The epidemiology of age-related macular degeneration in the Indian subcontinent

Brolucizumab in age-related macular neovascularization (BRAIN study): Efficacy, optical coherence tomography biomarkers, and safety profile

BACKGROUND

Brolucizumab is a new anti-vascular endothelial growth factor (anti-VEGF) in the treatment of neovascular age-related macular degeneration (nAMD) and idiopathic polypoidal choroidal vasculopathy (IPCV).

MATERIALS AND METHODS

A retrospective, consecutive, interventional study was conducted from a tertiary eye hospital, in which treatment-naïve and treatment-switch patients were included. They underwent an intravitreal injection of brolucizumab. The decision to reinject was made based on the presence of fluid on spectral domain optical coherence tomography (SD-OCT) or worsening of vision at follow-up. Outcome measures were changes in best-corrected visual acuity (BCVA), central subfield thickness (CST), fluid (subretinal/intraretinal/sub-retinal pigment epithelium fluid) levels, and OCT biomarkers and safety analysis.

RESULTS

A total of 59 eyes of 50 patients with a total of 132 intravitreal injections were included. There was a statistically significant improvement (P < 0.05) in BCVA from baseline in logMAR treatment-naïve patients (mean BCVA at baseline 0.6 ± 0.41 and 0.37 ± 0.56). The mean baseline CST of all patients significantly reduced from 582.92 ± 233.11 µm at baseline to 474.06 ± 252.89 µm at the final treatment visit. Thirty-eight percent of patients showed complete resolution of SHRM after a single injection. The interval between each subsequent injection increased from a mean of 67 to 96 days in treatment-switch patients and from 47 to 151 days in treatment-naïve patients.

CONCLUSION

Brolucizumab promises reduced number of injections with longer treatment intervals.

Diagnostic accuracy of handheld fundus photography: A comparative study of three commercially available cameras

The objective of this study was to compare the sensitivity and specificity of handheld fundus cameras in detecting diabetic retinopathy (DR), diabetic macular edema (DME), and macular degeneration. Participants in the study, conducted at Maharaj Nakorn Hospital in Northern Thailand between September 2018 and May 2019, underwent an ophthalmologist examination as well as mydriatic fundus photography with three handheld fundus cameras (iNview, Peek Retina, Pictor Plus). Photographs were graded and adjudicated by masked ophthalmologists. Outcome measures included the sensitivity and specificity of each fundus camera for detecting DR, DME, and macular degeneration, relative to ophthalmologist examination. Fundus photographs of 355 eyes from 185 participants were captured with each of the three retinal cameras. Of the 355 eyes, 102 had DR, 71 had DME, and 89 had macular degeneration on ophthalmologist examination. The Pictor Plus was the most sensitive camera for each of the diseases (73-77%) and also achieved relatively high specificity (77-91%). The Peek Retina was the most specific (96-99%), although in part due to its low sensitivity (6-18%). The iNview had slightly lower estimates of sensitivity (55-72%) and specificity (86-90%) compared to the Pictor Plus. These findings demonstrated that the handheld cameras achieved high specificity but variable sensitivities in detecting DR, DME, and macular degeneration. The Pictor Plus, iNview, and Peek Retina would have distinct advantages and disadvantages when applied for utilization in tele-ophthalmology retinal screening programs.

Geographic distributions of age-related macular degeneration incidence: a systematic review and meta-analysis

PURPOSE

We performed a systematic review and meta-analysis to summarise the geographic distribution of age-related macular degeneration (AMD) incidence.

METHODS

Databases including PubMed, Embase and Web of Science were searched for publications of early and late AMD before September 2019. Studies were included if they applied a standardised photographic assessment and classification system. The proportion of participants with AMD in each eligible study was combined to obtain a pooled incidence from all studies using a random effects model. We also assessed sources of potential heterogeneity in the incidence of AMD using meta-regression analyses for both late and early AMD.

RESULTS

Twenty-four population-based studies (70 123 individuals aged 55 years or older) were included in the meta-analysis. The pooled global annual incidences of early and late AMD were 1.59% (95% CI 1.12% to 2.10%) and 0.19% (95% CI: 0.13% to 0.28%), respectively. Individuals of European descent had the highest annual incidence of both early (2.73%, 95% CI 1.63% to 4.57%) and late (0.36%, 95% CI 0.17% to 0.75%) AMD than other ethnic groups. Average age (p=0.001) at baseline, ethnicity (p=0.001), region (p=0.043) and gender (p=0.011) were predictors for incident late AMD, while only average age (p=0.01) at baseline and ethnicity (p=0.025) was associated with incidence of early AMD.

CONCLUSIONS

This meta-analysis offers an up-to-date overview of AMD globally, which may provide scientific guidance for the design and implementation of public health strategies such as screening programmes for AMD in both specific geographic locations and ethnic groups, as well as worldwide.

A Multicenter, Retrospective Study (RE-ENACT 2) on the Use of Razumab™ (World's First Biosimilar Ranibizumab) in Wet Age-Related Macular Degeneration

INTRODUCTION

The REal life assessmENt of safety And effeCTiveness of Razumab (RE-ENACT) and long-term RE-ENACT 2 retrospective studies have evaluated the use of Razumab™ (world's first biosimilar ranibizumab) in retinal disorders in Indian patients. This report presents the subgroup analysis from the RE-ENACT 2 study in patients with wet age-related macular degeneration (wet AMD).

METHODS

Medical charts of patients administered biosimilar ranibizumab injections as PRN treatment regimen between September 2015 and June 2018, at 17 centers across India, were reviewed. Changes from baseline in best-corrected visual acuity (BCVA, based on Snellen's or logMAR chart), central subfield thickness (CSFT), intraocular pressure (IOP), and proportions of patients having intraretinal fluid (IRF) and subretinal fluid (SRF) at weeks 4, 8, 12, 16, 20, 24, 30, 36, and 48 were evaluated.

RESULTS

Of 103 patients with wet AMD, 62.1% were men and the majority (74.8%) were treatment naïve. The majority (57.9%) of the patients had received 3 (range 1-5) injections. Significant improvements were observed from baseline to all timepoints for BCVA (baseline, 0.92 ± 0.6 [n = 94]; week 48, 0.51 ± 0.4 [n = 14]; P = 0.0014) and CSFT (baseline, 430.83 ± 14.4 [n = 85]; week 48, 301.26 ± 11.6 [n = 15]; P < 0.0001). Changes in IOP from baseline to 48 weeks were minimal and not significant (14.92 ± 3.2 [n = 94] vs. 14.50 ± 2.1 [n = 18]; P = 0.9068). A decrease in proportions of patients having IRF (baseline, 63.6% [n = 99] vs. week 48, 15% [n = 20]) and SRF (baseline, 82.3% [n = 96] vs. week 48, 5% [n = 20]) were also observed. Similar results were observed for occult and classic subgroups. There were no new safety concerns.

CONCLUSION

Razumab (biosimilar ranibizumab) demonstrated improvements in visual acuity and disease outcomes in patients with wet age-related macular degeneration without new safety issues.

Pachydrusen in Indian population: A hospital-based study

Purpose:

To report the prevalence of pachydrusen in Indian population and their characteristics in relation to subfoveal choroidal thickness (SFCT), choroidal vascularity index (CVI) in comparison to eyes with soft drusen and subretinal drusenoid deposits (SDD) in age-related macular degeneration (AMD).

Methods:

The study was a retrospective, cross-sectional study involving patients with a diagnosis of dry AMD in at least one eye. The diagnosis of soft drusen, SDD, and pachydrusen was made on the basis of color fundus photograph and optical coherence tomography (OCT). SFCT and CVI was calculated and compared among the different subtypes of drusen.

Results:

A total of 169 eyes (143 dry and 26 wet AMD) of 85 patients with a mean age of 67.67 ± 9.57 years were included. In eyes with dry AMD, pachydrusen were seen in 12 eyes (8.4%) with a mean (±SD) SFCT of 289.66 ± 91.01 μ. The difference in SFCT was statistically significant (P = 0.001) using analysis of variance (ANOVA) test. The eyes with pachydrusen had significantly thickened choroid compared to the eyes with SDD (30 eyes; 21.0%) or combination of soft drusen and SDD (29 eyes; 20.3%) but not soft drusen (72 eyes; 50.3%). The difference of CVI in different subgroups was significant (P = 0.03). One eye in wet AMD group had concurrent pachydrusen. Comparison of SFCT and CVI in wet AMD and fellow dry AMD eyes were not significant.

Conclusion:

In Indian eyes with dry AMD, prevalence of pachydrusen (8.4%) is slightly lower compared to western literature (11.7%) and is associated with thicker choroid and higher CVI.

Prevalence and causes of low vision and blindness in an elderly population in Nepal: the Bhaktapur retina study

BACKGROUND

This study aims to explore the prevalence and causes of low vision and blindness focused on retinal disease in a population above 60 years in Nepal.

METHODS

Two thousand one hundred subjects were enrolled in a population-based cross-sectional study. History, presenting and best corrected visual acuity after subjective refraction, anterior and posterior segment examinations was obtained in detail.

RESULTS

Among the total subjects, 1860 (88.57%) had complete information. Age varies from 60 to 95 (mean age: 69.64 ± 7.31) years. Low vision and blindness in both eyes at presentation was found in 984 (52.90%, 95% confidence interval (CI): 50.60-55.19) and 36 (1.94%, 95% CI: 1.35-2.66) subjects respectively. After best correction, bilateral low vision and blindness was found in 426 (22.92%, 95% CI: 21.01-24.88), and 30 (1.61%, 95% CI: 0.10-2.30) subjects respectively. As compared to 60-69 years old, risk of visual impairment was four times higher (95% CI:3.26-5.58) in the 70-79 year olds and 14 times higher (95% CI: 9.72-19.73) in the age group 80 years and above. Major causes of bilateral low vision were cataract (68.07%), followed by retinal disorders (28.64%), and for blindness; retinal disorders (46.66%), followed by cataract (43.33%). Illiteracy was significantly associated with visual impairment.

CONCLUSION

Among the elderly population, prevalence of visual impairment was high. Refractive error, cataract and retinal disorders were the major cause of low vision. Screening the population at the age 60 years and above, focused on cataract and posterior segment diseases, providing glasses and timely referral can help reduce visual impairment.

Six-Year Incidence and Progression of Age-Related Macular Degeneration in Kenya: Nakuru Eye Disease Cohort Study

Question

What is the incidence of age-related macular degeneration in Kenya?

Findings

A 6-year, population-based cohort study of 4414 adult Kenyans (≥50 years of age) was conducted, and the 6-year weighted cumulative incidence of early age-related macular degeneration was 164.2 per 1000 persons.

Meaning

These results suggest that age-related macular degeneration may become a greater public health concern in Kenya and similar countries in the future with population aging in these regions.

Importance

The incidence of age-related macular degeneration (AMD) is unknown in Africa.

Objective

To estimate the 6-year cumulative incidence and progression of AMD in older adults (≥50 years old) in Nakuru, Kenya.

Design, Setting, and Participants

This study assessed a population-based cohort with 6-year follow-up of 4414 participants who had a complete assessment. Random cluster sampling with probability proportionate to size procedures was used to select a representative, cross-sectional sample of adults 50 years and older from January 26, 2007, through November 11, 2008. A 6-year follow-up was undertaken from January 7, 2013, through March 12, 2014. On both occasions, a comprehensive ophthalmic examination was performed that included logMAR visual acuity, digital retinal photography, and grading of images at Moorfields Eye Hospital Reading Centre. Data were collected on general health and risk factors.

Main Outcomes and Measures

Incident AMD in participants with no AMD at baseline and progression from early to late AMD.

Results

A total of 1453 of the 2900 individuals (50.1%) at risk for AMD were followed up after 6 years (mean [SD] age, 60.7 [8.2] years; 635 female [49.5%]; 799 Kikuyu [62.3%], 324 Kalenjin [25.3%], and 159 other [12.4%]); 1282 had data on AMD status at follow-up. Of these, 202 developed early AMD, and no participants developed late AMD. The 6-year weighted (for loss to follow-up) cumulative incidence of early AMD was 164.2 per 1000 persons (95% CI, 136.7-195.9 per 1000 persons). Two individuals with baseline early AMD from the 142 at risk had developed late AMD at follow-up, with a 6-year cumulative incidence of progression from early to late AMD of 24.5 per 1000 persons (95% CI, 5.0-111.7 per 1000 persons). Cumulative incidence of AMD increased with age (≥80 years old vs 50-59 years old: 1.8; 95% CI, 0.9-3.5) and was higher in women (female vs male: 1.6; 95% CI, 1.2-2.1) and persons with diabetes (diabetes vs no diabetes: 1.7; 95% CI, 1.0-2.8).

Conclusions and Relevance

In Kenya, more than 100 000 estimated new cases of AMD, mainly early AMD, will develop every year in individuals 50 years or older, although a 50% loss to follow-up and wide CIs for progression to late AMD limit definitive conclusions from these findings.

Prevalence and the risk factors for visual impairment in age-related macular degeneration

PurposeTo characterize the type, and the causes of visual impairment (VI) in various stages of early and late age-related macular degeneration (AMD) and the factors associated with visual impairment in subjects with AMDMethods6617 subjects ≥60 years were enumerated; 5495 (83.04%) participated in eye examination. Of which, 4791 subjects had gradable fundus images. AMD was graded per International ARM Epidemiological Study Group. Subjects underwent detailed ophthalmic exam. VI was defined per the WHO classification. Mild VI was defined as VA less than 6/12 to 6/18, moderate VI-VA less than 6/18 but up to 6/60, severe VI-VA less than 6/60 but up to 3/60 and legal blindness-VA worse than 3/60. Factors associated with VI in AMD was analyzed with univariate and logistic regression analysis.ResultsNine hundred and eighty-eight subjects were identified as having AMD (893 with early AMD and 95 with late AMD); 85% of the subjects (95% CI: 82.7-87.1) had no VI, 13.1% had mild VI (95% CI: 11.1-15.3), 0.8% had severe VI (95% CI: 0.4-1.6), 1.1% had legal blindness (95% CI: 0.6-1.9). Prevalence of any VI was 13.7% in early AMD and 27.4% in late AMD, P=0.0004; age group 65-70 years (OR=1.89, 95% CI: 1.16-3.08, P=0.011), and those ≥75 years (OR=3.67, 95% CI: 1.95-6.91, P=0.0001) had greater odds of VI compared with age group 60-64 years. Male gender was a protective factor for VI (OR=0.57, CI: 0.36-0.90, P=0.016). Cataract (31.8%) and refractive error (28.4%) accounted for a majority of the VI.ConclusionsCataract and refractive error account for a significant proportion of VI in the south Indian population with AMD. Early AMD is the third leading cause of VI. Greater age and female gender are associated with VI in subjects with AMD.

Prevalence of and risk factors for age-related macular degeneration in Nepal: the Bhaktapur Retina Study

Aim

This study aimed to explore the prevalence of and risk factors for age-related macular degeneration (AMD) in an elderly population in Nepal.

Subjects and methods

This is a population-based, cross-sectional study. A sample size of 2,100 was calculated. A total of 1,860 (88.6%) subjects aged >60 years were enrolled for the study from 30 clusters in the district. Detailed history, visual acuity, and anterior segment and posterior segment examinations were performed. AMD was graded according to the International ARM Epidemiological Study Group.

Results

Among the total study population, 659 subjects had any AMD (35.43%; 95% confidence interval [CI]: 33.25–37.65), 484 had mild dry AMD (26.02%; 95% CI: 24.04–28.08), 143 had intermediate dry AMD (7.69%; 95% CI: 6.52–8.99), 19 had geographic atrophy (1.02%; 95% CI: 0.61–1.59), and 13 had wet AMD (0.70%; 95% CI: 0.37–1.19). The overall prevalence of early and late AMD was 33.71% and 1.72%, respectively. Among subjects with dry and wet AMD, 36.53% and 46.1% had visual impairment, while 2.78% and 23.08% were blind, respectively. In multivariate analysis, AMD was significantly higher in subjects with an increased number of cigarettes smoked per day (odds ratio [OR] 1.02, 95% CI: 1.01–1.04; P=0.007) and in subjects with pseudophakia (OR 1.45, 95% CI: 1.12–1.87; P=0.005).

Conclusion

One-third of the population aged ≥60 years have some form of AMD. There was a significant association with the number of cigarettes consumed and with previous cataract surgery.

MiR-126 overexpression inhibits high glucose-induced migration and tube formation of rhesus macaque choroid-retinal endothelial cells by obstructing VEGFA and PIK3R2

AIM

The aims of this study are to investigate the relative regulation between miR-126 and VEGF/PI3K/AKT signaling pathway in retinal vascular endothelial cells.

METHODS

Rhesus macaque choroid-retinal endothelial cell line (RF/6A) cells were cultured in high glucose to imitate the conditions occurring in DR. First, we detected the expression of miR-126, VEGFA and PIK3R2 in RF/6A cells on the condition of high glucose by q-PCR and western blot. Then, after addition of miR-126 mimics and miR-126 inhibitor, we investigated the function of miR-126 in RF/6A cells by scratch wound, Transwell migration and tube formation assays, and the effect of miR-126 on the expression of VEGFA, PIK3R2 and AKT. Moreover, bioinformatics analysis and luciferase array were used to confirm the direct or specific regulation of miR-126 to VEGFA or PIK3R2.

RESULTS

Here, first, we found that high glucose could induce the decrease of miR-126 and the increase of VEGFA and PIK3R2 in RF/6A. Then, by scratch wound, Transwell migration and tube formation assays, we found that miR-126 overexpression could inhibit the migration and sprouting of RF/6A cells induced by high glucose, while knockdown of miR-126 led to the opposite results. Moreover, overexpression of miR-126 inhibited the increased expression of VEGFA, PIK3R2, SDF-1α, VCAM-1, and SPRED1, and the activation of AKT1 induced by high glucose and miR-126 inhibitor caused the opposite results which were determined by q-PCR and western blot. In addition, by luciferase assay, we found that miR-126 could directly negatively regulate VEGFA and PIK3R2.

CONCLUSION

Our results suggest that miR-126 overexpression inhibits the migration and sprouting of RF/6A cells induced by high glucose which might possibly be by blocking VEGFA and PIK3R2 in the VEGF/PI3K/AKT signaling pathway.

Intra- and inter-rater agreement between an ophthalmologist and mid-level ophthalmic personnel to diagnose retinal diseases based on fundus photographs at a primary eye center in Nepal: the Bhaktapur Retina Study

BACKGROUND

Early detection can reduce irreversible blindness from retinal diseases. This study aims to assess the intra- and inter-rater agreement of retinal pathologies observed on fundus photographs between an ophthalmologist and two-mid level ophthalmic personnel (MLOPs).

METHOD

A population-based, cross-sectional study was conducted among subjects 60 years and above in the Bhaktapur district of Nepal. Fundus photographs of 500 eyes of 500 subjects were assessed. The macula-centered 45-degree photographs were graded twice by one ophthalmologist and two MLOPs. Intra-rater and inter-rater agreements were assessed for the ophthalmologist and the MLOPs.

RESULT

Mean age was 70.22 years ± 6.94 (SD). Retinal pathologies were observed in 55.6 % of photographs (age-related macular degeneration: 34.2 %; diabetic retinopathy: 4.2 %; retinal vein occlusion: 3.8 %). Twelve (2.4 %) fundus pictures were non-gradable. The intra-rater agreement for overall retinal pathologies, retinal hemorrhage, and maculopathy were substantial both for the ophthalmologist as well as for the MLOPs. There was moderate inter-rater agreement between the ophthalmologist and the first MLOP on second rating for overall retinal pathologies, [kappa (k); 95 % CI = 0.59 (0.51-0.66)], retinal hemorrhage [k; 95 % CI = 0.60 (0.41-0.78)], and maculopathy [k; 95 % CI = 0.52 (0.43-0.60)]. Inter-rater agreement between the ophthalmologist and the second MLOP for second rating was moderate for overall retinal pathologies [k; 95 % CI = 0.52 (0.44-0.60)], substantial agreement for retinal hemorrhage [k; 95 % CI = 0. 68 (0.52-0.84)], moderate agreement for maculopathy [k; 95 % CI = 0.59 (0.50-0.67)].

CONCLUSION

There is moderate agreement between the MLOPs and the ophthalmologist in grading fundus photographs for retinal hemorrhages and maculopathy.

Retrospective hospital-based analysis of age-related macular degeneration patterns in India: 5-year follow-up

PURPOSE

To provide a detailed analysis of age-related macular degeneration (AMD) with a 5-year follow-up at a Tertiary Eye Care Center in India.

METHODS

In this retrospective institutional study, 408 eyes of 204 subjects (100 males) with a diagnosis of AMD with minimum 5-year follow-up were included. Data collected included demographics, details of the ocular exam, special investigations performed, treatment offered, complications, and systemic diseases, if any.

RESULTS

The median age was 74.24 ± 8.23 years. Median follow-up was 5.77 years. The visual acuity (VA) at baseline and last visit was 0.74 ± 0.12 (Snellen's equivalent 20/100) and 0.54 ± 0.12 logarithm of the minimum angle of resolution (Snellen's equivalent 20/50; P = 0.032) in patients with choroidal neovascular membrane (CNVM). The most common complaint was decreased vision (94.5%). AMD (any stage) was found to be bilateral in 93% of patients at baseline and 197 patients (96.56%) at 5 years. Seventeen eyes had active CNVM (12 of these were occult) at presentation. At baseline, 43 eyes had a disciform scar. Three hundred twenty-one eyes had dry AMD at baseline (geographic atrophy - 12 [3.7%] eyes). Five-year conversion rate into wet AMD and geographic atrophy was 2.87% and 3.12%. Median number of anti-vascular endothelial growth factor injections administered per patient was 2.8 ± 1.2. CNVM bilaterality was low (7.5%).

CONCLUSION

Patients with AMD in India presented later in the course of the disease. Bilateral advanced AMD and geographic atrophy were uncommon. Five-year conversion rate into wet AMD and geographic atrophy was 2.87% and 3.12%.

Population awareness of diabetic eye disease and age related macular degeneration in Nepal: the Bhaktapur Retina Study

BACKGROUND

Diabetic retinopathy (DR) and age-related macular degeneration (AMD) are among the leading causes of visual impairment and blindness in developing countries. This study aims to explore the awareness of these retinal diseases in Nepal.

METHOD

A population based cross-sectional study conducted among individuals 60 years and older from the Bhaktapur district of Nepal. One thousand consecutive subjects were enrolled and subjected to a structured questionnaire.

RESULT

Subject age ranged from 60 to 93 years with a meanof 69.5 years ± 7.1(S.D.). Males and females comprised 45.1 and 55.9 % of the population, respectively. The majority was illiterate (78.2 %), and agriculture was the predominant occupation (79.8 %). 12.1 % were aware of the effect of diabetes on the eye, and among them, 99 % were aware that diabetes was a blinding disease caused by DR.11.5 % of the subjects were aware of DR, and 10.1 % were aware that subjects with diabetes should undergo periodic eye examinations. Only 7.6 % of subjects were aware of AMD.7.5 and 7.4 % were aware about its aggravation with smoking and sunlight exposure, respectively. Younger age group, males, literates, service holders, best corrected visual acuity >0.3 LogMAR, were each significantly associated with an increase in awareness of diabetic retinopathy. Smokers and those with agricultural occupations were less aware regarding AMD. Those with diabetes,with or without DRwere significantly more aware than those not having the disease.

CONCLUSION

Among the Bhaktapur population, awareness of DR and AMD was only 11.5 and7.6 % respectively. Older age groups, females, illiterates, farmers, and those with poor visual acuity were less aware of these blinding diseases. We recommend community-based eye health education programs targeted at raising awareness of these diseases and preventive measures.

Generic and disease-specific estimates of quality of life in macular degeneration: mapping the MacDQoL onto the EQ-5D-3L

PURPOSE

The macular degeneration quality of life (MacDQoL) instrument is a validated condition-specific measure of quality of life in patients with macular degeneration. This paper presents the first mapping algorithm to predict EQ-5D from responses to the MacDQoL instrument.

METHODS

Responses to the MacDQoL and EQ-5D-3L instruments from 482 patients were collected from the IVAN multicentre trial of two alternative drug treatments for neovascular age-related macular degeneration. Regression specifications were estimated using OLS, censored least absolute deviation, Tobit and two-part models. Their predictive performance was assessed using mean squared error. An internal validation sample based on a random selection of 25 % of patients was used to assess the performance of the model estimated on the remaining 75 % of patients.

RESULTS

A two-part model had the best predictive performance on the full sample. The covariates of this model include responses and weighted impact scores for all 23 condition-specific domains of the MacDQoL, and responses to a general MacDQoL quality of life question. The selected models were successful at predicting means and standard deviations of target populations, but prediction is weaker at the upper and lower extremes of the EQ-5D-3L distribution.

CONCLUSION

The mapping algorithms provide a means of predicting EQ-5D-3L index scores from MacDQoL scores, and could facilitate cost-effectiveness analyses when the latter but not the former are available to researchers. Further validation of the performance of the algorithms using external data would provide a means of establishing the robustness of the algorithms.

Relationship between the complement system, risk factors and prediction models in age-related macular degeneration

Studies performed over the past decade in humans and experimental animals have been a major source of information and improved our understanding of how dysregulation of the complement system contributes to age-related macular degeneration (AMD) pathology. Drusen, the hall-mark of dry-type AMD are reported to be the by-product of complement mediated inflammatory processes. In wet AMD, unregulated complement activation results in increased production of angiogenic growth factors leading to choroidal neovascularization both in humans and in animal models. In this review article we have linked the complement system with modifiable and non-modifiable AMD risk factors as well as with prediction models of AMD. Understanding the association between the complement system, risk factors and prediction models will help improve our understanding of AMD pathology and management of this disease.

The association between plasma 25-hydroxyvitamin D and subgroups in age-related macular degeneration: a cross-sectional study

OBJECTIVES

To evaluate potential differences in plasma 25-hydroxyvitamin in subtypes of age-related macular degeneration (AMD), and in patients in Clinical Age-Related Maculopathy Staging (CARMS) group 5 with or without subretinal fibrosis.

METHODS

This single-center cross-sectional study included 178 participants during a period of 20 months. Ninety-five patients belonged to CARMS 5; twelve belonged to CARMS 4; twenty-two belonged to CARMS 2 or 3; and 49 individuals did not have AMD (CARMS 1). Following a structured interview, a detailed bilateral retinal examination was performed and participants were allocated to their respective subgroups in accordance with the Clinical Age-Related Maculopathy Staging system. Plasma 25-hydroxyvitamin D2 and D3 were analyzed using liquid chromatography-tandem mass spectrometry. Genomic DNA was extracted from leukocytes and genotyped for single nucleotide polymorphisms (SNPs) in the vitamin D metabolism. Differences in plasma 25-hydroxyvitamin D were determined in the subgroups as well as between patients in CARMS 5 with or without subretinal fibrosis.

RESULTS

Plasma 25-hydroxyvitamin D was comparable in patients across CARMS groups 1 to 5 (p = 0.83). In CARMS 5, the presence of subretinal fibrosis was associated with significantly lower concentrations of 25-hydroxyvitamin D as compared to the absence of subretinal fibrosis (47.2 versus 75.6 nmol/L, p<0.001). Patients in CARMS 5 with subretinal fibrosis were more likely to have insufficient levels of 25-hydroxyvitamin D compared to patients without subretinal fibrosis (p = 0.006). No association was found between the SNPs rs10877012, rs2228570, rs4588, or rs7041 and AMD subgroups or plasma 25-hydroxyvitamin levels.

CONCLUSIONS

This study suggests that the presence of subretinal fibrosis in patients belonging to CARMS 5 may be associated with a poor vitamin D status. Our observations warrant further investigation into the role of vitamin D in the development of subretinal fibrosis.

Altered expression of CD46 and CD59 on leukocytes in neovascular age-related macular degeneration

PURPOSE

To investigate the expression of the complement regulatory proteins CD46, CD55, and CD59 on peripheral leukocytes in neovascular age-related macular degeneration (AMD).

DESIGN

Prospective, case-control study.

METHODS

Thirty-five unrelated patients with neovascular AMD and 30 control individuals were included in this case-control study. All participants were subjected to a structured interview and detailed imaging (autofluorescence, digital funduscopy, spectral-domain optical coherence tomography, and fluorescein and indocyanine green angiography in patients suspected of having neovascular AMD) was performed. Fresh ethylenediamine-tetraacetic acid blood was obtained and stained with monoclonal antibodies. Using flow cytometry, the percentage of CD14(+) monocytes, CD45(+) lymphocytes, and CD45(+) granulocytes positive for CD46, CD55, and CD59 was determined in patients with neovascular AMD and was compared with that of controls.

RESULTS

We found that the expression of CD46 and CD59 was significantly lower on CD14(+) monocytes in patients with neovascular AMD compared with controls (P = .0070). A significantly lower expression of CD46 on lymphocytes was observed in patients with fibrosis compared with patients without fibrosis (P = .010).

CONCLUSIONS

Our study suggests that neovascular AMD is associated with an inadequate regulation of the complement system, supporting current evidence on the role of complement dysregulation in the pathogenesis of AMD.

Hydroxytyrosol protects against oxidative damage by simultaneous activation of mitochondrial biogenesis and phase II detoxifying enzyme systems in retinal pigment epithelial cells

Studies in this laboratory have previously shown that hydroxytyrosol, the major antioxidant polyphenol in olives, protects ARPE-19 human retinal pigment epithelial cells from oxidative damage induced by acrolein, an environmental toxin and endogenous end product of lipid oxidation, that occurs at increased levels in age-related macular degeneration lesions. A proposed mechanism for this is that protection by hydroxytyrosol against oxidative stress is conferred by the simultaneous activation of two critically important pathways, viz., induction of phase II detoxifying enzymes and stimulation of mitochondrial biogenesis. Cultured ARPE-19 cells were pretreated with hydroxytyrosol and challenged with acrolein. The protective effects of hydroxytyrosol on key factors of mitochondrial biogenesis and phase II detoxifying enzyme systems were examined. Hydroxytyrosol treatment simultaneously protected against acrolein-induced inhibition of nuclear factor-E2-related factor 2 (Nrf2) and peroxisome proliferator-activated receptor coactivator 1 alpha (PPARGC1α) in ARPE-19 cells. The activation of Nrf2 led to activation of phase II detoxifying enzymes, including γ-glutamyl-cysteinyl-ligase, NADPH (nicotinamide adenine dinucleotide phosphate)-quinone-oxidoreductase 1, heme-oxygenase-1, superoxide dismutase, peroxiredoxin and thioredoxin as well as other antioxidant enzymes, while the activation of PPARGC1α led to increased protein expression of mitochondrial transcription factor A, uncoupling protein 2 and mitochondrial complexes. These results suggest that hydroxytyrosol is a potent inducer of phase II detoxifying enzymes and an enhancer of mitochondrial biogenesis. Dietary supplementation of hydroxytyrosol may contribute to eye health by preventing the degeneration of retinal pigment epithelial cells induced by oxidative stress.