Transcribed intergenic regions exhibit a lower frequency of nucleotide polymorphism than the untranscribed intergenic regions in the genomes of Escherichia coli and Salmonella enterica.

The temporary exposure of single-stranded regions in the genome during the process of replication and transcription makes the region vulnerable to cytosine deamination resulting in a higher rate of C→T transition. Intraoperon intergenic regions undergo transcription along with adjacent co-transcribed genes in an operon, whereas interoperon intergenic regions are usually devoid of transcription. Hence these two types of intergenic regions (IGRs) can be compared to find out the contribution of replication-associated mutations (RAM) and transcription-associated mutations (TrAM) towards bringing variation in genomes. In our work, we performed a polymorphism spectra comparison between intraoperon IGRs and interoperon IGRs in genomes of two well-known closely related bacteria such as Escherichia coli and Salmonella enterica. In general, the size of intraoperon IGRs was smaller than that of interoperon IGRs in E. coli and S. enterica. Interestingly, the polymorphism frequency at intraoperon IGRs was 2.5-fold lesser than that in the interoperon IGRs in E. coli genome. Similarly, the polymorphism frequency at intraoperon IGRs was 2.8-fold lesser than that in the inter-operon IGRs in S. enterica genome. Therefore, the intraoperon IGRs were often observed to be more conserved. In the case of interoperon IGRs, the T→C transition frequency was a minimum of two times more frequent than T→A transversion frequency whereas in the case of intraoperon IGRs, T→C transition frequency was similar to that of T→A transversion frequency. The polymorphism was purine-biased and keto-biased more in intraoperon IGRs than the inter-operon IGRs. In E. coli, the transition/transversion ratio was observed as 1.639 and 1.338 in inter-operon and in intraoperon IGRs, respectively. In S. enterica, the transition/transversion ratio was observed as 2.134 and 2.780 in inter-operon and in intraoperon IGRs, respectively. The observation in this study indicates that transcribable IGRs might not always have higher polymorphism frequency than nontranscribable IGRs. The lower polymorphism frequency at intraoperon IGRs might be attributed to different events such as the transcription-coupled DNA repair, sequences facilitating translation initiation and avoidance of Rho-dependent transcription termination.

Incorporation of transition to transversion ratio and nonsense mutations, improves the estimation of the number of synonymous and non-synonymous sites in codons.

A common approach to estimate the strength and direction of selection acting on protein coding sequences is to calculate the dN/dS ratio. The method to calculate dN/dS has been widely used by many researchers and many critical reviews have been made on its application after the proposition by Nei and Gojobori in 1986. However, the method is still evolving considering the non-uniform substitution rates and pretermination codons. In our study of SNPs in 586 genes across 156 Escherichia coli strains, synonymous polymorphism in 2-fold degenerate codons were higher in comparison to that in 4-fold degenerate codons, which could be attributed to the difference between transition (Ti) and transversion (Tv) substitution rates where the average rate of a transition is four times more than that of a transversion in general. We considered both the Ti/Tv ratio, and nonsense mutation in pretermination codons, to improve estimates of synonymous (S) and non-synonymous (NS) sites. The accuracy of estimating dN/dS has been improved by considering the Ti/Tv ratio and nonsense substitutions in pretermination codons. We showed that applying the modified approach based on Ti/Tv ratio and pretermination codons results in higher values of dN/dS in 29 common genes of equal reading-frames between E. coli and Salmonella enterica. This study emphasizes the robustness of amino acid composition with varying codon degeneracy, as well as the pretermination codons when calculating dN/dS values.

Machine learning approach identifies prominent codons from different degenerate groups influencing gene expression in bacteria.

Unequal usage of synonymous codons is known as codon usage bias (CUB), which is generally different between the high-expression genes (HEG) and low-expression genes (LEG) in organisms is not yet adequately reported across different bacteria. In this study, a machine learning-based approach was implemented initially to find out codons that are significantly different between the HEG and LEG in Escherichia coli. It identified Cys codons such as UGU and UGC, Lys codons such as AAA and AAG that were least influenced by gene expression. Codons such as UCU (Ser), CUG (Leu), GGG (Gly), CGG (Arg) etc. were identified to be influenced maximum by the gene expression. The study was extended to analyze codon usage in 683 other bacterial species. Cys (UGU/UGC) and Ser (AGU/AGC) codons were identified being the least different between the two groups of genes across these bacterial species. Codons such as CGA, CUG, GGG, GCC, ACC, AUA, and AUC were identified to be influenced by the gene expression across majority of these species. This study supports the role of CUB on gene expression across bacteria and demonstrates a commonality among bacteria regarding behavior of certain codons with regard to gene expression.

Correlation of Optical Coherence Tomography Angiography Characteristics with Visual Function to Define Vision-Threatening Diabetic Macular Ischemia.

The thresholds of macular microvasculature parameters associated with mild visual impairment in diabetic macular ischemia (DMI) patients are unclear. Therefore, this prospective observational study is aimed at demonstrating the optical coherence tomography angiography parameters that best correlate with mild visual impairment (<70 Early Treatment Diabetic Retinopathy Study (ETDRS) letters, Snellen equivalent 20/40) in DMI. The study was completed at the Moorfields Eye Hospital from December 2019 to August 2021. A total of 123 eyes of 87 patients with stable-treated proliferative diabetic retinopathy following panretinal photocoagulation were recruited. DMI was defined as an irregular foveal avascular zone (FAZ) area ≥ 0.5 mm2 or a smaller FAZ area with parafoveal capillary dropout in at least one quadrant. The analysis showed that the whole image deep vascular complex vessel density (DVC VD) in the 3 × 3 mm area had the best discriminatory ability to identify participants with mild visual impairment at 41.9% (area under the curve = 0.77, sensitivity 94%, specificity 54%, likelihood ratio [LR] = 2.04), and the FAZ area had the greatest post-test LR = 4.21 at 0.64 mm2. The 3 × 3 mm whole image DVC VD and FAZ area cutoffs are useful for screening vision-threatening DMI, but DVC VD has low specificity.

RETINAL NONPERFUSION IN THE EARLY TREATMENT DIABETIC RETINOPATHY STUDY SEVEN FIELDS COMPARED WITH WIDEFIELD FLUORESCEIN ANGIOGRAPHY: Correlation and Use of Extrapolation Factor.

BACKGROUND: In previous landmark studies on central retinal vein occlusion, retinal nonperfusion assessments were obtained using 7-field (7F) angiography. The widespread current use of widefield imaging allows better visualization of the peripheral retina and more comprehensive estimation of the total area of nonperfusion. The relationship between nonperfusion measurement of 7F and widefield angiography (WFA) in central retinal vein occlusion has not been studied. We aim to identify the correlation of retinal nonperfusion measured within the 7F and on WFA in eyes with central retinal vein occlusion. METHODS: Retinal nonperfusion in participants with central retinal vein occlusion was determined using a 7F Early Treatment Diabetic Retinopathy Study template and the concentric rings method. RESULTS: A total of 153 eyes were included. Pearson correlation test showed a near-perfect positive, linear correlation between the nonperfusion found in the 7F and total retinal nonperfusion on WFA (0.985 95% CI [0.793, 0.999]) The regression line equation for nonperfusion on 7F and WFA was y = 37 + 3.2x. Eyes with 0 disk areas (DA), >0 DA to 10 DA and >10 DA of nonperfusion on 7-fields had on average 23 DA 95% CI (19.20, 27.06), 45 DA 95% CI (35.75, 55.18), and 115 DA 95% CI (88.89, 142.05) on widefield respectively. CONCLUSION: There is a positive and linear relationship between nonperfusion measured by 7F and WFA in central retinal vein occlusion with more than 3-times the amount of nonperfusion identified on WFA. Despite <10 DA no areas of nonperfusion on 7F, there is typically at least 35 DA of nonperfusion on WFA whereas eyes with >10 DA of nonperfusion on 7F had at least 88 DA on WFA.

Visual Outcomes Associated With Patterns of Macular Edema Resolution in Central Retinal Vein Occlusion Treated With Anti-Vascular Endothelial Growth Factor Therapy: A Post Hoc Analysis of the Lucentis, Eylea, Avastin in Vein Occlusion (LEAVO) Trial.

IMPORTANCE: It is unclear how visual outcomes vary between patterns of macular edema (ME) resolution in eyes with central retinal vein occlusion (CRVO). OBJECTIVE: To assess best-corrected visual acuity (BCVA) outcomes at 100 weeks based on macular fluid resolution patterns by 52 and 100 weeks among patients receiving anti-vascular endothelial growth factor therapy for CRVO-related ME. DESIGN, SETTING, AND PARTICIPANTS: Post hoc analysis of the prospective, 3-arm, double-masked, randomized noninferiority trial Lucentis, Eylea, Avastin in Vein Occlusion (LEAVO), which evaluated intravitreal aflibercept (2.0 mg/0.05 mL), bevacizumab (1.25-mg/0.05 mL), or ranibizumab (0.5 mg/0.05 mL) over 100 weeks in adult patients (18 years and older) with CRVO-related ME with BCVA Early Treatment Diabetic Retinopathy Study (ETDRS) letter score of 19 to 78 in the study eye (approximate Snellen equivalent, 20/400 to 20/32, respectively) from December 2014 to December 2016 at 44 UK National Health Service ophthalmology departments. A total of 140 of 154 eyes were randomized to aflibercept, 144 of 154 randomized to bevacizumab, and 141 of 155 randomized to ranibizumab. Data were analyzed from January 2019 to March 2019. EXPOSURES: Persistent ME included eyes with central subfield thickness (CST) 320 µm or greater, and persistently dry macula (no ME) included eyes with CST less than 320 µm at 52 and 100 weeks. Recurrent ME included eyes that did not meet the criteria for persistently dry or wet. If CST was missing, the closest intervening visit was carried forward. MAIN OUTCOMES AND MEASURES: Adjusted mean BCVA at 100 weeks. RESULTS: The mean (SD) age of the 425 included participants was 69.2 (12.7) years, and 243 participants (57.2%) were men. A total of 425 eyes from 425 participants were included. By 100 weeks, 117 eyes (28.5%) were persistently dry, 44 (10.7%) were persistently wet (with ME), and 250 (60.8%) had recurrent ME. Persistent ME at 100 weeks was associated with worse VA compared with dry macula (adjusted difference, -10.98 ETDRS letters; 95% CI, -16.19 to -5.76; P < .001) and recurrent ME (adjusted difference, -5.39 letters; 95% CI, -10.15 to -0.64; P = .03). By 52 weeks, individuals with persistent ME also had poorer 100-week BCVA compared with individuals with dry macula (adjusted difference, -7.39; 95% CI, -11.72 to -3.05; P < .001) and recurrent ME (adjusted difference, -3.92; 95% CI, -8.05 to 0.20; P = .06). By 100 weeks, more eyes treated with bevacizumab had persistently wet macula than those treated with aflibercept (26 of 140 [18.6%] vs 7 of 134 [5.2%]; difference, 13.3%; 95% CI, 5.9 to 20.8; P < .001) or ranibizumab (11 of 137 [8%]; difference, 10.5%; 95% CI, 2.7 to 18.4; P = .01). CONCLUSIONS AND RELEVANCE: These findings suggest that attempts should be made to maintain persistently fluid-free macula for optimal visual acuity outcomes.

Stem Region of tRNA Genes Favors Transition Substitution Towards Keto Bases in Bacteria.

Transversion and transition mutations have variable effects on the stability of RNA secondary structure considering that the former destabilizes the double helix geometry to a greater extent by introducing purine:purine (R:R) or pyrimidine:pyrimidine (Y:Y) base pairs. Therefore, transversion frequency is likely to be lower than that of transition in the secondary structure regions of RNA genes. Here, we performed an analysis of transition and transversion frequencies in tRNA genes defined well with secondary structure and compared with the intergenic regions in five bacterial species namely Escherichia coli, Klebsiella pneumoniae, Salmonella enterica, Staphylococcus aureus and Streptococcus pneumoniae using a large genome sequence data set. In general, the transversion frequency was observed to be lower than that of transition in both tRNA genes and intergenic regions. The transition to transversion ratio was observed to be greater in tRNA genes than that in the intergenic regions in all the five bacteria that we studied. Interestingly, the intraspecies base substitution analysis in tRNA genes revealed that non-compensatory substitutions were more frequent than compensatory substitutions in the stem region. Further, transition to transversion ratio in the loop region was observed to be significantly lesser than that among the non-compensatory substitutions in the stem region. This indicated that the transversion is more deleterious than transition in the stem regions. In addition, substitutions from amino bases (A/C) to keto bases (G/T) were also observed to be more than the reverse substitutions in the stem region. Substitution from amino bases to keto bases are likely to facilitate the stable G:U pairing unlike the reverse substitution that facilitates the unstable A:C pairing in the stem region of tRNA. This work provides additional support that the secondary structure of tRNA molecule is what drives the different substitutions in its gene sequence.

Long-term follow-up of a case of posterior microphthalmos (PRSS56) with hyperautofluorescent retinal pigment epithelial deposits.

PURPOSE: To report a case of posterior microphthalomos (PM) related to PRSS56 gene mutation with long term follow up with multimodal imaging findings. METHODS: Single retrospective case report. RESULTS: A 43-year old male patient presented in 2009 with bilateral reduced vision. Clinical examination and multimodal imaging showed features consistent with posterior microphthalmos with prominent bilateral horizontal papillomacular retinal folds. Posterior pole hyperautofluorescent RPE deposits were present. Gradual worsening of visual acuity and rod and cone photoreceptor function more so on the left was demonstrated during the 8 years of follow up. CONCLUSION: Hyperautofluorescent RPE deposits may occur in patients with posterior microphthalmos and such patient's may experience only gradual disease progression over long term follow up.

Inter-rater reliability for diagnosis of geographic atrophy using spectral domain OCT in age-related macular degeneration.

PURPOSE: To evaluate the inter-rater reliability for identification of complete retinal pigment epithelium and outer retinal atrophy (cRORA) on SD-OCT images as defined by the Classification of Atrophy Meetings (CAM) group. METHODS: Fifty images of anonymized SD-OCT line scans of eyes with cRORA due to AMD were selected. Each .tiff image was saved in both black-on-white (BW) and white-on-black (WB) format. Five retina-trained clinicians graded both sets of images twice for the diagnosis of cRORA based on the CAM group definition. Fleiss kappa statistic was calculated for inter-rater reliability and Cohen's kappa statistic for intra-grader and inter-grader reliability between any two graders. RESULTS: The inter-grader reliability varied from as low as 0.28 to 0.92 for WB images and 0.34 to 0.86 for BW images. However, the inter-grader and intra-grader agreement was ĸ WB 0.92; ĸ BW 0.86 and ĸ 0.92 respectively, for graders accustomed to the CAM criteria. Fleiss kappa was ĸ 0.49 (p value < 0.0001) for WB images and ĸ 0.34 (p value < 0.0001 for BW images. Overall, the agreement was better using WB images for all parameters except RPE attenuation/loss. CONCLUSION: There is significant variability in diagnosis of cRORA on SD-OCT by retina-trained ophthalmologists in the real world. The study highlights the need for training to recognise the different features of cRORA prior to its implementation in clinical practice.

Functional clinical endpoints and their correlations in eyes with AMD with and without subretinal drusenoid deposits-a pilot study.

PURPOSE: To evaluate functional clinical endpoints and their structural correlations in AMD, with a focus on subretinal drusenoid deposits (SDD). METHODS: This prospective study enroled 50 participants (11 controls, 17 intermediate AMD (iAMD) with no SDD, 11 iAMD with SDD and 11 non-foveal atrophic AMD). Participants underwent best-corrected visual acuity (BCVA), low luminance visual acuity (LLVA), low luminance questionnaire (LLQ), scotopic thresholds, rod-intercept time (RIT), photopic flicker electroretinograms and multimodal imaging. Functional and structural relationships were assessed. RESULTS: Compared with healthy participants, BCVA, LLVA, scotopic thresholds were depressed, and RIT prolonged in iAMD patients with SDD (p = 0.028, p = 0.045, p = 0.014 and p < 0.0001 respectively). Patients with SDD also had reduced scotopic function and delayed RIT compared to iAMD without SDD (p = 0.005 and p < 0.0001). Eyes with SDD and non-foveal atrophy did not differ functionally. Nor did healthy subjects compared with iAMD without SDD. Functional parameters were significantly associated with scotopic thresholds (r = 0.39-0.64). BCVA, LLVA and scotopic thresholds correlated well with ONL volume, ONL thickness and choroidal thickness (r = 0.34-0.61). CONCLUSION: Eyes with SDD are surrogate markers of photoreceptor abnormalities comparable with non-central atrophy and should be sub-analysed in clinical trials evaluating potential prophylactic agents to decrease the progression of AMD and may even require different therapeutic interventions.

The clinical relevance of ultra-widefield angiography findings in patients with central retinal vein occlusion and macular oedema receiving anti-VEGF therapy.

AIMS: To report, using ultra-widefield angiography (UWFA) the area, distribution, and change in retinal capillary nonperfusion (RCNP) at baseline and 100 weeks in eyes with central retinal vein occlusion (CRVO) receiving anti-VEGF for macula oedema. METHODS: Prospective longitudinal multi-centre cohort study. Adults with CRVO treated with anti-VEGF therapy for macular oedema underwent UWFA at baseline and week-100. The area, distribution, and change in total, peripheral and posterior pole RCNP were determined. RESULTS: Of 153 eyes at baseline, mean area of RCNP was 34.3DA and 12 (7.8%) had ≥75DA RCNP. More than 10DA RCNP was present in the temporal periphery in 75.8% of eyes vs. 10.5% in the nasal periphery. At week-100, mean RCNP was 42.1DA with a median change from baseline of 3.3DA 95% CI [0.4, 7.3]; p < 0.01. Of 146 eyes with ≤10DA of posterior pole RCNP at baseline, 16/146 (11.0%) progressed to >10DA at week-100. These eyes had a median increase in total RCNP of 69.7DA [95% CI 27.2-85.4] vs 0DA [0.0-1.4]; p < 0.001 for those who did not, and two developed neovascular glaucoma. Larger baseline area of RCNP and history of glaucoma were risk factors for posterior pole RCNP developing. CONCLUSIONS: With UWFA, significant baseline RCNP was identified in the majority of CRVO patients, notably in the temporal periphery, but large increases over 100 weeks were uncommon. Development of >10DA posterior pole RCNP is a marker for widespread RCNP and in such cases the risk of anterior segment neovascularisation is not abolished by concomitant anti-VEGF therapy.

Outcomes of neovascular glaucoma in eyes presenting with moderate to good visual potential.

PURPOSE: To compare the disease characteristics and treatment outcomes of patients with neovascular glaucoma (NVG) presenting with visual acuity (VA) 6/60 or better in two different health systems. METHODS: Retrospective chart review of consecutive patients with NVG who presented between January 2016 to January 2018 in 5 tertiary-centres in India and one eye-specialist centre in London (UK) was performed. The baseline characteristics, treatment provisions, and visual outcomes in the India and UK cohorts were compared. RESULTS: At presentation, 18% (83 of 451) and 22% (59 of 270) of patients with NVG had VA 6/60 or better in India and the UK cohorts, respectively. The aetiologies of NVG were similar with proliferative diabetic retinopathy being the most common cause (60.9%, India; 64.4%, UK; p = 0.38). Previous panretinal photocoagulation was more prevalent in the UK cohort compared to the India cohort (94.9% versus 66.3%, respectively; p < 0.001). The mean number of intravitreal anti-VEGF injections per eye was higher in the Indian cohort (1.65 ± 0.97 versus 1.14 ± 1.02 injections; p < 0.001). The number of eyes with closed angles (36.9% India versus 30.5% UK; p = 0.45) and the number of eyes needing glaucoma interventions (52.1% India; 62.7% UK; p = 0.82) were similar in two cohorts. Among glaucoma surgeries, trabeculectomies were more commonly performed in the Indian cohort (23 vs 4; p < 0.001),while glaucoma drainage device surgeries were more prevalent in the UK cohort (18 vs 4 p < 0.001). After a median follow-up of 21 months (IQR 8.4-34.8 India; 24-36 months UK), favourable visual outcomes (vision stable or improved) were similar in both health systems (52.5% in the Indian cohort vs 43.4% in the UK cohort; p = 0.28). On multivariate regression analysis, the need for trans-scleral cyclophotocoagulation was associated with worse visual outcomes in both cohorts. CONCLUSIONS: The causes and clinical profile of neovascular glaucoma with presenting visual acuity 6/60 or better in India and the UK were similar. Only up to 50% of eyes achieved favourable visual outcomes with current management protocols in both health systems.

Detection of Diabetic Retinopathy from Ultra-Widefield Scanning Laser Ophthalmoscope Images: A Multicenter Deep Learning Analysis.

PURPOSE: To develop a deep learning (DL) system that can detect referable diabetic retinopathy (RDR) and vision-threatening diabetic retinopathy (VTDR) from images obtained on ultra-widefield scanning laser ophthalmoscope (UWF-SLO). DESIGN: Observational, cross-sectional study. PARTICIPANTS: A total of 9392 UWF-SLO images of 1903 eyes from 1022 subjects with diabetes from Hong Kong, the United Kingdom, India, and Argentina. METHODS: All images were labeled according to the presence or absence of RDR and the presence or absence of VTDR. Labeling was performed by retina specialists from fundus examination, according to the International Clinical Diabetic Retinopathy Disease Severity Scale. Three convolutional neural networks (ResNet50) were trained with a transfer-learning procedure for assessing gradability and identifying VTDR and RDR. External validation was performed on 4 datasets spanning different geographical regions. MAIN OUTCOME MEASURES: Area under the receiver operating characteristic curve (AUROC); area under the precision-recall curve (AUPRC); sensitivity, specificity, and accuracy of the DL system in gradability assessment; and detection of RDR and VTDR. RESULTS: For gradability assessment, the system achieved an AUROC of 0.923 (95% confidence interval [CI], 0.892-0.947), sensitivity of 86.5% (95% CI, 77.6-92.8), and specificity of 82.1% (95% CI, 77.3-86.2) for the primary validation dataset, and >0.82 AUROCs, >79.6% sensitivity, and >70.4% specificity for the geographical external validation datasets. For detecting RDR and VTDR, the AUROCs were 0.981 (95% CI, 0.977-0.984) and 0.966 (95% CI, 0.961-0.971), with sensitivities of 94.9% (95% CI, 92.3-97.9) and 87.2% (95% CI, 81.5-91.6), specificities of 95.1% (95% CI, 90.6-97.9) and 95.8% (95% CI, 93.3-97.6), and positive predictive values (PPVs) of 98.0% (95% CI, 96.1-99.0) and 91.1% (95% CI, 86.3-94.3) for the primary validation dataset, respectively. The AUROCs and accuracies for detecting both RDR and VTDR were >0.9% and >80%, respectively, for the geographical external validation datasets. The AUPRCs were >0.9, and sensitivities, specificities, and PPVs were >80% for the geographical external validation datasets for RDR and VTDR detection. CONCLUSIONS: The excellent performance achieved with this DL system for image quality assessment and detection of RDR and VTDR in UWF-SLO images highlights its potential as an efficient and effective diabetic retinopathy screening tool.

Looking Ahead: Visual and Anatomical Endpoints in Future Trials of Diabetic Macular Ischemia.

Diabetic macular ischemia (DMI) is a common complication of diabetic retinopathy that can lead to progressive and irreversible visual loss. Despite substantial clinical burden, there are no treatments for DMI, no validated clinical trial endpoints, and few clinical trials focusing on DMI. Therefore, generating consensus on validated endpoints that can be used in DMI for the development of effective interventions is vital. In this review, we discuss potential endpoints appropriate for use in clinical trials of DMI, and consider the data required to establish acceptable and meaningful endpoints. A combination of anatomical, functional, and patient-reported outcome measures will provide the most complete picture of changes that occur during the progression of DMI. Potential endpoint measures include change in size of the foveal avascular zone measured by optical coherence tomography angiography and change over time in best-corrected visual acuity. However, these endpoints must be supported by further research. We also recommend studies to investigate the natural history and progression of DMI. In addition to improving understanding of how patient demographics and comorbidities such as diabetic macular edema affect clinical trial endpoints, these studies would help to build the consensus definition of DMI that is currently missing from clinical practice and research.

Predictors of Visual Acuity Outcomes after Anti-Vascular Endothelial Growth Factor Treatment for Macular Edema Secondary to Central Retinal Vein Occlusion.

PURPOSE: To evaluate whether baseline demographic, clinical, and OCT characteristics predict visual acuity (VA) outcomes in patients receiving anti-vascular endothelial growth factor (VEGF) therapy for macular edema (ME) due to central retinal vein occlusion (CRVO). DESIGN: Post hoc analysis of the randomized noninferiority trial (Lucentis, Eylea, Avastin in CRVO) LEAVO Study from December 12, 2014, to December 16, 2016, carried out across 44 UK National Health Service ophthalmology departments. PARTICIPANTS: Data on 267 participants with a baseline best-corrected mean visual acuity (BCVA) range of 19 to 78 Early Treatment Diabetic Retinopathy Study letter score (approximate Snellen equivalent, 20/32 to 20/320) who had central subfield thickness (CST) ≥ 320 µm on Spectralis OCT (Heidelberg Engineering) were analyzed. METHODS: Study participants were randomized to receive repeated intravitreal injections of ranibizumab (0.5 mg/50 µl), aflibercept (2.0 mg/50 µl), or bevacizumab (1.25 mg/50 µl), and a protocol-driven pro re nata re-treatment regimen at 4 to 8 weekly visits was followed up to week 100 after 4 mandated 4-weekly loading injections. MAIN OUTCOME MEASURES: Change in BCVA and percentage of patients gaining ≥ 10 letters and achieving BCVA letter score > 70 letters at 52 and 100 weeks. RESULTS: The analysis was adjusted for treatment effects and confirmed by sensitivity analysis. Age ≥ 75 years is a poor predictor for all 3 visual outcomes. Lower baseline BCVA predicted 10-letter gainers and higher gains in BCVA, although it is a poor predictor of achieving > 70 Early Treatment Diabetic Retinopathy Study letters. None of the baseline OCT morphologic characteristics except ellipsoid zone (EZ) integrity influenced any visual outcomes. Both baseline CST and total macular volume showed a nonlinear relation to 10-letter gainers, with CST > 900 µm being a poor prognostic indicator. Baseline CST and macular volume did not predict mean change in BCVA or BCVA > 70 letters at 52 and 100 weeks. The sensitivity analysis conclusions after removing iCRVO were similar. CONCLUSIONS: At presentation, younger age, higher baseline BCVA, and a definitely intact subfoveal EZ are predictors of BCVA score > 70 letters at 100 weeks.

Low Luminance Visual Acuity and Low Luminance Deficit in Proliferative Diabetic Retinopathy.

This study aimed to determine the relation of best corrected visual acuity (BCVA) and low luminance visual acuity (LLVA) in proliferative diabetic retinopathy (PDR) following treatment with either aflibercept or pan-retinal photocoagulation (PRP). The study was conducted as a post-hoc analysis of the CLARITY trial in which naïve and PRP treated PDR patients were randomised to receive either aflibercept or PRP. BCVA and LLVA were assessed at baseline and at week 52. Our analyses showed that the BCVA and LLVA correlate well in treatment naïve PDR with an average low luminance deficit of 11.79 Early Treatment Diabetic Retinopathy Score (ETDRS) letters. However, LLVA at lower levels of BCVA showed more variance. Post aflibercept therapy, the mean change in BCVA and LLVA at 52 weeks after aflibercept was +2.1 (SD 6.05) letters and +0.39 (SD 5.6) letters, respectively. Similarly, after PRP, it was -2.5 (SD 4.9) letters and -1.9 (SD 8.7) letters, respectively. When comparing treatment arms, BCVA change was found to be statistically significant (p < 0.001) whereas LLVA was not (p = 0.11). These findings show that LLVA does not respond as well as BCVA following any treatment for PDR, even though BCVA and LLVA both test foveal function.

Deep Learning-Based Segmentation and Quantification of Retinal Capillary Non-Perfusion on Ultra-Wide-Field Retinal Fluorescein Angiography.

Reliable outcome measures are required for clinical trials investigating novel agents for preventing progression of capillary non-perfusion (CNP) in retinal vascular diseases. Currently, accurate quantification of topographical distribution of CNP on ultrawide field fluorescein angiography (UWF-FA) by retinal experts is subjective and lack standardisation. A U-net style network was trained to extract a dense segmentation of CNP from a newly created dataset of 75 UWF-FA images. A subset of 20 images was also segmented by a second expert grader for inter-grader reliability evaluation. Further, a circular grid centred on the FAZ was used to provide standardised CNP distribution analysis. The model for dense segmentation was five-fold cross-validated achieving area under the receiving operating characteristic of 0.82 (0.03) and area under precision-recall curve 0.73 (0.05). Inter-grader assessment on the 20 image subset achieves: precision 59.34 (10.92), recall 76.99 (12.5), and dice similarity coefficient (DSC) 65.51 (4.91), and the centred operating point of the automated model reached: precision 64.41 (13.66), recall 70.02 (16.2), and DSC 66.09 (13.32). Agreement of CNP grid assessment reached: Kappa 0.55 (0.03), perfused intraclass correlation (ICC) 0.89 (0.77, 0.93), non-perfused ICC 0.86 (0.73, 0.92), inter-grader agreement of CNP grid assessment values are Kappa 0.43 (0.03), perfused ICC 0.70 (0.48, 0.83), non-perfused ICC 0.71 (0.48, 0.83). Automated dense segmentation of CNP in UWF-FA images achieves performance levels comparable to inter-grader agreement values. A grid placed on the deep learning-based automatic segmentation of CNP generates a reliable and quantifiable method of measurement of CNP, to overcome the subjectivity of human graders.

Profitability, energetics and GHGs emission estimation from rice-based cropping systems in the coastal saline zone of West Bengal, India.

This study compares thirteen rice-based cropping systems in the coastal part of West Bengal, India in terms of productivity, profitability, energetics, and emissions. Information on the crop management practices of these systems was collected on 60 farms through a questionnaire survey. Rice-bitter gourd system was observed to have the highest system yield (49.88 ± 4.34 tha-1yr-1) followed by rice-potato-ridge gourd (37.78 ± 2.77 tha-1yr-1) and rice-potato-pumpkin (36.84 ± 2.04 tha-1yr-1) systems. The rice-bitter gourd system also recorded the highest benefit:cost ratio (3.92 ± 0.061). The lowest system yield and economics were recorded in the rice-fallow-fallow system. Rice-sunflower system recorded highest specific energy (2.54 ± 0.102 MJkg-1), followed by rice-rice (2.14 ± 0.174 MJkg-1) and rice-fallow-fallow (1.91 ± 0.327 MJkg-1) systems, lowest being observed in the rice-bitter gourd (0.52 ± 0.290 MJkg-1) and rice-pointed gourd (0.52 ± 0.373 MJkg-1) systems. Yield-scaled GHGs (YSGHG) emission was highest (1.265 ± 0.29 t CO2eqt-1 system yield) for rice-fallow-fallow system and was lowest for rice-vegetable systems. To estimate the uncertainty of the YSGHG across different systems under study, Monte-Carlo Simulation was performed. It was observed that there was a 5% probability of recording YSGHG emission > 1.15 t CO2eqt-1 system yield from different cropping systems in the present experiment. Multiple system properties such as productivity, economics, energy, and emission from all rice-based systems taken together, the rice-vegetable system performed consistently well across parameters and may be practised for higher economic returns with judicious and sustainable utilization of resources in the coastal saline tracts of the region.