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

A SPATIALLY VARYING HIERARCHICAL RANDOM EFFECTS MODEL FOR LONGITUDINAL MACULAR STRUCTURAL DATA IN GLAUCOMA PATIENTS

We model longitudinal macular thickness measurements to monitor the course of glaucoma and prevent vision loss due to disease progression. The macular thickness varies over a 6 × 6 grid of locations on the retina, with additional variability arising from the imaging process at each visit. currently, ophthalmologists estimate slopes using repeated simple linear regression for each subject and location. To estimate slopes more precisely, we develop a novel Bayesian hierarchical model for multiple subjects with spatially varying population-level and subject-level coefficients, borrowing information over subjects and measurement locations. We augment the model with visit effects to account for observed spatially correlated visit-specific errors. We model spatially varying: (a) intercepts, (b) slopes, and (c) log-residual standard deviations (SD) with multivariate Gaussian process priors with Matérn cross-covariance functions. Each marginal process assumes an exponential kernel with its own SD and spatial correlation matrix. We develop our models for and apply them to data from the Advanced Glaucoma Progression Study. We show that including visit effects in the model reduces error in predicting future thickness measurements and greatly improves model fit.

Glaucoma progression. Clinical practice guide

OBJECTIVE

To provide general recommendations that serve as a guide for the evaluation and management of glaucomatous progression in daily clinical practice based on the existing quality of clinical evidence.

METHODS

After defining the objectives and scope of the guide, the working group was formed and structured clinical questions were formulated following the PICO (Patient, Intervention, Comparison, Outcomes) format. Once all the existing clinical evidence had been independently evaluated with the AMSTAR 2 (Assessment of Multiple Systematic Reviews) and Cochrane "Risk of bias" tools by at least two reviewers, recommendations were formulated following the Scottish Intercollegiate Guideline network (SIGN) methodology.

RESULTS

Recommendations with their corresponding levels of evidence that may be useful in the interpretation and decision-making related to the different methods for the detection of glaucomatous progression are presented.

CONCLUSIONS

Despite the fact that for many of the questions the level of scientific evidence available is not very high, this clinical practice guideline offers an updated review of the different existing aspects related to the evaluation and management of glaucomatous progression.

Macular imaging with optical coherence tomography in glaucoma

With the advent of spectral-domain optical coherence tomography, imaging of the posterior segment of the eye can be carried out rapidly at multiple anatomical locations, including the optic nerve head, circumpapillary retinal nerve fiber layer, and macula. There is now ample evidence to support the role of spectral-domain optical coherence tomography imaging of the macula for detection of early glaucoma. Macular spectral-domain optical coherence tomography measurements demonstrate high reproducibility, and evidence on its utility for detection of glaucoma progression is accumulating. We present a comprehensive review of macular spectral-domain optical coherence tomography imaging emerging as an essential diagnostic tool in glaucoma.

RTVue XR AngioVue Optical Coherence Tomography Angiography Software Upgrade Impacts on Retinal Thickness and Vessel Density Measurements

Purpose

To determine the impact of an AngioVue software upgrade on total retinal thickness (RT) and inner retinal vessel density (VD) measurements derived from optical coherence tomography angiography (OCTA).

Methods

Optovue OCTA images (3 × 3 mm) from 126 individuals (105 healthy eyes and 72 eyes with retinal disease) were acquired before an upgrade of the AngioVue software, which resulted in an inward shift of the outer boundary of the inner retinal vessels and improved Bruch's membrane segmentation. Total RT and inner retinal VD values were extracted before and after the software upgrade for comparison. Bias and limits of agreement (LA) were calculated.

Results

The mean (SD) age of participants was 46 (17) years. Mean (LA) foveal RT increased by 3.0 (–11 to +17) and 3.7 (–11 to +18) µm (P < 0.001) and parafoveal RT increased by 9.7 (–3.8 to +23) and 6.4 (–2.5 to +15) µm (P < 0.001) in healthy and diseased retina, respectively. Mean (LA) foveal inner retinal VD decreased by 6.6 (2.5–11) and 7.7 (0.4–15) percentage units (P < 0.001) and parafoveal inner retinal VD decreased by 4.1 (1.2–7.0) and 4.7 (0.5–8.9) percentage units (P < 0.001) in healthy and diseased retina, respectively.

Conclusions

The AngioVue software upgrade resulted in an unexpected increase in total RT and an expected reduction in inner retinal VD measurements in all regions due to altered segmentation.

Translational Relevance

RT and VD measures derived from the newer AngioVue software version are not directly comparable to the reported normative data derived from the older software.

Morphological and Functional Evaluation of Oral Citicoline Therapy in Chronic Open-Angle Glaucoma Patients: A Pilot Study With a 2-Year Follow-Up

Aims: To study the neuroprotective effect of oral citicoline (CT) therapy in primary open-angle glaucoma (POAG).

Methods: This study included one eye each of 60 POAG patients. Patients were randomly divided into two groups (A and B) of 30 participants each. Only patients of group A were administered with CT therapy. Age, sex, and disease duration were matched between groups. Despite a stable intraocular pressure (IOP), a slow disease progression—assessed by standard automated white-on-white perimetry (SAP) in the previous 3 years—occurred in all patients. All patients underwent a complete eye examination, including IOP measurement, SAP, retinal nerve fiber layer (RNFL) thickness, and ganglion cell complex (GCC) thickness measurements with optical coherence tomography (OCT), before starting CT treatment and at 6, 12, 18, and 24 months’ follow-up. Parameter differences between groups were evaluated at each eye check.

Results: After 18 months, mean values of SAP mean deviation (MD) of group A were significantly (p = 0.039) higher (−7.25 db) than those of group B (−8.64 db). Moreover, they appeared stable in the following visits, whereas in group B, mean MD values continued to significantly (p < 0.001) decrease (−9.28 db) over time. Mean RNFL and GCC thickness in group A were significantly (p < 0.01) higher (70.39 and 71.19 μm, respectively) than in group B (64.91 and 65.60 μm, respectively) after 12 months of CT therapy. Furthermore, they appeared to be stable over the later visits, whereas they thinned significantly (p < 0.001) over time in group B.

Conclusion: These findings suggest that CT therapy seems to be effective in slowing POAG progression. Further studies on a larger population and with a longer follow-up are needed to confirm this pilot investigation.

Evaluation of Retinal Nerve Fiber Layer Thickness and Ganglion Cell Complex Progression Rates in Healthy, Ocular Hypertensive, and Glaucoma Eyes With the Avanti RTVue-XR Optical Coherence Tomograph Based on 5-Year Follow-up

PURPOSE

To determine retinal nerve fiber layer thickness (RNFLT) and ganglion cell complex (GCC) progression rates for healthy eyes and undertreatment ocular hypertensive (OHT) and glaucoma eyes with the Avanti RTVue-XR optical coherence tomography.

MATERIALS AND METHODS

Seventeen healthy subjects (34 eyes), 17 medically treated OHT patients (34 eyes), and 67 medically treated glaucoma patients (122 eyes) were imaged prospectively at 6-month intervals (median follow-up 5.3 y, 11 visits).

RESULTS

A minimal negative correlation between baseline RNFLT and RNFLT progression was found in the glaucoma group (r=-0.1708, P=0.0493). In the other groups no correlation between baseline RNFLT or GCC and RNFLT or GCC progression was found, respectively. The mean±SD of the rate of change was -0.33±0.51, -0.44±0.62, and -0.69±0.93 μm/y for average RNFLT, and -0.53±0.36, -0.54±0.52, and -0.80±0.78 for average GCC, for the normal, OHT, and glaucoma eyes, respectively (P>0.05 for all between-group comparisons). In the normal group the highest progression rate was -1.52 μm/y for average RNFLT and -1.28 μm/y for average GCC. Despite maximal medical treatment, progression in the glaucoma group exceeded the highest progression rate of the normal group in 18 eyes (14.8%) for average RNFLT and 24 eyes (19.7%) for average GCC.

CONCLUSIONS

We determined progression rates for untreated healthy and under treatment OHT and glaucoma eyes with the Avanti RTVue-XR optical coherence tomography. We found that an average RNFLT progression rate faster than -1.5 μm/y, and an average GCC progression rate faster than -1.3 μm/y are strongly suggestive for uncontrolled glaucomatous progression. Detection of uncontrolled structural progression with trend analysis may assist the early detection of fast progressors.

Clinical Utility of Optical Coherence Tomography in Glaucoma

Optical coherence tomography (OCT) has established itself as the dominant imaging modality in the management of glaucoma and retinal diseases, providing high-resolution visualization of ocular microstructures and objective quantification of tissue thickness and change. This article reviews the history of OCT imaging with a specific focus on glaucoma. We examine the clinical utility of OCT with respect to diagnosis and progression monitoring, with additional emphasis on advances in OCT technology that continue to facilitate glaucoma research and inform clinical management strategies.