To evaluate retinal nerve fiber layer (RNFL), optic nerve head (ONH), and macular thickness measurements for glaucoma detection using the RTVue spectral domain optical coherence tomograph.
...Diagnostic, case-control study.
One hundred forty eyes of 106 glaucoma patients and 74 eyes of 40 healthy subjects from the Diagnostic Innovations in Glaucoma Study (DIGS).
All patients underwent ocular imaging with the commercially available RTVue. Optic nerve head, RNFL thickness, and macular thickness scans were obtained during the same visit. Receiver operating characteristic (ROC) curves and sensitivities at fixed specificities (80% and 95%) were calculated for each parameter.
Areas under the ROC curves (AUC) and sensitivities at fixed specificities of 80% and 95%.
The AUC for the RNFL parameter with best performance, inferior quadrant thickness, was significantly higher than that of the best-performing ONH parameter, inferior rim area (0.884 vs 0.812, respectively; P = 0.04). There was no difference between ROC curve areas of the best RNFL thickness parameters and the best inner macular thickness measurement, ganglion cell complex root mean square (ROC curve area = 0.870).
The RTVue RNFL and inner retinal macular thickness measurements had good ability to detect eyes with glaucomatous visual field loss and performed significantly better than ONH parameters.
To compare the rates of retinal nerve fiber layer (RNFL) loss in patients suspected of having glaucoma who developed visual field damage (VFD) with those who did not develop VFD and to determine ...whether the rate of RNFL loss can be used to predict the development of VFD.
Prospective, observational cohort study.
Glaucoma suspects, defined as having glaucomatous optic neuropathy or ocular hypertension (intraocular pressure, >21 mmHg) without repeatable VFD at baseline, from the Diagnostic Innovations in Glaucoma Study and the African Descent and Glaucoma Evaluation Study.
Global and quadrant RNFL thickness (RNFLT) were measured with the Spectralis spectral-domain optical coherence tomography (SD-OCT; Spectralis HRA+OCT Heidelberg Engineering, Heidelberg, Germany). Visual field damage was defined as having 3 consecutive abnormal visual fields. The rate of RNFL loss in eyes developing VFD was compared to eyes not developing VFD using multivariate linear mixed-effects models. A joint longitudinal survival model used the estimated RNFLT slope to predict the risk of developing VFD, while adjusting for potential confounding variables.
The rate of RNFL thinning and the probability of developing VFD.
Four hundred fifty-four eyes of 294 glaucoma suspects were included. The average number of SD-OCT examinations was 4.6 (range, 2-9), with median follow-up of 2.2 years (0.4-4.1 years). Forty eyes (8.8%) developed VFD. The estimated mean rate of global RNFL loss was significantly faster in eyes that developed VFD compared with eyes that did not develop VFD (-2.02 μm/year vs. -0.82 μm/year; P<0.001). The joint longitudinal survival model showed that each 1-μm/year faster rate of global RNFL loss corresponded to a 2.05-times higher risk of developing VFD (hazard ratio, 2.05; 95% confidence interval, 1.14-3.71; P = 0.017).
The rate of global RNFL loss was more than twice as fast in eyes that developed VFD compared with eyes that did not develop VFD. A joint longitudinal survival model showed that a 1-μm/year faster rate of RNFLT loss corresponded to a 2.05-times higher risk of developing VFD. These results suggest that measuring the rate of SD-OCT RNFL loss may be a useful tool to help identify patients who are at a high risk of developing visual field loss.
Abstract Early diagnosis of glaucoma is critical to prevent permanent structural damage and irreversible vision loss. Detection of glaucoma typically relies on examination of structural damage to the ...optic nerve combined with measurements of visual function. To aid the clinician in evaluation of visual function and structure, computer-based devices such as confocal scanning laser ophthalmoscopy, scanning laser polarimetry, and optical coherence tomography provide quantitative assessments of structural damage, and visual function testing includes standard automated perimetry as well as selective techniques, including short-wavelength automated perimetry and frequency-doubling technology perimetry are available. This article will review current literature on diagnostic modalities available for glaucoma with emphasis on the best evidence available in the literature to support their use in clinical practice.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
To investigate whether long-term intraocular pressure (IOP) fluctuations are a risk factor for conversion from ocular hypertension to glaucoma.
Observational cohort study.
The study included 252 eyes ...of 126 patients with ocular hypertension observed untreated as part of the Diagnostic Innovations in Glaucoma Study. At baseline, ocular hypertensive eyes had elevated IOP, normal visual fields (VFs) on standard automated perimetry, and normal optic discs as evaluated by stereophotograph assessment.
Glaucoma conversion was defined as development of reproducible VF loss or optic disc damage. Analyses included all IOP measurements from the baseline visit to time of progression (for converters) and last follow-up (for nonconverters). Mean IOP and IOP fluctuation were calculated as the arithmetic mean and standard deviation (SD), respectively, of all available IOP measurements per eye.
Univariable and multivariable Cox regression analyses were used to evaluate the association between IOP fluctuation and time to progression. Multivariable models adjusted for age, mean IOP, central corneal thickness, vertical cup-to-disc ratio, and pattern SD.
Forty eyes of 31 subjects developed glaucoma during follow-up. Mean IOPs during follow-up were 25.4+/-4.2 mmHg for the eyes that converted to glaucoma and 24.1+/-3.5 mmHg for the eyes that did not. Corresponding values for IOP fluctuation were 3.16+/-1.35 mmHg and 2.77+/-1.11 mmHg, respectively. Intraocular pressure fluctuation was not a risk factor for conversion to glaucoma both in univariable analysis (hazard ratio HR, 1.30 per 1 mmHg higher; 95% confidence interval CI, 0.76-1.96; P = 0.092) and in multivariable analysis (adjusted HR, 1.08 per 1 mmHg higher; 95% CI, 0.79-1.48; P = 0.620). Mean IOP during follow-up was a significant risk factor for progression both in univariable analysis (HR = 1.16 per 1 mmHg higher; 95% CI, 1.04-1.31; P = 0.010) and in multivariable analysis (adjusted HR, 1.20 per 1 mmHg higher; 95% CI, 1.06-1.36; P = 0.005).
Long-term IOP fluctuations do not appear to be significantly associated with the risk of developing glaucoma in untreated ocular hypertensive subjects.
Purpose To assess the agreement of parapapillary retinal nerve fiber layer (RNFL) thickness measurements among 3 spectral-domain optical coherence tomography (SD-OCT) instruments. Design ...Observational, cross-sectional study. Methods Three hundred thirty eyes (88 with glaucoma, 206 glaucoma suspects, 36 healthy) from 208 individuals enrolled in the Diagnostic Innovations in Glaucoma Study (DIGS) were imaged using RTVue, Spectralis and Cirrus in a single visit. Agreement among RNFL thickness measurements was assessed using Bland-Altman plots. The influence of age, axial length, disc size, race, spherical equivalent, and disease severity on the pairwise agreements between different instruments was assessed by regression analysis. Results Although RNFL thickness measurements between different instruments were highly correlated, Bland-Altman analyses indicated the presence of fixed and proportional biases for most of the pairwise agreements. In general, RTVue measurements tended to be thicker than Spectralis and Cirrus measurements. The agreement in average RNFL thickness measurements between RTVue and Spectralis was affected by age ( P = .001) and spherical equivalent ( P < .001), whereas the agreement between Spectralis and Cirrus was affected by axial length ( P = .004) and spherical equivalent ( P < .001). Disease severity influenced the agreement between Spectralis and both RTVue and Cirrus ( P = .001). Disc area and race did not influence the agreement among the devices. Conclusions RNFL thickness measurements obtained by different SD-OCT instruments were not entirely compatible and therefore they should not be used interchangeably. This may be attributable in part to differences in RNFL detection algorithms. Comparisons with histologic measurements could determine which technique is most accurate.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
To evaluate the relationship between intraocular pressure (IOP) and progressive retinal nerve fiber layer (RNFL) loss, as measured by scanning laser polarimetry with enhanced corneal compensation ...(GDx ECC), in a cohort of glaucoma patients and individuals suspected of having the disease followed over time.
Observational cohort study.
The study included 344 eyes of 204 patients recruited from the Diagnostic Innovations in Glaucoma Study (DIGS). There were 98 eyes (28%) with a diagnosis of glaucoma and 246 (72%) were considered glaucoma suspects at baseline.
Images were obtained annually with the GDx ECC scanning laser polarimeter, along with stereophotographs and SAP. The study included a total of 1211 GDx ECC visits with an average of 3.5 visits per eye. Progression was determined by the Guided Progression Analysis software for SAP and by masked assessment of stereophotographs performed by expert graders.
Random coefficient models were used to evaluate the relationship between IOP and RNFL thickness measurements over time in progressors and nonprogressors. Models were adjusted for baseline diagnosis and central corneal thickness.
For all 344 eyes, the overall rate of change for the GDx ECC average thickness at an average IOP of 17 mmHg was -0.25 microm per year (P = 0.002). Each 1-mmHg higher IOP was associated with an additional loss of 0.05 microm per year of RNFL (P = 0.001). Twenty-nine eyes (8%) showed progression on SAP and/or optic disc stereophotographs. These eyes had a significantly higher rate of RNFL change (-0.95 microm/year) than nonprogressors (-0.17 microm/year; P = 0.001). For progressors, each 1-mmHg higher IOP was associated with an additional loss of 0.13 microm per year of RNFL.
Higher levels of IOP during follow-up were significantly related to higher rates of progressive RNFL loss detected by the GDx ECC. These findings suggest that the GDx ECC may be helpful in monitoring progression and estimating rates of change in patients with glaucoma or suspected of having the disease. Also, they may contribute to a better understanding of the relationship between IOP and structural deterioration in glaucoma.
Proprietary or commercial disclosure may be found after the references.
To assess the spatial distribution of glaucomatous visual field defects (VFDs) obtained with regionally condensed stimulus arrangements.
Sixty-three eyes of 63 glaucoma subjects were examined with ...threshold-estimating automated static perimetry (full threshold 4-2-1 dB strategy with at least three reversals) on an automatic campimeter or a full-field perimeter. Stimuli were added by the examiner to regionally enhance spatial resolution in regions that were suspicious for a glaucomatous VFD. These regions were characterized by contiguous local VFDs, attributable to the retinal nerve fiber bundle course according to the impression of the examiner. The added stimulus locations were subsets of a predefined, dense perimetric grid. All VFD locations with P < 0.05 (total deviation plots) were assessed by superimposing the visual field records of all participants.
Glaucomatous VFD loss occurred more frequently in the upper than in the lower hemifield, with a typical retinal nerve fiber-related pattern and a preference of the nasal step region. More than 50% of the eyes with predominantly mild to moderate glaucomatous field loss showed defective locations in the immediate superior paracentral region within an eccentricity of 3°.
Conventional thresholding white-on-white perimetry with regionally enhanced spatial resolution reveals that glaucomatous visual field loss affects the immediate paracentral area, especially the upper hemifield, in many eyes with only mild to moderate glaucomatous visual field loss. Detailed knowledge about the spatial pattern and the local frequency distribution of glaucomatous VFDs is an essential prerequisite for creating regionally condensed stimulus arrangements for adequate detection and follow-up of functional glaucomatous damage.
Purpose To evaluate racial differences in the development of visual field (VF) damage in glaucoma suspects. Design Prospective, observational cohort study. Methods Six hundred thirty-six eyes from ...357 glaucoma suspects with normal VF at baseline were included from the multicenter African Descent and Glaucoma Evaluation Study (ADAGES). Racial differences in the development of VF damage were examined using multivariable Cox proportional hazard models. Results Thirty one of 122 African-descent participants (25.4%) and 47 of 235 European-descent participants (20.0%) developed VF damage ( P = .078). In multivariable analysis, worse baseline VF mean deviation, higher mean arterial pressure during follow-up, and a race ∗ mean intraocular pressure (IOP) interaction term were significantly associated with the development of VF damage, suggesting that racial differences in the risk of VF damage varied by IOP. At higher mean IOP levels, race was predictive of the development of VF damage even after adjusting for potentially confounding factors. At mean IOPs during follow-up of 22, 24, and 26 mm Hg, multivariable hazard ratios (95% confidence intervals) for the development of VF damage in African-descent compared to European-descent subjects were 2.03 (1.15–3.57), 2.71 (1.39–5.29), and 3.61 (1.61–8.08), respectively. However, at lower mean IOP levels (below 22 mm Hg) during follow-up, African descent was not predictive of the development of VF damage. Conclusion In this cohort of glaucoma suspects with similar access to treatment, multivariate analysis revealed that at higher mean IOP during follow-up, individuals of African descent were more likely to develop VF damage than individuals of European descent.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
To assess the strength of the association between retinal nerve fiber layer (RNFL) thickness and optic disc topography measured with confocal retinal tomography (HRT II; Heidelberg Engineering, ...Dossenheim, Germany), optical coherence tomography (StratusOCT; Carl Zeiss Meditec, Inc., Dublin, CA), and scanning laser polarimetry (GDx with variable corneal compensator, VCC; Carl Zeiss Meditec, Inc.), and visual field (VF) sensitivity and to determine whether this association is better expressed as a linear or nonlinear function.
One hundred twenty-seven patients with glaucoma or suspected glaucoma and 127 healthy eyes from enrollees in the Diagnostic Innovations in Glaucoma Study (DIGS) were tested on HRT II, StratusOCT, GDx VCC, and standard automated perimetry (SAP, with the Swedish Interactive Thresholding Algorithm SITA) within 3 months of each other. Linear and logarithmic associations between RNFL thickness (HRT II, StratusOCT, and GDx VCC) and neuroretinal rim area (HRT II) and SAP sensitivity expressed in decibels were determined globally and for six RNFL/optic disc regions (inferonasal, inferotemporal, temporal, superotemporal, superonasal, and nasal) and six corresponding VF regions (superior, superonasal, nasal, inferonasal, inferior, and temporal).
The associations (R2) between global and regional RNFL/optic disc measurements and VF sensitivity ranged from <0.01 (temporal RNFL, nasal VF, and nasal RNFL, temporal VF; linear and logarithmic associations) to 0.26 (inferotemporal RNFL, superonasal VF; logarithmic association) for HRT II; from 0.02 (temporal RNFL, nasal VF; linear association) to 0.38 (inferotemporal RNFL, superonasal VF; logarithmic association) for OCT; and from 0.03 (temporal RNFL, nasal VF; linear association) to 0.21 (inferotemporal RNFL, superonasal VF; logarithmic association) for GDx. Structure-function relationships generally were strongest between the inferotemporal RNFL-optic disc sector and the superonasal visual field and were significantly stronger for StratusOCT RNFL thickness than for other instruments in this region. Global associations (linear and logarithmic) were significantly stronger using OCT compared with HRT. In most cases, logarithmic fits were not significantly better than linear fits when visual sensitivity was expressed in log units (i.e., decibels).
These results suggest that structure-function associations are strongest with StratusOCT measurements and are similar between HRT II and GDx VCC and these associations are generally no better expressed logarithmically than linearly when healthy, suspect, and glaucomatous eyes are considered.
To evaluate the effect of disease severity on the diagnostic accuracy of the Cirrus Optical Coherence Tomograph (Cirrus HD-OCT; Carl Zeiss Meditec, Inc., Dublin, CA) for glaucoma detection.
One ...hundred thirty-five glaucomatous eyes of 99 patients and 79 normal eyes of 47 control subjects were recruited from the longitudinal Diagnostic Innovations in Glaucoma Study (DIGS). The severity of the disease was graded based on the visual field index (VFI) from standard automated perimetry. Imaging of the retinal nerve fiber layer (RNFL) was obtained using the optic disc cube protocol available on the Cirrus HD-OCT. Pooled receiver operating characteristic (ROC) curves were initially obtained for each parameter of the Cirrus HD-OCT. The effect of disease severity on diagnostic performance was evaluated by fitting an ROC regression model, with VFI used as a covariate, and calculating the area under the ROC curve (AUCs) for different levels of disease severity.
The largest pooled AUCs were for average thickness (0.892), inferior quadrant thickness (0.881), and superior quadrant thickness (0.874). Disease severity had a significant influence on the detection of glaucoma. For the average RNFL thickness parameter, AUCs were 0.962, 0.932, 0.886, and 0.822 for VFIs of 70%, 80%, 90%, and 100%, respectively.
Disease severity had a significant effect on the diagnostic performance of the Cirrus HD-OCT and thus should be considered when interpreting results from this device and when considering the potential applications of this instrument for diagnosing glaucoma in the various clinical settings.
PDF
