Clinical and Experimental Ophthalmology最新文献

Background: Reticular pseudodrusen (RPD) signify a critical phenotype driving vision loss in age-related macular degeneration (AMD). This study sought to develop and externally test a deep learning (DL) model to detect RPD on optical coherence tomography (OCT) scans with expert-level performance.

Methods: RPD were manually segmented in 9800 OCT B-scans from individuals enrolled in a multicentre randomised trial. A DL model for instance segmentation of RPD was developed and evaluated against four retinal specialists in an internal test dataset. The primary outcome was the performance of the DL model for detecting RPD in OCT volumes in five external test datasets compared to two retinal specialists.

Results: In an internal test dataset consisting of 250 OCT B-scans, the DL model produced RPD segmentations that had higher agreement with four retinal specialists (Dice similarity coefficient [DSC] = 0.76) than the agreement amongst the specialists (DSC = 0.68; p < 0.001). In the five external test datasets consisting of 1017 eyes from 812 individuals, the DL model detected RPD in OCT volumes with a similar level of performance as two retinal specialists (area under the receiver operator characteristic curve [AUC] = 0.94, 0.95 and 0.96 respectively; p ≥ 0.32).

Conclusions: We present a DL model for automatic detection of RPD with expert-level performance, which could be used to support the clinical management of AMD. This model has been made publicly available to facilitate future research to understand this critical, yet enigmatic, AMD phenotype.

Background: Endophthalmitis requiring multiple ocular tissue sampling for microbiological testing is uncommon and has not been previously studied. This study aims to analyse cases with at least two ocular tissue samplings and testing of different ocular samples against culture yields.

Methods: A 27-year prospective observational study using data from the Victorian Endophthalmitis Registry, managed through the REDCap data platform. The study included 314 patients (317 eyes) who underwent at least two aqueous or vitreous specimen collections. The primary outcome measures included microbiological culture results from repeat and multiple intraocular samples and identification of isolated microorganisms.

Results: The overall initial culture positivity rate was 75.7%, while the culture positivity rate at the second intervention was 34.7%. First vitreous taps had the highest culture yield (72.6%) among different sample types. Notably, 19.5% of eyes with initial negative vitreous cultures had subsequent positive results. Further analysis showed that 24.4% of eyes with initial negative vitreous cultures had corresponding positive aqueous cultures. Additionally, 12.2% of eyes with negative initial vitreous taps yielded positive cultures from vitreous biopsies or washings from vitrectomy. Staphylococcus and Streptococcus species were the main pathogens isolated (40.4% and 31.3% of cases respectively).

Conclusions: Our study demonstrated the trends and utility of repeated and different ocular tissue sampling in challenging endophthalmitis. Aqueous taps are most useful at the first biopsy, beyond which it has little diagnostic value. A second sampling can be valuable in patients who are initially culture-negative. Surgical specimens contribute meaningfully to the overall culture yield and enhance cumulative culture positivity.

Artificial intelligence (AI) has comparable accuracy to ophthalmologists for diabetic retinopathy (DR) screening, yet its cost-effectiveness is crucial for implementation. Our review of 18 health economic analyses of AI versus manual grading for DR found significant methodological variation, with cost-utility analysis and Markov modelling being the commonest evaluation and modelling approaches, respectively. We identified three key considerations when appraising health economic analyses of AI-enabled DR screening: the importance of contextualised parameters including subgroup analysis, real-world data on adherence to ophthalmology follow-up, and the trade-off between diagnostic accuracy and cost-effectiveness. 39% of studies followed standardised reporting guidelines, and most did not consider improved follow-up after AI screening, potentially underestimating its economic value. Future evaluations should incorporate contextualised parameters, including adherence and regional data, and recognise that the most accurate diagnostic screening may not reflect the most cost-effective. Studies should follow updated reporting guidelines such as CHEERS-AI or PICOTS-ComTeC to improve methodological transparency.

Background: Uveal melanoma (UM) is the most common primary intraocular tumour. Despite effective local therapies, UM has a high risk of metastatic recurrence, most frequently to the liver. A significant proportion of patients treated definitively for primary UM eventually experience metastatic disease. Systemic surveillance to detect recurrence is critical to maximise therapeutic options. Whilst international guidelines exist, there are currently no standardised Australian guidelines for surveillance imaging. This systematic review examines the literature regarding systemic surveillance methods following local treatment for UM.

Methods: Medline, Embase and PubMed databases were searched, from 2010 to 01-07-2024, using keywords related to uveal melanoma and surveillance. Eligible studies were identified by two independent reviewers, and a systematic review was undertaken.

Results: Of 840 records, six guidelines and institutional consensus statements were identified, and an additional 13 studies were included. Most studies were cohort studies (n = 7), with the rest being case-control studies and reliability analyses. Risk stratification methods and surveillance strategies varied, with most studies recommending increased frequency (at least every 6 months) and higher-resolution imaging modalities (MRI over ultrasound) for higher-risk patients.

Conclusion: Despite several published guidelines, existing evidence regarding optimal surveillance strategies in localised primary UM is of variable quality, relying on cohort studies and limited by heterogeneity, as assessed by the modified Newcastle-Ottawa Scale. There is a clear need to further define local practices and outcomes to direct future guidelines.

Background: The Feline Leukaemia Virus Subgroup C Receptor 1 (FLVCR1) has been recognized as a heme exporter essential for erythropoiesis, and emerging research identifies its novel function as a choline transporter. Mutations in FLVCR1 have been associated with the pathogenesis of retinitis pigmentosa (RP); however, the roles of FLVCR1 in retina remain unexplored. This study aims to elucidate the connection between FLVCR1 and RP and investigate potential therapeutic interventions.

Methods: Utilizing CRISPR/Cas9 technology, we established retina-specific Flvcr1 knockout (SKO) and rod-specific Flvcr1 knockout (RKO) mouse models to investigate the in vivo functions of FLVCR1 in the retina. We performed optical coherence tomography (OCT) to assess the retinal thickness, electroretinography (ERG) to test the retinal function and histopathological sections and staining to analyse the pathological changes. Additionally, we administered choline supplementation treatment (CST) to evaluate its potential efficacy in alleviating symptoms of retinal degeneration.

Results: Genotyping and immunoblotting analyses confirmed the successful establishment of the SKO and RKO mouse models. Retinal degeneration in SKO mice manifested at postnatal day 14, while its onset in RKO mice occurred at P25, including diminished scotopic electroretinogram (ERG) responses, progressive degeneration of photoreceptor cells, infiltration of microglia into the outer nuclear layer (ONL) and disruption of mitochondrial homeostasis. Notably, we found that choline supplementation in RKO mice alleviated the associated phenotypes.

Conclusions: We developed two innovative mouse models and revealed that FLVCR1 is critical for maintaining mitochondrial homeostasis and supporting photoreceptor survival. Choline supplementation serves as a therapeutic intervention for RP caused by FLVCR1 mutations.