Epiretinal membrane in uveitis: Rate, visual prognosis, complications and surgical outcomes.

BACKGROUND: Epiretinal membrane (ERM) is a common finding in patients with uveitis that contributes to visual impairment. We describe the long-term visual acuity (VA) and morphometric progression in patients with uveitis and epiretinal membrane (ERM). METHODS: Retrospective cohort study of patients with uveitic ERM from a tertiary centre database. Multivariate analysis of risk factors for ERM progression was calculated using a marginal Cox regression model to estimate hazard ratios (HR). RESULTS: Two hundred and sixteen eyes (4%) of a total 5450 eyes with uveitis were identified to have an ERM. The most common diagnosis was idiopathic uveitis in 45 patients (28.7%), followed by sarcoidosis in 21 (13.4%), HLAB27-related uveitis in 15 (9.6%) and toxoplasmosis in 15 (9.6%). Risk factors for ERM development include age (HR 1.03), intermediate uveitis (HR 2.33), posterior uveitis (HR 1.53) and ERM fellow eye (HR 18.28). Anterior uveitis (HR 0.53) and alternating disease (HR 0.53) were protective. Median VA was 20/40 at diagnosis of ERM and 20/40 at final follow up. Progression of ERM grade occurred in 17 eyes (7.9%) during the study period. ERM peel was performed in 44 eyes (20.4%). Median VA was 20/60 and 20/40 at baseline and 12 months after surgery, respectively. Improvement in visual acuity occurred in 23 eyes (60.5%) following surgery. CONCLUSIONS: In addition to intermediate and posterior uveitis, fellow eye involvement is a strong risk factor for ERM development. In treated uveitis, the majority maintain their long-term vision and rates of ERM progression are low.

Role of Antimicrobial Resistance in Outcomes of Acute Endophthalmitis.

BACKGROUND: This study explores local trends in antimicrobial resistance and its influence on long-term visual outcomes following treatment with broad-spectrum empiric intravitreal antibiotics. METHODS: All patients undergoing intraocular sampling for endophthalmitis from Auckland between January 2006-May 2023 were included. The impact of antimicrobial resistance on the final visual outcome was analysed using logistic regression models. RESULTS: 389 cases of endophthalmitis were included, and 207 eyes (53.2%) were culture positive. When tested, all Gram-positive microorganisms were fully susceptible to Vancomycin, and all Gram-negative microorganisms demonstrated full or intermediate susceptibility to Ceftazidime. Resistance to at least one antimicrobial agent was present in 89 culture results (43.0%), and multidrug resistance (resistant to ≥3 antimicrobials) in 23 results (11.1%). No increase in resistance was observed over time. The primary procedure was a tap and inject in 251 eyes (64.5%), and early vitrectomy was performed in 196 eyes (50.3%). Severe vision loss (≤20/200) occurred in 167 eyes (42.9%). Antimicrobial resistance was associated with an increased risk of retinal detachment (OR 2.455 p = 0.048) but not vision loss (p = 0.288). CONCLUSION: High sensitivity to Vancomycin and Ceftazidime was present in our population, reinforcing their role as first-line empiric treatments. Resistant microorganisms were associated with an increased risk of retinal detachment but no alteration in final visual outcome.

A multi-centre prospective evaluation of THEIA™ to detect diabetic retinopathy (DR) and diabetic macular oedema (DMO) in the New Zealand screening program.

PURPOSE: To validate the potential application of THEIA™ as clinical decision making assistant in a national screening program. METHODS: A total of 900 patients were recruited from either an urban large eye hospital, or a semi-rural optometrist led screening provider, as they were attending their appointment as part of New Zealand Diabetic Eye Screening Programme. The de-identified images were independently graded by three senior specialists, and final results were aggregated using New Zealand grading scheme, which was then converted to referable/non-referable and Healthy/mild/more than mild/sight threatening categories. RESULTS: THEIA™ managed to grade all images obtained during the study. Comparing the adjudicated images from the specialist grading team, "ground truth", with the grading by the AI platform in detecting "sight threatening" disease, at the patient level THEIA™ achieved 100% imageability, 100% [98.49-100.00%] sensitivity and [97.02-99.16%] specificity, and negative predictive value of 100%. In other words, THEIA™ did not miss any patients with "more than mild" or "sight threatening" disease. The level of agreement between the clinicians and the aggregated results was (k value: 0.9881, 0.9557, and 0.9175), and the level of agreement between THEIA™ and the aggregated labels was (k value: 0.9515). CONCLUSION: This multi-centre prospective trial showed that THEIA™ did not miss referable disease when screening for diabetic retinopathy and maculopathy. It also had a very high level of granularity in reporting the disease level. As THEIA™ has been tested on a variety of cameras, operating in a range of clinics (rural/urban, ophthalmologist-led\optometrist-led), we believe that it will be a suitable addition to a public diabetic screening program.

Ethnic differences on long term outcomes of polypoidal choroidal vasculopathy after predominantly bevacizumab monotherapy.

BACKGROUND: A 3-year single-centre, retrospective, comparative, non-randomized cohort study to describe the long-term outcomes of treatment-naïve, Caucasian and non-Caucasian eyes with polypoidal choroidal vasculopathy (PCV) after treatment with predominantly Bevacizumab monotherapy or in combination with rescue photodynamic therapy (PDT). METHODS: Demographics, visual outcomes, optical coherence tomography (OCT) and treatment data were collected up to 3 years after the first visit. Stratified analysis according to ethnicity and baseline vision was performed to identify factors predictive of long-term visual improvement and maintenance. RESULTS: A total of 89 eyes with PCV were identified, of which 14 received rescue verteporfin PDT. There was an equal distribution between Caucasian and non-Caucasian individuals. Non-Caucasians present at a younger age (67.3 vs. 76.0 years, p = 0.002), have a higher proportion of foveal involvement (80.9%, vs.54.2% p = 0.007), choroidal hyperpermeability (50% vs 25.8%, p = 0.013) and lower baseline visual acuity (53.1 vs. 63.3 letters, p = 0.008). Mean visual acuity (VA) gain was + 8.9 letters and + 5.0 letters at 1 and 3 years of follow-up, respectively. Non-Caucasian individuals had a lower mean final visual acuity (VA) (54.7 vs. 70.5, respectively; P < 0.001) and net gain in VA (+ 2.0 vs. + 7.6 letters, p = 0.581) compared to Caucasian individuals. The mean total number of injections given over 3 years was 14. CONCLUSIONS: Most patients treated with predominantly Bevacizumab anti-vascular endothelial growth factor (VEGF) monotherapy achieved sustained visual acuity gains out to 3 years. Due to ethnic-specific differences in presenting PCV phenotypes, non-Caucasians presented with lower baseline VA and had poorer long-term visual outcomes.

Patients Perceptions of Artificial Intelligence in Diabetic Eye Screening.

PURPOSE: Artificial intelligence (AI) technology is poised to revolutionize modern delivery of health care services. We set to evaluate the patient perspective of AI use in diabetic retinal screening. DESIGN: Survey. METHODS: Four hundred thirty-eight patients undergoing diabetic retinal screening across New Zealand participated in a survey about their opinion of AI technology in retinal screening. The survey consisted of 13 questions covering topics of awareness, trust, and receptivity toward AI systems. RESULTS: The mean age was 59 years. The majority of participants identified as New Zealand European (50%), followed by Asian (31%), Pacific Islander (10%), and Maori (5%). Whilst 73% of participants were aware of AI, only 58% have heard of it being implemented in health care. Overall, 78% of respondents were comfortable with AI use in their care, with 53% saying they would trust an AI-assisted screening program as much as a health professional. Despite having a higher awareness of AI, younger participants had lower trust in AI systems. A higher proportion of Maori and Pacific participants indicated a preference toward human-led screening. The main perceived benefits of AI included faster diagnostic speeds and greater accuracy. CONCLUSIONS: There is low awareness of clinical AI applications among our participants. Despite this, most are receptive toward the implementation of AI in diabetic eye screening. Overall, there was a strong preference toward continual involvement of clinicians in the screening process. There are key recommendations to enhance the receptivity of the public toward incorporation of AI into retinal screening programs.

The outcomes of patients with newly diagnosed exudative age-related macular degeneration in Palmerston North.

AIM: To describe the outcomes of patients with newly diagnosed neovascular age-related macular degeneration (nAMD) treated in Palmerston North over the past two years. METHOD: A large prospective database was developed to capture the treatment and visual outcomes of patients with newly diagnosed nAMD. Data were subsequently extracted and analysed according to the result-based accountability (RBA) framework. RESULTS: Fifty-three patients in 2018 and 40 patients in 2019 were identified as having newly diagnosed nAMD. On average, there was an improvement in duration between the date of triage and the first intravitreal injection by eight days (22.7 vs 14.3 days), thus meeting national guidelines to assess and treat new referrals within 14 days. The total number of injections for the 2018 cohort was 227 compared to 301 in 2019. The percentage of patients achieving stabilisation of vision (≤15 letters vision loss, 82.5% vs 93.2%) and improvement in vision (≥15 letters gain, 10.5% vs 31.8%) was higher in 2019 compared to 2018. The percentage of patients that retained driving standard (ie, visual acuity of 6/12) was similar across both years (58.3% vs 62.5%). CONCLUSION: Patients receiving treatment for newly diagnosed nAMD in Palmerston North were achieving high rates of stabilisation and improvements in visual acuity, with more than half maintaining the national driving standard. The locally developed prospective database allows for real-time analysis of patient outcomes and the evaluation of the effectiveness of quality-improvement strategies.

Think about cats in acute vision loss.

Cat-scratch disease (CSD) is a systemic illness caused by the gram-negative bacteria Bartonella henselae (B. henselae). Cats serve as the primary host reservoir for B. henselae, with cat fleas as the horizontal vector of transmission. It is transmitted to humans through close contact with cats and cat scratches and bites. We describe two cases of bilateral Bartonella neuroretinitis that were presented to Palmerston North Hospital Eye Clinic.

Editing of Chloroplast rps14 by PPR Editing Factor EMB2261 Is Essential for Arabidopsis Development.

RNA editing in plastids is known to be required for embryogenesis, but no single editing event had been shown to be essential. We show that the emb2261-2 mutation is lethal through a failure to express an editing factor that specifically recognizes the rps14-2 site. EMB2261 was predicted to bind the cis-element upstream of the rps14-2 site and genetic complementation with promoters of different strength followed by RNA-seq analysis was conducted to test the correlation between rps14-2 editing and EMB2261 expression. Rps14-2 is the only editing event in Arabidopsis chloroplasts that correlates with EMB2261 expression. Sequence divergence between the cis-element and the EMB2261 protein sequence in plants where rps14-2 editing is not required adds support to the association between them. We conclude that EMB2261 is the specificity factor for rps14-2 editing. This editing event converts P51 in Rps14 to L51, which is conserved among species lacking RNA editing, implying the importance of the editing event to Rps14 function. Rps14 is an essential ribosomal subunit for plastid translation, which, in turn, is essential for Arabidopsis embryogenesis.

Predictable alteration of sequence recognition by RNA editing factors from Arabidopsis.

RNA editing factors of the pentatricopeptide repeat (PPR) family show a very high degree of sequence specificity in the recognition of their target sites. A molecular basis for target recognition by editing factors has been proposed based on statistical correlations but has not been tested experimentally. To achieve this, we systematically mutated the pentatricopeptide motifs in the Arabidopsis thaliana RNA editing factor CLB19 to investigate their individual contribution to RNA recognition. We find that the motifs contributing significantly to the specificity of binding follow the previously proposed recognition rules, distinguishing primarily between purines and pyrimidines. Our results are consistent with proposals that each motif recognizes one nucleotide in the RNA target with the protein aligned parallel to the RNA and contiguous motifs aligned with contiguous nucleotides such that the final PPR motif aligns four nucleotides upstream of the edited cytidine. By altering S motifs in CLB19 and another editing factor, OTP82, and using the modified proteins to attempt to complement the respective mutants, we demonstrate that we can predictably alter the specificity of these factors in vivo.

AEF1/MPR25 is implicated in RNA editing of plastid atpF and mitochondrial nad5, and also promotes atpF splicing in Arabidopsis and rice.

RNA editing is an essential mechanism that modifies target cytidines to uridine in both mitochondrial and plastid mRNA. Target sites are recognized by pentatricopeptide repeat (PPR) proteins. Using bioinformatics predictions based on the code describing sequence recognition by PPR proteins, we have identified an Arabidopsis editing factor required for editing of atpF in plastids. A loss-of-function mutation in ATPF EDITING FACTOR 1 (AEF1, AT3G22150) results in severe variegation, presumably due to decreased plastid ATP synthase levels. Loss of editing at the atpF site is coupled with a large decrease in splicing of the atpF transcript, even though the editing site is within an exon and 53 nucleotides distant from the splice site. The rice orthologue of AEF1, MPR25, has been reported to be required for editing of a site in mitochondrial nad5 transcripts, and we confirm that editing of the same site is affected in the Arabidopsis aef1 mutant. We also show that splicing of chloroplast atpF transcripts is affected in the rice mpr25 mutant. AEF1 is thus highly unusual for an RNA editing specificity factor in that it has functions in both organelles.

A combinatorial amino acid code for RNA recognition by pentatricopeptide repeat proteins.

The pentatricopeptide repeat (PPR) is a helical repeat motif found in an exceptionally large family of RNA-binding proteins that functions in mitochondrial and chloroplast gene expression. PPR proteins harbor between 2 and 30 repeats and typically bind single-stranded RNA in a sequence-specific fashion. However, the basis for sequence-specific RNA recognition by PPR tracts has been unknown. We used computational methods to infer a code for nucleotide recognition involving two amino acids in each repeat, and we validated this model by recoding a PPR protein to bind novel RNA sequences in vitro. Our results show that PPR tracts bind RNA via a modular recognition mechanism that differs from previously described RNA-protein recognition modes and that underpins a natural library of specific protein/RNA partners of unprecedented size and diversity. These findings provide a significant step toward the prediction of native binding sites of the enormous number of PPR proteins found in nature. Furthermore, the extraordinary evolutionary plasticity of the PPR family suggests that the PPR scaffold will be particularly amenable to redesign for new sequence specificities and functions.

The Arabidopsis gene YS1 encoding a DYW protein is required for editing of rpoB transcripts and the rapid development of chloroplasts during early growth.

Virescence, a phenotype in which leaves green more slowly than usual, is recognized to play a role in protection from photo-oxidative damage before healthy chloroplasts are developed. The elucidation of the molecular mechanisms underlying virescence will provide insights into how the development of chloroplasts is controlled. In this study, we find that knockout alleles of Yellow Seedlings 1 (YS1) in Arabidopsis lead to a virescent phenotype, which disappears by 3 weeks after germination. The ys1 mutation resulted in marked decreases in photosynthetic capacity and photosynthetic pigment complexes, and disturbed ultrastructure of thylakoid membranes in 8-day-old seedlings. However, cotyledons of ys1 seedlings pre-treated in the dark for 5 days turn green almost as fast as the wild type in light, revealing that the developmental defects in ys1 are limited to the first few days after germination. Inspection of all known plastid RNA editing and splicing events revealed that YS1 is absolutely required for editing of site 25992 in rpoB transcripts encoding the beta subunit of the plastid-encoded RNA polymerase (PEP). YS1 is a nuclear-encoded chloroplast-localized pentatricopeptide repeat protein differing from previously described editing factors in that it has a C-terminal DYW motif. A defect in PEP activity is consistent with the changes in plastid transcript patterns observed in ys1 seedlings. We conclude that the activity of PEP containing RpoB translated from unedited transcripts is insufficient to support rapid chloroplast differentiation.