None of the tested methods separated the rate of progression between healthy and well-controlled perimetric glaucoma eyes in 1.5 to 3 years follow-up.

Evaluation of a new software version of the RTVue optical coherence tomograph for image segmentation and detection of glaucoma in high myopia

Purpose:To compare the current (6.3) and a novel software version (6.12) of the RTVue-100 optical coherence tomograph (RTVue-OCT) for ganglion cell complex (GCC) and retinal nerve fiber layer thickness (RNFLT) image segmentation and detection of glaucoma in high myopia. Materials and Methods:RNFLT and GCC scans were acquired with software version 6.3 of the RTVue-OCT on 51 highly myopic eyes (spherical refractive error ⩽−6.0 D) of 51 patients, and were analyzed with both the software versions. Twenty-two eyes were nonglaucomatous, 13 were ocular hypertensive and 16 eyes had glaucoma. Results:No difference was seen for any RNFLT, and average GCC parameter between the software versions (paired t test, P≥0.084). Global loss volume was significantly lower (more normal) with version 6.12 than with version 6.3 (Wilcoxon signed-rank test, P<0.001). The percentage agreement (&kgr;) between the clinical (normal and ocular hypertensive vs. glaucoma) and the software-provided classifications (normal and borderline vs. outside normal limits) were 0.3219 and 0.4442 for average RNFLT, and 0.2926 and 0.4977 for average GCC with versions 1 and 2, respectively (McNemar symmetry test, P≥0.289). No difference in average RNFLT and GCC classification (McNemar symmetry test, P≥0.727) and the number of eyes with at least 1 segmentation error (P≥0.109) was found between the software versions, respectively. Conclusion:Although GCC segmentation was improved with software version 6.12 compared with the current version in highly myopic eyes, this did not result in a significant change of the average RNFLT and GCC values, and did not significantly improve the software-provided classification for glaucoma.

Accuracy of macular ganglion-cell complex thickness to total retina thickness ratio to detect glaucoma in white Europeans

Purpose:The aim of this study was to evaluate the diagnostic accuracy of macular ganglion-cell complex (GCC) thickness to total retinal thickness ratio (G/T ratio), a parameter found particularly accurate in Japanese eyes to detect glaucoma and recently proposed for the RTVue-100 Fourier-domain optical coherence tomography (RTVue-100 OCT), and to compare the diagnostic accuracy of this parameter to that of parameters provided by the instrument software in European eyes. Methods:Retinal nerve fiber layer thickness (RNFLT) and macular GCC thickness parameters of 1 randomly selected eye of 177 white European patients (50 healthy, 28 ocular hypertensive, 33 preperimetric glaucoma, and 66 perimetric glaucoma eyes) were measured with an RTVue-100 OCT. Results:The RNFLT and GCC parameter values of the healthy group were significantly higher than those of the various other groups (P<0.001 for all comparisons). For all separation (normal vs. all other eyes; normal vs. preperimetric and perimetric glaucoma eyes; and normal vs. perimetric glaucoma eyes) average RNFLT, inferior RNFLT, average GCC, and inferior GCC showed consistently higher area under receiver operating characteristics curve (AUROC) than G/T ratio. In the normal versus perimetric glaucoma separation, the AUROC values were 0.977, 0.982, 0.969, 0.976, and 0.959 for average RNFLT, inferior RNFLT, average GCC, inferior GCC, and G/T ratio, respectively. Conclusions:In contrast to Japanese eyes, in white Europeans G/T ratio does not improve separation of glaucomatous and healthy eyes.

Influence of a new software version of the RTVue-100 optical coherence tomograph on the detection of glaucomatous structural progression.

Purpose To compare the current (6.3) and a novel software version (6.12) of the RTVue-100 optical coherence tomograph (RTVue-OCT) for detection of glaucomatous inner macular retinal thickness (ganglion cell complex [GCC]) and retinal nerve fiber layer thickness (RNFLT) progression. Methods In this prospective, observational study, 109 participants (17 healthy controls, 20 patients with ocular hypertension, and 72 patients with glaucoma) were investigated with RTVue-OCT at 6-month intervals (mean follow-up 5 years). One eye per participant was evaluated. Results Long-term measurement variability (residual standard deviation) was significantly lower with software version 6.12 than version 6.3 for all parameters in the total population, the normal controls, and the glaucoma group, respectively (p≤0.0065). The between-software-version difference of residual standard deviation did not correlate with the measured thickness for any parameter. In the glaucoma group, the negative GCC slopes (urn/visit) were significantly (p<0.001) steeper, while the negative RNFLT slopes were either similar or less steep with software version 6.12. Significantly more significant negative GCC parameter slopes were found in the glaucoma group and the total population with version 6.12, while no between-software-version difference was seen for the other groups, and for the RNFLT parameters in all groups. Conclusions The new software version reduces long-term RNFLT and GCC measurement variability, provides steeper GCC progression slopes, and provides more cases of significant GCC progression slopes in glaucoma than the current software version. Since version 6.12 is employed in the recently introduced Widefield RTVue-XR instrument, it may improve detection of glaucomatous progression in clinical practice.

Evaluation of octopus polar trend analysis for detection of glaucomatous progression

Purpose To investigate the clinical usefulness of Polar Trend Analysis (PTA) of the Octopus Field Analysis software for detection of glaucoma progression in medically treated glaucoma. Methods One eye each of 52 participants underwent Octopus Normal G2 perimetry and imaging with the RTVue-100 optical coherence tomograph at 6-month intervals (median follow-up 5 years). The eyes were classified as progressors or nonprogressors with PTA, which graphically presents pointwise linear regression analysis of focal defect at the corresponding nerve fiber angle at the disc margin. Polar Trend Analysis progression was defined as more than 1 significantly progressing test point location per sector. Progression of the retinal nerve fiber layer thickness (RNFLT) and ganglion cell complex (GCC) thickness parameters were evaluated with linear regression analysis. Results Seventeen eyes were classified as PTA progressors (all in the inferotemporal or superotemporal areas or in both), and 35 eyes as nonprogressors. Frequencies of statistically significant RNFLT and GCC progressions did not differ significantly between the groups for any peripapillary area (p>0.05 for all comparisons). Significant inferior average RNFLT progression occurred in 50% of the PTA progressor eyes. Long-term measurement variability during the follow-up period was significantly higher in the PTA progressor group for inferior and superior GCC thickness and inferior average RNFLT (p<0.001 for all comparisons). Conclusions In glaucoma, PTA may indicate glaucomatous progression earlier than linear regression analysis of the RNFLT and GCC parameters. It may already draw attention to glaucomatous progression when the alteration of the corresponding structural parameters is represented only by increased long-term variability.

High magnification in vivo evaluation of the mechanism of failure of an Ex-PRESS shunt implanted under the sclera flap

Purpose To investigate the mechanism of fibrosis-related failure of an Ex-PRESS shunt implanted under the scleral flap in trabeculectomy. Methods Case report. Results A patient with end-stage secondary open-angle glaucoma on his only functioning right eye was referred for glaucoma valve implantation. His right eye had undergone congenital cataract surgery in early childhood and posterior chamber lens implantation 20 years ago. During the last 18 months, the right eye underwent pars plana vitrectomy with silicone oil implantation, silicone oil removal, 2 sessions of cyclophotocoagulation, 2 failed trabeculectomies (one of them combined with Ex-PRESS shunt implantation under the scleral flap), and 4 trabeculectomy revisions. At presentation, the intraocular pressure varied between 47 and 52 mm Hg on maximal systemic and topical intraocular pressure–lowering medication. Serial limbus parallel scans made with the CAM-L cornea lens adapter of the Optovue Fourier-domain optical coherence tomograph revealed that the space between the inner surface of the scleral flap and the external orifice of the Ex-PRESS shunt was filled by scar tissue, and the scar tissue appeared to invade the lumen of the shunt. Conclusions The findings suggest that failure of an Ex-PRESS shunt is not always caused by episcleral fibrosis but may also be caused by scar formation between the scleral flap and the implant, inside the surgical sclera tunnel.