Quality assessment of anterior segment OCT images: Development and validation of quality criteria.

BACKGROUND: The utility of medical imaging is dependant on image quality. We aimed to develop and validate quality criteria for ocular anterior segment optical coherence tomography (AS-OCT) images. METHODS: We undertook a cross-sectional study using AS-OCT images from patients aged 6-16. A novel three-level grading system (good, limited or poor) was developed based on the presence of image artefact (categorised as lid, eyelash, cropping, glare, or movement artefact). Three independent experts graded 2825 images, with agreement assessed using confusion matrices and intraclass correlation coefficients (ICC) for each parameter. RESULTS: There was very good inter-grader IQA agreement assessing image quality with ICC 0.85 (95 %CI: 0.84-0.87). The most commonly occurring artefact was eyelash artefact (1008/2825 images, 36 %). Graders labelled 621/2825 (22 %) images as good and 384 (14 %) as poor. There was complete agreement at either end of the confusion matrix with no 'good' images labelled as 'poor' by other graders, and vice versa. Similarly, there was very good agreement when assessing presence of lash (0.96,0.94-0.98), movement (0.97,0.96-0.99), glare (0.82,0.80-0.84) and cropping (0.90,0.88-0.92). CONCLUSIONS: The novel image quality assessment criteria (IQAC) described here have good interobserver agreement overall, and excellent agreement on the differentiation between 'good' and 'poor' quality images. The large proportion of images graded as 'limited' suggests the need for refine this classification, using the specific IQAC features, for which we also report high interobserver agreement. These findings support the future potential for wider clinical and community care implementation of AS-OCT for the diagnosis and monitoring of ocular disease.

Quantitative and qualitative assessment of anterior segment optical coherence tomography capture of disease state in childhood anterior uveitis.

BACKGROUND/AIMS: Anterior segment optical coherence tomography (AS-OCT) assessment of anterior chamber inflammation is an emerging tool. We describe the performance of AS-OCT in a paediatric population. METHODS: A mixed-methods prospective study, using routine clinical assessment as reference standard, and AS-OCT, with Tomey CASIA2 or Heidelberg Spectralis HS1, as index test, with data collected on patient perceptions of imaging. Repeatability, diagnostic indices, responsiveness to clinical change and clinical correlations of imaging-based metrics (image cell count, size, density and brightness) were assessed, with construction of receiver operated characteristic curves. Exploratory thematic analysis of responses from families was undertaken. RESULTS: A total of 90 children (180 eyes) underwent imaging. Bland Altman limits of agreement for CASIA2 repeatability ranged from +17 cells (95% CI 13.6 to 21.1) to -19 cells (95% CI -15.6 to -23.2) and HS1 from +1 (95% CI 0.9 to 1.2) to -1.0 (-1.2 to -0.8) cells. CASIA2 imaging had higher sensitivity of 0.92 (95% CI 0.78 to 0.97) vs HS1 imaging 0.17 (95% CI 0.07 to 0.34), with positive correlation between clinical grade and CASIA2 cell count (coefficient 12.8, p=0.02, 95% CI 2.2 to 23.4). Change in clinical grade at follow-up examinations correlated with change in image based 'cell' count (r2=0.79, p<0.001). Patients reported a potential positive impact of seeing their disease activity. CONCLUSION: Our findings suggest that OCT-based imaging holds the promise of deeper understanding of disease, improved patient experience and more granular monitoring of activity with resultant improved outcomes, but further work is needed to refine acquisition and analysis protocols.

Imaging-Based Uveitis Surveillance in Juvenile Idiopathic Arthritis: Feasibility, Acceptability, and Diagnostic Performance.

OBJECTIVE: Children with juvenile idiopathic arthritis (JIA) need regular examinations for uveitis to avoid visual morbidity from the most common extraarticular manifestation of disease. This study was undertaken to investigate the feasibility, acceptability, and performance of optical coherence tomography (OCT) imaging-based diagnosis of uveitis. METHODS: This observational cross-sectional study included children with and those without uveitis. The children underwent routine clinical examinations and anterior segment OCT scanning of intraocular inflammatory cells. Acceptability of image acquisition was assessed using a visual analog scale and length of time needed to acquire images. Interobserver and intraobserver variability of manual counting of acquired images (Bland-Altman limits of agreement), correlation between imaging and routine assessment, and sensitivity and specificity of anterior segment OCT detection of active inflammation were assessed. RESULTS: Of the 26 children ages 3-15 years (median age 8 years) who underwent imaging, 12 had active inflammation. All patients rated the acceptability of image acquisition as at least 8.5 on a scale of 0-10. Time taken to acquire images ranged from 1.5 minutes to 22 minutes (median time 8 minutes). There was good positive correlation between clinical assessment and image-based cell quantification (R2 = 0.63, P = 0.002). Sensitivity of anterior segment OCT manual image cell count for diagnosis of active inflammation was 92% (95% confidence interval [95% CI] 62-99%), specificity was 86% (95% CI 58-98%), and negative predictive value (ruling out uveitis) was 92% (95% CI 65-99%). CONCLUSION: Non-contact, high-resolution imaging for JIA uveitis surveillance is feasible, acceptable to patients, and holds the promise of transforming pediatric practice. Further work is needed to determine the analytic and clinical validity of anterior segment OCT quantification of active inflammation, and the clinical utility and cost-effectiveness of imaging-based disease monitoring.