PREDICTORS AND IMPORTANCE OF COMPLETE POLYPOIDAL LESION REGRESSION IN THE EVEREST II STUDY: Predictors of Polyp Regression in Polypoidal Choroidal Vasculopathy.

PURPOSE: To evaluate the predictors of complete polypoidal lesion regression (CPREG) in polypoidal choroidal vasculopathy. METHODS: Post hoc analysis of EVEREST II-a 24-month, multicenter, randomized, controlled clinical trial of 322 patients with polypoidal choroidal vasculopathy, randomized to receive ranibizumab with or without photodynamic therapy. Images of indocyanine green angiography (ICGA) were graded by a central reading center. Multiple logistic regression analysis with significant baseline predictors then was conducted to assess adjusted odds ratios for CPREG at month (M) 12. RESULTS: Baseline ICGA characteristics were comparable between the treatment groups. Patients treated with combination therapy had higher odds of achieving CPREG at M12 (adjusted odds ratio = 4.64; 95% confidence interval, 2.85-7.55; P < 0.001) compared with those in the monotherapy group. Absence of polypoidal lesion pulsation on ICGA was also associated with CPREG at M12 (adjusted odds ratio = 2.62; 95% confidence interval, 1.32-5.21; P = 0.006). The presence of CPREG at M3 had higher odds of maintaining CPREG at M12 (adjusted odds ratio = 6.60; 95% confidence interval, 3.77-11.57; P < 0.001) compared with those with persistent polypoidal lesions. CONCLUSION: At M12, treatment with combination therapy was associated with higher probability of achieving CPREG than with ranibizumab monotherapy. The results contribute to the further understanding of the response of polypoidal lesions to treatment.

Incomplete Retinal Pigment Epithelial and Outer Retinal Atrophy in Age-Related Macular Degeneration: Classification of Atrophy Meeting Report 4.

PURPOSE: To describe the defining features of incomplete retinal pigment epithelium (RPE) and outer retinal atrophy (iRORA), a consensus term referring to the OCT-based anatomic changes often identified before the development of complete RPE and outer retinal atrophy (cRORA) in age-related macular degeneration (AMD). We provide descriptive OCT and histologic examples of disease progression. DESIGN: Consensus meeting. PARTICIPANTS: Panel of retina specialists, including retinal imaging experts, reading center leaders, and retinal histologists. METHODS: As part of the Classification of Atrophy Meeting (CAM) program, an international group of experts analyzed and discussed longitudinal multimodal imaging of eyes with AMD. Consensus was reached on a classification system for OCT-based structural alterations that occurred before the development of atrophy secondary to AMD. New terms of iRORA and cRORA were defined. This report describes in detail the CAM consensus on iRORA. MAIN OUTCOME MEASURES: Defining the term iRORA through OCT imaging and longitudinal cases showing progression of atrophy, with histologic correlates. RESULTS: OCT was used in cases of early and intermediate AMD as the base imaging method to identify cases of iRORA. In the context of drusen, iRORA is defined on OCT as (1) a region of signal hypertransmission into the choroid, (2) a corresponding zone of attenuation or disruption of the RPE, and (3) evidence of overlying photoreceptor degeneration. The term iRORA should not be used when there is an RPE tear. Longitudinal studies confirmed the concept of progression from iRORA to cRORA. CONCLUSIONS: An international consensus classification for OCT-defined anatomic features of iRORA are described and examples of longitudinal progression to cRORA are provided. The ability to identify these OCT changes reproducibly is essential to understand better the natural history of the disease, to identify high-risk signs of progression, and to study early interventions. Longitudinal data are required to quantify the implied risk of vision loss associated with these terms. The CAM classification provides initial definitions to enable these future endeavors, acknowledging that the classification will be refined as new data are generated.

Comparing efficacy of reduced-fluence and standard-fluence photodynamic therapy in the treatment of polypoidal choroidal vasculopathy.

BACKGROUND: The EVEREST II study reported superior polyp closure rates and visual outcomes using combination standard photodynamic therapy (PDT) with intravitreal ranibizumab in the treatment of polypoidal choroidal vasculopathy (PCV). The optimal PDT protocol remains controversial and it is postulated that less intensive PDT strategies may reduce complications. We aimed to compare the efficacy of reduced and standard-fluence PDT. METHODS: Case-control review of 38 consecutive PDT-naïve macular PCV patients who underwent verteporfin PDT using one of two PDT regimens at a tertiary referral centre in an Asian population. Comparison of outcomes between standard-fluence PDT (light dose, 50 J/cm2; dose rate, 600 mW/cm2; wavelength, 689 nm PDT applied to the treatment eye for 83 s) and reduced-fluence PDT (light dose, 25 J/cm2; dose rate, 600 mW/cm2; wavelength, 689 nm PDT applied to the treatment eye for 42 s). Primary outcome measure was best corrected LogMAR visual acuity (VA). Secondary outcome measures included OCT measurements such as central retinal thickness (CRT), height of subfoveal sub-retinal fluid (SRF), central choroid thickness (CCT), mean number of PDT treatments needed, mean number of anti-VEGF injections needed, polyp closure and recurrence rates. RESULTS: Of these 38 eyes of 38 patients, an equal number of eyes (19 in each arm) were treated with standard-fluence and reduced-fluence PDT. Mean letter gain at 12 months for the standard-fluence group was 6.0 compared to 4.3 letters for the reduced-fluence group (p = 0.61). Similar results were observed at all time points. There was no statistically significant difference between the retinal and choroidal anatomical OCT outcomes, rates of polyp closure and recurrences between the two PDT regimens. CONCLUSIONS: Reduced-fluence PDT was comparable to standard-fluence PDT in the treatment of PCV in terms of visual gains, clinical and anatomical OCT outcomes.

Shared genetic variants for polypoidal choroidal vasculopathy and typical neovascular age-related macular degeneration in East Asians.

Polypoidal choroidal vasculopathy (PCV), a subtype of age-related macular degeneration (AMD) more frequently seen in East Asians, has both common and distinct clinical manifestations with typical neovascular AMD (tAMD). We aim to examine the extent to which common genetic variants are shared between these two subtypes. We performed the meta-analysis of association in a total of 1062 PCV patients, 1157 tAMD patients and 5275 controls of East Asian descent from the Genetics of AMD in Asians Consortium at the 34 known AMD loci. A total of eight loci were significantly associated with PCV, including age-related maculopathy susceptibility 2 (ARMS2)-HtrA serine peptidase 1 (HTRA1), complement factor H (CFH), C2-CFB-SKIV2L, CETP, VEGFA, ADAMTS9-AS2 and TGFBR1 (P<5 × 10-4) from the single-nucleotide polymorphism-based test and COL4A3 from the gene-based tests (Pgene=2.02 × 10-4). PCV and tAMD are genetically highly correlated (rg=0.69, P=4.68 × 10-3), with AMD known loci accounting for up to 36% variation. Weaker association for PCV was observed at ARMS2-HTRA1 (Pdif=4.39 × 10-4) and KMT2E-SRPK2(Pdif=4.43 × 10-3), compared with tAMD. Variants at CFH, CETP and VEGFA exhibited different association signals in East Asians, in contrast to those in European individuals. Our data suggest a substantially shared genetic susceptibility for PCV and tAMD, while also highlight the unique associations for PCV, which is useful in understanding the pathogenesis of PCV.

Fundus Photography in the 21st Century--A Review of Recent Technological Advances and Their Implications for Worldwide Healthcare.

BACKGROUND: The introduction of fundus photography has impacted retinal imaging and retinal screening programs significantly. LITERATURE REVIEW: Fundus cameras play a vital role in addressing the cause of preventive blindness. More attention is being turned to developing countries, where infrastructure and access to healthcare are limited. One of the major limitations for tele-ophthalmology is restricted access to the office-based fundus camera. RESULTS: Recent advances in access to telecommunications coupled with introduction of portable cameras and smartphone-based fundus imaging systems have resulted in an exponential surge in available technologies for portable fundus photography. Retinal cameras in the near future would have to cater to these needs by featuring a low-cost, portable design with automated controls and digitalized images with Web-based transfer. CONCLUSIONS: In this review, we aim to highlight the advances of fundus photography for retinal screening as well as discuss the advantages, disadvantages, and implications of the various technologies that are currently available.

IMPROVED SPECIFICITY OF POLYPOIDAL CHOROIDAL VASCULOPATHY DIAGNOSIS USING A MODIFIED EVEREST CRITERIA.

PURPOSE: To evaluate the performance of polypoidal choroidal vasculopathy (PCV) diagnosis using fundus camera-based indocyanine green angiography, comparing a single sign of "subretinal focal hyperfluorescence" on indocyanine green angiography with a modification of the EVEREST criteria. METHODS: Color fundus photograph, flash fundus camera-based fluorescein angiography, and indocyanine green angiography of 241 eyes of 230 consecutive patients with exudative maculopathy due to PCV or typical age-related macular degeneration were graded independently by 2 retinal specialists using a modified EVEREST criteria, which requires the presence of subretinal focal hyperfluorescence plus any 1 of 5 additional criteria. Discordant cases were adjudicated by a senior retinal specialist to arrive at the final diagnosis. Sensitivity, specificity, and area under the receiver operating curve of subretinal focal hyperfluorescence versus the EVEREST criteria and combinations of individual EVEREST criteria were compared. RESULTS: Among the 241 eyes with exudative maculopathy, 131 eyes had PCV and 110 eyes had typical age-related macular degeneration. Using a single sign of subretinal focal hyperfluorescence alone for the diagnosis of PCV, sensitivity was 85.3% and specificity was 80.9%, with an area under the receiver operating curve of 83.1%. When applying the EVEREST definition, sensitivity was reduced to 78.4% but specificity improved to 87.1% with a similar area under the receiver operating curve of 82.8%. The frequency of individual criteria was highly variable, with stereo nodular appearance (73.7%) and orange nodule (55.0%) being the most common and branching vascular network, massive hemorrhage, and hypofluorescent halo in the presence of subretinal focal hyperfluorescence being less common (21.5%-28.1%). CONCLUSION: The EVEREST criteria have a higher specificity for the diagnosis of PCV than subretinal focal hyperfluorescence alone and may be applied to flash fundus camera-based indocyanine green angiography in a clinical setting. Stereo nodular appearance is the most important additional criterion.

Calculating the predicted retinal thickness from spectral domain and time domain optical coherence tomography - comparison of different methods.

PURPOSE: To compare the accuracy of different methods of calculating predicted central retinal thickness values in order to allow comparison between results of spectral-domain optical coherence tomography (SD-OCT) and time-domain OCT (TD-OCT) devices. METHODS: In a prospective cohort study, 100 consecutive healthy individuals without ocular disease underwent sequential scanning with SD-OCT (Spectralis OCT) and TD-OCT (Stratus OCT). A group of 60 eyes was used to generate the conversion equations, which were tested on the remaining 140 eyes. Four equations were used: 1. Mean difference between SD-OCT and TD-OCT; 2. Multiplying a ratio by the original retinal thickness; 3. Linear regression analysis using retinal thickness; and 4. Regression analysis using retinal thickness and spherical equivalent. All four methods were used to calculate predicted SD-OCT values from TD-OCT measurements, and vice versa. RESULTS: For all four equations, the predicted SD-OCT central retinal thickness values were similar to the actual SD-OCT, with mean difference ranging from 0.78 to 1.01 µm, and intraclass correlation coefficients >0.88. Both regression equations and mean difference showed greater accuracy, with variation between calculated and actual retinal thickness values ≤5 µm in 60% of eyes. In contrast, the ratio method was less accurate, with 15.8 % of eyes showing differences >15 µm. Similar results were found for predicted TD-OCT values. CONCLUSIONS: Several methods can be used to convert central retinal thickness values from SD-OCT to the predicted TD-OCT value, or vice versa, with high degrees of accuracy and reliability. These methods may allow comparison of OCT values from SD-OCT and TD-OCT devices in clinical trials and standard patient care.

Generalizability of Deep Neural Networks for Vertical Cup-to-Disc Ratio Estimation in Ultra-Widefield and Smartphone-Based Fundus Images.

Purpose: To develop and validate a deep learning system (DLS) for estimation of vertical cup-to-disc ratio (vCDR) in ultra-widefield (UWF) and smartphone-based fundus images. Methods: A DLS consisting of two sequential convolutional neural networks (CNNs) to delineate optic disc (OD) and optic cup (OC) boundaries was developed using 800 standard fundus images from the public REFUGE data set. The CNNs were tested on 400 test images from the REFUGE data set and 296 UWF and 300 smartphone-based images from a teleophthalmology clinic. vCDRs derived from the delineated OD/OC boundaries were compared with optometrists' annotations using mean absolute error (MAE). Subgroup analysis was conducted to study the impact of peripapillary atrophy (PPA), and correlation study was performed to investigate potential correlations between sectoral CDR (sCDR) and retinal nerve fiber layer (RNFL) thickness. Results: The system achieved MAEs of 0.040 (95% CI, 0.037-0.043) in the REFUGE test images, 0.068 (95% CI, 0.061-0.075) in the UWF images, and 0.084 (95% CI, 0.075-0.092) in the smartphone-based images. There was no statistical significance in differences between PPA and non-PPA images. Weak correlation (r = -0.4046, P < 0.05) between sCDR and RNFL thickness was found only in the superior sector. Conclusions: We developed a deep learning system that estimates vCDR from standard, UWF, and smartphone-based images. We also described anatomic peripapillary adversarial lesion and its potential impact on OD/OC delineation. Translational Relevance: Artificial intelligence can estimate vCDR from different types of fundus images and may be used as a general and interpretable screening tool to improve community reach for diagnosis and management of glaucoma.

Asian age-related macular degeneration phenotyping study: rationale, design and protocol of a prospective cohort study.

BACKGROUND: Current knowledge of the phenotypic characteristics (e.g. clinical features, risk factors, natural history and treatment response) of age-related macular degeneration (AMD) in Asians remains limited. This report summarizes the rationale and study design of a prospective observational study of Asian neovascular AMD, including polypoidal choroidovasculopathy variant. DESIGN: The Asian AMD phenotyping study is a prospective, observational clinical study of Asian patients with neovascular AMD or polypoidal choroidovasculopathy in three tertiary eye centres in Singapore. PARTICIPANTS: The study aims to recruit 500 consecutive patients from the retinal clinics of three tertiary eye centres in Singapore. METHODS: Standardized examination procedures include interviews, a comprehensive eye examination, digital photography of the retina, fundus fluorescein and indocyanine green angiography and spectral domain optical coherence tomography using a standardized protocol. Blood samples were collected for biochemical analyses and stored for genetic and proteomic studies. MAIN OUTCOME MEASURES: The aim of the study was to build a comprehensive database of clinical, angiographic, functional and natural history data of Asian AMD over a 12-month follow-up period. RESULTS: This article discusses the methodology and design of this prospective multi-centred study. CONCLUSION: This study will provide in-depth longitudinal data of the evolution of clinical features, risk factors, natural history and treatment pattern and response of Asian AMD and polypoidal choroidovasculopathy, allowing unique insights into pathogenesis and the design of new treatment strategies.

Brief Report: Retinal Microvasculature and Immune Restoration Among South Eastern Asian Patients With HIV/AIDS Over a 9-Month Antiretroviral Therapy.

BACKGROUND: Longitudinal evidence on retinal microvasculature and subsequent systemic inflammatory alteration is lacking. We investigated the association between retinal microvasculature and immune response among patients with HIV/AIDS over a 9-month antiretroviral therapy. METHODS: We conducted a prospective cohort study on patients with HIV/AIDS at Singapore Communicable Disease Centre since June 2011. We recruited all eligible patients and then reviewed them every 3 months over a 9-month follow-up, including performing blood tests (CD4+/CD8+ T-cell counts and HIV viral load), blood pressure, anthropometry measurements, and retinal photography at each visit. We assessed retinal vascular indexes using a semiautomated computer-based program. Finally, we applied a linear mixed model to analyze associations between baseline retinal vascular indexes and 9-month changes of CD4+/CD8+ T-cell counts and HIV viral load throughout study observation, after adjusting for major confounders. RESULTS: We found that narrower arteriolar caliber (per 10 µm decrease), wider venular caliber (per 10 µm increase), and larger arteriolar branching angle (per 10° increase) in the retina assessed at baseline were significantly associated with 9-month reductions in CD4+ T-cell count by 52.97 cells/µL (P = 0.006), 33.55 cells/µL (P = 0.01), and 39.09 cells/µL (P = 0.008), accordingly. CONCLUSION: Patients with HIV/AIDS with a suboptimal retinal microvascular morphology tended to fail immune restoration undertaking a 9-month antiretroviral therapy.

Acute Atypical Endophthalmitis Following Intravitreal Sustained-release Dexamethasone Implant: A Case Series.

PURPOSE: To present three cases of acute endophthalmitis following intravitreal sustained-release dexamethasone (Ozurdex®) with atypical presentation and to discuss the management of these patients. METHODS: A retrospective case series of three patients with endophthalmitis following intravitreal sustained-release dexamethasone (Ozurdex®) implantation who presented between July 2020 to August 2020. RESULTS: Two out of three patients who were treated with topical steroid and antibiotic therapy alone showed favorable outcomes and were managed without the need for intravitreal antibiotics or implant removal. One patient who showed initial response to topical therapy subsequently required pars plana vitrectomy, implant removal and a single empirical dose of intra-vitreal antibiotics and anti-fungal agent due to persistent inflammation. CONCLUSION: Post intravitreal Ozurdex® endophthalmitis although a rare entity can present with atypical features of a painless white eye and a delayed onset intraocular inflammation. Although all cases of endophthalmitis should be treated as infective until proven otherwise, it is fair to consider a trial of conservative treatment with topical steroids and antibiotics initially with close monitoring. In cases with poor response to topical therapy, pars planar vitrectomy and implant removal should be strongly considered.

Diagnosing Persistent Hypertransmission Defects on En Face OCT Imaging of Age-Related Macular Degeneration.

PURPOSE: A training exercise was performed to study the ability of graders to reliably identify precursor lesions to geographic atrophy (GA), known as persistent choroidal hypertransmission defects (hyperTDs), using en face OCT images from eyes with nonexudative age-related macular degeneration (AMD). DESIGN: Intergrader agreement study. PARTICIPANTS: Eleven graders participated in this exercise. METHODS: Formal training on how to identify persistent hyperTDs on en face OCT images was provided to the graders. A persistent hyperTD was defined as a bright lesion having a greatest linear dimension (GLD) of at least 250 µm. Training consisted of a tutorial session followed by the grading of 3 pretest exercises, each consisting of 3 cases. After all graders scored 100% on the pretest exercises, they performed a final exercise consisting of 30 en face OCT images from 29 eyes with nonexudative AMD containing 107 hyperTDs that each grader needed to evaluate. The cases contained a variety of AMD-related atrophic lesions. MAIN OUTCOME MEASURES: The sensitivity, positive predictive value (PPV), and modified accuracy were assessed for each grader. RESULTS: A total of 1177 hyperTDs from 30 en face OCT images were reviewed by the graders. The mean sensitivity, PPV, and modified accuracy for all the graders were calculated to be 99.0%, 99.2%, and 98.2%, respectively. There was a 97% agreement observed between all the graders (first-order agreement coefficient [AC1] = 0.97). Internal graders from the Bascom Palmer Eye Institute had a slightly higher agreement compared with the external graders (AC1 = 0.98 vs. AC1 = 0.96). The hyperTDs most often incorrectly identified included the following features: (1) hyperTDs containing hypotransmission defect cores, (2) single hyperTDs that were incorrectly graded as 2 separate lesions, and (3) hyperTDs with borderline GLDs that were close to 250 µm. CONCLUSIONS: The accurate detection of persistent hyperTDs on en face OCT images by graders demonstrates the feasibility of using this OCT biomarker to identify disease progression in eyes with nonexudative AMD, especially when used as a clinical trial end point in studies designed to test new therapies that may slow disease progression from intermediate AMD to GA.

Verteporfin PDT for non-standard indications--a review of current literature.

BACKGROUND: Verteporfin photodynamic therapy (PDT) is approved for the treatment of predominantly classic subfoveal choroidal neovascularization (CNV) due to age-related macular degeneration (AMD), as well as for subfoveal CNV due to pathologic myopia and ocular histoplasmosis syndrome. Verteporfin PDT addresses the underlying pathology of ocular vascular disorders through its angio-occlusive mechanism of action, which reduces both visual acuity loss and the underlying leakage associated with lesions. Verteporfin PDT has also been associated with encouraging treatment outcomes in case studies involving patients with choroidal vascular disorders such as polypoidal choroidal vasculopathy, central serous chorioretinopathy, choroidal haemangioma, angioid streaks, and inflammatory CNV, i.e. conditions currently considered as non-standard indications of verteporfin PDT. In many studies, outcomes were better than expected based on the natural courses of each of these conditions. Although the anti-vascular endothelial growth factor (VEGF) therapies, ranibizumab and pegaptanib, have been approved for CNV due to AMD, their role in these other choroidal vascular disorders remains to be established. We summarize current literature that has documented the use of verteporfin PDT in these conditions. CONCLUSIONS: The complex pathogenesis of CNV provides a rationale for investigating combination approaches comprising verteporfin PDT and anti-VEGF therapies. Randomized controlled studies are warranted to confirm the preliminary results of verteporfin PDT as a monotherapy or in combination with anti-VEGF therapies in the treatment of a variety of choroidal vascular conditions.

Automatic Detection of Preferred Retinal Locus (PRL) for Low Vision Rehabilitation using Oculometrics Analysis.

Low vision rehabilitation is an important step towards individuals with Age-related macular degeneration (AMD) regaining useful functional vision and quality of life. One of the key steps in low vision rehabilitation is the determination of the preferred retinal locus (PRL). Currently, localization of PRL is performed manually though the guidance of a low vision therapist and the process is highly time-consuming, labour-intensive and subjective. In this paper, we present an automated system to objectively and accurately locate an individual's PRL with the aid of gaze tracking technology. We also propose a graph-based method for false fixation detection to improve the system robustness. We validated the reliability of the system by using eye tracking technology to simulate central vision loss on people with normal vision. Experimental results show the potential use of eye tracking in detecting PRL for low vision rehabilitation.

EVEREST Report 5: Clinical Outcomes and Treatment Response of Polypoidal Choroidal Vasculopathy Subtypes in a Multicenter, Randomized Controlled Trial.

Purpose: The purpose of this study was to describe the characteristics of polypoidal choroidal vasculopathy (PCV) subtypes among patients from a multicenter randomized controlled trial and to determine the impact of PCV subtypes on clinical outcomes. Methods: This was a prospective cohort study of 61 patients with macular PCV from the EVEREST study. Indocyanine green (ICGA) and fluorescein angiography (FA) obtained using standardized imaging protocols were graded to classify PCV into three subtypes. Type A PCV had polyps with interconnecting channels, type B had polyps with branching vascular networks, but no significant leakage on FA, and type C had polyps with branching vascular networks and leakage on FA. The best-corrected visual acuity (BCVA) and proportion of patients with BCVA ≥ 20/40 were compared among the three PCV subtypes. Results: Of the 61 patients, 54 were gradable for PCV subtype. Among these, 8 had type A PCV (14.8%), 27 had type B (50%), and 19 had type C (35.2%). At baseline, BCVA was 67.1 letters for type A, 58.7 for type B, and 43.5 for type C (P < 0.001). At 6 months, BCVA was highest among patients with type A compared with types B and C (80.1 letters versus 67.2 versus 50.4, respectively; P < 0.001). Type A PCV gained 13 letters compared with 8.5 (type B) and 6.9 (type C). BCVA ≥ 20/40 was highest for type A compared with types B and C (100% vs. 51.9% vs. 10.5%; P < 0.001). On performing ANCOVA, PCV subtype and baseline BCVA significantly affected final BCVA. Conclusions: The visual outcome following treatment varies with PCV subtype classification. The distinction in clinical outcomes between the PCV subtypes is observed in the initial months following the start of treatment.

Human pharyngeal microbiota in age-related macular degeneration.

BACKGROUND: While the aetiology of age-related macular degeneration (AMD)-a major blinding disease-remains unknown, the disease is strongly associated with variants in the complement factor H (CFH) gene. CFH variants also confer susceptibility to invasive infection with several bacterial colonizers of the nasopharyngeal mucosa. This shared susceptibility locus implicates complement deregulation as a common disease mechanism, and suggests the possibility that microbial interactions with host complement may trigger AMD. In this study, we address this possibility by testing the hypothesis that AMD is associated with specific microbial colonization of the human nasopharynx. RESULTS: High-throughput Illumina sequencing of the V3-V6 region of the microbial 16S ribosomal RNA gene was used to comprehensively and accurately describe the human pharyngeal microbiome, at genus level, in 245 AMD patients and 386 controls. Based on mean and differential microbial abundance analyses, we determined an overview of the pharyngeal microbiota, as well as candidate genera (Prevotella and Gemella) suggesting an association towards AMD health and disease conditions. CONCLUSIONS: Utilizing an extensive study population from Singapore, our results provided an accurate description of the pharyngeal microbiota profiles in AMD health and disease conditions. Through identification of candidate genera that are different between conditions, we provide preliminary evidence for the existence of microbial triggers for AMD. Ethical approval for this study was obtained through the Singapore Health Clinical Institutional Review Board, reference numbers R799/63/2010 and 2010/585/A.

Systemic, Ocular and Genetic Risk Factors for Age-related Macular Degeneration and Polypoidal Choroidal Vasculopathy in Singaporeans.

To examine the association of systemic, ocular and genetic risk factors in neovascular age-related macular degeneration (nAMD) in a large cohort of Asian patients, and to further compare risk factors between those with typical AMD and polypoidal choroidal vasculoapthy (PCV) subtypes. We recruited 456 cases and 1,824 controls matched for age, gender and ethnicity. Data on systemic and ocular risk factors were collected on questionnaires. In a subgroup of subjects, we included genetic data on four AMD-associated single nucleotide polymorphisms (SNPs). Risk factors for nAMD and subtypes were analyzed. Systemic risk factors for nAMD included older age, male gender, higher BMI and higher HDL-cholesterol. Ocular risk factors included pseudophakic and shorter axial length. Risk factors common to both typical AMD and PCV subtypes included age, BMI and HDL-cholesterol. Shorter axial length was only associated with PCV, while male gender and pseudophakia were only associated with typical AMD. In the subgroup with genotype data, ARMS2 rs10490924 and CFH rs800292 were associated with nAMD. None of the risk factors were significantly different between PCV and typical AMD. Systemic, ocular and genetic risk factors were largely similar for typical AMD and PCV subtypes in this Asian population based in Singapore.

HDL-cholesterol levels and risk of age-related macular degeneration: a multiethnic genetic study using Mendelian randomization.

Background: Dyslipidemia, particularly high-density lipoprotein cholesterol (HDL-C), has recently been implicated in the pathogenesis of age-related macular degeneration (AMD), the leading cause of vision loss. However, epidemiological studies have yielded conflicting results. Methods: We investigated the causal role of plasma lipid levels in AMD in multiethnic populations comprising 16 144 advanced AMD cases and 17 832 controls of European descent, together with 2219 cases and 5275 controls of Asian descent, using Mendelian randomization in three models. Model 1 is a conventional meta-analysis which does not account for pleiotropy of instrumental variable (IV) effects. Model 2 is a univariate, inverse variance weighted regression analysis that accounts for potential unbalanced pleiotropy using MR-Egger method. Finally, Model 3 is a multivariate regression analysis that addresses pleiotropy by MR-Egger method and by adjusting for effects on other lipid traits. Results: A 1 standard deviation (SD) higher HDL-cholesterol level was associated with an odds ratio (OR) for AMD of 1.17 (95% confidence interval: 1.07-1.29) in Europeans (P = 6.88 × 10-4) and of 1.58 (1.24-2.00) in Asians (P = 2.92 × 10-4) in Model 3. The corresponding OR estimates were 1.30 (1.09-1.55) in Europeans (P = 3.18 × 10-3) and 1.42 (1.11-1.80) in Asians (P = 4.42 × 10-3) in Model 1, and 1.21 (1.11-1.31) in Europeans (P = 3.12 × 10-5) and 1.51 (1.20-1.91) in Asians (P = 7.61 × 10-4) in Model 2. Conversely, neither LDL-C (Europeans: OR = 0.96, P = 0.272; Asians: OR = 1.02, P = 0.874; Model 3) nor triglyceride levels (Europeans: OR = 0.91, P = 0.102; Asians: OR = 1.06, P = 0.613) were associated with AMD. We also assessed the association between lipid levels and polypoidal choroidal vasculopathy (PCV) in Asians, a subtype of AMD, and found a similar trend for association of PCV with HDL-C levels. Conclusions: Our study shows that high levels of plasma HDL-C are causally associated with an increased risk for advanced AMD in European and Asian populations, implying that strategies reducing HDL-C levels may be useful to prevent and treat AMD.

Drug, delivery and devices for diabetic retinopathy (3Ds in DR).

INTRODUCTION: Diabetic Retinopathy (DR) is one of the most common causes of blindness among the working population worldwide. Clearly, there is an unmet clinical need to find better treatment options for DR. Areas covered: The literature search was conducted on PubMed with no limitation on language or year of publication. The review focuses on the clinically used drugs/proteins along with a brief background on the pathophysiology of DR. The major focus of this review revolves around three treatment approaches involving drugs/proteins, drug delivery formulations and drug delivery devices. In each category, major advances are discussed along with the possible solutions. We have also discussed the various modes of administration that are currently being evaluated in the clinic. An attempt has been made to address the potential targeted site of action for DR drug delivery, and also to understand the role of Blood Retinal Barrier (BRB). Expert Opinion: In the current scenario, although there have been some advances in the drug delivery devices for delivering drugs/proteins, there are still challenges to be overcome with regard to the particulate systems. For long-term success of DR therapeutics, research options should consider taking into account the 3Ds (drug, delivery and devices).