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.

Detection of macular atrophy in age-related macular degeneration aided by artificial intelligence.

INTRODUCTION: Age-related macular degeneration (AMD) is a leading cause of irreversible visual impairment worldwide. The endpoint of AMD, both in its dry or wet form, is macular atrophy (MA) which is characterized by the permanent loss of the RPE and overlying photoreceptors either in dry AMD or in wet AMD. A recognized unmet need in AMD is the early detection of MA development. AREAS COVERED: Artificial Intelligence (AI) has demonstrated great impact in detection of retinal diseases, especially with its robust ability to analyze big data afforded by ophthalmic imaging modalities, such as color fundus photography (CFP), fundus autofluorescence (FAF), near-infrared reflectance (NIR), and optical coherence tomography (OCT). Among these, OCT has been shown to have great promise in identifying early MA using the new criteria in 2018. EXPERT OPINION: There are few studies in which AI-OCT methods have been used to identify MA; however, results are very promising when compared to other imaging modalities. In this paper, we review the development and advances of ophthalmic imaging modalities and their combination with AI technology to detect MA in AMD. In addition, we emphasize the application of AI-OCT as an objective, cost-effective tool for the early detection and monitoring of the progression of MA in AMD.

Initial experiences of cataract & lens surgery in 1269 patients in outpatient clean rooms using a portable laminar air flow device.

BACKGROUND: In 2020, routine cataract surgery was halted in most countries due to the COVID-19 pandemic in order to reduce transmission. With a consequent lack of theatre space, we developed a safe cataract pathway in outpatient department clean rooms to minimize patient exposure and time spent in hospital using a sterile laminar air flow device. We describe our initial experiences of restarting elective cataract surgery in the UK outpatient setting, outside of the operating theatre environment. METHODS: This was a prospective consecutive study of our clinical practice. A sterile air zone unit, the Toul Meditech Operio Mobile device, was used to create a sterile surgical site in three separate outpatient clean rooms from May 2020 to December 2021 in different geographical locations within Herefordshire, UK. Observations of the time spent in the department and a formal patient satisfaction survey were carried out for the initial 100 patients. All patients were followed up to assess development of post-operative complications. RESULTS: 1269 patients were included in the study. No patients sustained post-operative infection (n = 0/1269, 0%). For the initial 100 patients, the average time spent within the department was 74.3 min (unilateral cases, range 45-115 min) and 93.1 min (bilateral, 55-135 min). Patient satisfaction was high. CONCLUSION: Initial results demonstrate a safe, efficient and effective cataract surgery pathway with high patient satisfaction by converting outpatient clean rooms into ophthalmic operating theatres using the Toul Meditech Operio Mobile.

Naturally occurring neuroprotectants in glaucoma.

With the increasing global burden of glaucoma-caused blindness there is a significant need to develop therapies that both enable early detection of retinal neurodegeneration, and help protect cells from the neurodegenerative processes of glaucoma. In this chapter, we discuss potential neuroprotective agents that are present naturally and examine their role and suitability as therapies in glaucoma. These agents have been found to have anti-apoptotic and anti-inflammatory mechanisms of action which may aid the resilience of retinal ganglion cells and enable them to withstand potential insults that trigger cell death. We highlight how these properties could be translated into clinical practice and the barriers needing to be overcome in order to achieve this.

Single axonal morphology and termination to cerebellar aldolase C stripes characterize distinct spinocerebellar projection systems originating from the thoracic spinal cord in the mouse.

The spinocerebellar projection has an essential role in sensorimotor coordination of limbs and the trunk. Multiple groups of spinocerebellar projections have been identified in retrograde labeling studies. In this study, we aimed at characterizing projection patterns of these groups using a combination of anterograde labeling of the thoracic spinal cord and aldolase C immunostaining of longitudinal stripes of the cerebellar cortex in the mouse. We reconstructed 22 single spinocerebellar axons, wholly in the cerebellum and brain stem and partly, in the spinal cord. They were classified into three groups, (a) non-crossed axons of Clarke's column neurons (NCC, 8 axons), (b) non-crossed axons of marginal Clarke's column neurons (NMCC, 7 axons), and (c) crossed axons of neurons in the medial ventral horn (CMVH, 7 axons), based on previous retrograde labeling studies. While NCC axons projected mainly to multiple bilateral stripes in vermal lobules II-IV and VIII-IX, and the ipsilateral medial cerebellar nucleus, NMCC axons projected mainly to ipsilateral stripes in paravermal lobules II-V and copula pyramidis, and the anterior interposed nucleus. CMVH axons projected bilaterally to multiple stripes in lobules II-V with a small number of terminals but had abundant collaterals in the spinal cord and medullary reticular nuclei as well as in the vestibular and cerebellar nuclei. The results indicate that, while CMVH axons overlap with propriospinal and spinoreticular projections, NCC and NMCC axons are primarily spinocerebellar axons, which seem to be involved in relatively more proximal and distal sensorimotor controls, respectively.