Causes of blindness and visual impairment in Latin America

From the diagnosis of infectious keratitis to discriminating fungal subtypes; a deep learning-based study

Infectious keratitis (IK) is a major cause of corneal opacity. IK can be caused by a variety of microorganisms. Typically, fungal ulcers carry the worst prognosis. Fungal cases can be subdivided into filamentous and yeasts, which shows fundamental differences. Delays in diagnosis or initiation of treatment increase the risk of ocular complications. Currently, the diagnosis of IK is mainly based on slit-lamp examination and corneal scrapings. Notably, these diagnostic methods have their drawbacks, including experience-dependency, tissue damage, and time consumption. Artificial intelligence (AI) is designed to mimic and enhance human decision-making. An increasing number of studies have utilized AI in the diagnosis of IK. In this paper, we propose to use AI to diagnose IK (model 1), differentiate between bacterial keratitis and fungal keratitis (model 2), and discriminate the filamentous type from the yeast type of fungal cases (model 3). Overall, 9329 slit-lamp photographs gathered from 977 patients were enrolled in the study. The models exhibited remarkable accuracy, with model 1 achieving 99.3%, model 2 at 84%, and model 3 reaching 77.5%. In conclusion, our study offers valuable support in the early identification of potential fungal and bacterial keratitis cases and helps enable timely management.

Self-reported glaucoma prevalence and related factors, contribution to reported visual impairment, and functional burden in a cross-sectional study in Colombia

PURPOSE

Describe the self-reported prevalence of glaucoma in Colombian older adults, emphasizing the most important risk factors and associated daily-life functional alterations.

METHODS

This a secondary analysis of the Health, Wellness, and Aging survey conducted in the year 2015. Diagnosis of glaucoma was obtained from self-report. Functional variables were assessed through activities of daily living questionnaires. A descriptive analysis followed by bivariate and multivariate regression models adjusting for confounding variables was conducted.

RESULTS

Self-reported prevalence of glaucoma was 5.67%, with higher rate in women, OR 1.22 (1.13-1.40) p = .003, older age OR 1.02 (1.01-1.02) p < .001, and with higher education OR 1.38 (1.28-1.50) p < .001. Glaucoma was independently associated with diabetes OR 1.37 (1.18-1.61) p  < .001 and hypertension 1.26 (1.08-1.46) p = .003. It also showed statistically significant correlations with poor SRH OR 1.15 (1.02-1.32) p < .001, self-reported visual impairment 1.73 (1.50-2.01) p < .001, and impairment in money management OR 1.59 (1.16-2.08) p  = .002, grocery shopping OR 1.57 (1.26-1.96) p < .001 and preparing meals OR 1.31 (1.06-1.63) p  = .013 and having had falls during the last year OR 1.14 (1.01-1.31) p = 0.041.

CONCLUSION

Our findings suggest the self-reported prevalence of glaucoma in older adults in Colombia to be higher than reported data. Glaucoma and visual impairment in older adults represent a public health concern, since glaucoma was associated with adverse outcomes like functional loss and risk of falling, affecting the quality of life and their participation in society.

MyopiaDETR: End-to-end pathological myopia detection based on transformer using 2D fundus images

Background

Automated diagnosis of various retinal diseases based on fundus images can serve as an important clinical decision aid for curing vision loss. However, developing such an automated diagnostic solution is challenged by the characteristics of lesion area in 2D fundus images, such as morphology irregularity, imaging angle, and insufficient data.

Methods

To overcome those challenges, we propose a novel deep learning model named MyopiaDETR to detect the lesion area of normal myopia (NM), high myopia (HM) and pathological myopia (PM) using 2D fundus images provided by the iChallenge-PM dataset. To solve the challenge of morphology irregularity, we present a novel attentional FPN architecture and generate multi-scale feature maps to a traditional Detection Transformer (DETR) for detecting irregular lesion more accurate. Then, we choose the DETR structure to view the lesion from the perspective of set prediction and capture better global information. Several data augmentation methods are used on the iChallenge-PM dataset to solve the challenge of insufficient data.

Results

The experimental results demonstrate that our model achieves excellent localization and classification performance on the iChallenge-PM dataset, reaching AP₅₀ of 86.32%.

Conclusion

Our model is effective to detect lesion areas in 2D fundus images. The model not only achieves a significant improvement in capturing small objects, but also a significant improvement in convergence speed during training.

Inhibition of Toxoplasma gondii by 1,2,4-triazole-based compounds: marked improvement in selectivity relative to the standard therapy pyrimethamine and sulfadiazine

A safer treatment for toxoplasmosis would be achieved by improving the selectivity profile of novel chemotherapeutics compared to the standard therapy pyrimethamine (PYR) and sulfadiazine (SDZ). We previously reported on the identification of the compounds with imidazole-thiosemicarbazide scaffold as potent and selective anti-Toxoplasma gondii (T. gondii) agents. In our current research, we report on the optimisation of this chemical scaffold leading to the discovery cyclic analogue 20 b with s-triazole core structure. This compound displayed prominent CC₃₀ to IC₅₀ selectivity index (SI) of 70.72, making it 160-fold more selective than SDZ, 11-fold more selective than PYR, and 4-fold more selective than trimethoprim (TRI). Additionally, this compound possesses prerequisite drug-like anti-Toxoplasma properties to advance into preclinical development; it showed ability to cross the BBB, did not induce genotoxic and haemolytic changes in human cells, and as well as it was characterised by low cellular toxicity.

Pattern of vitreo-retinal diseases at University of Gondar tertiary eye care and training center, North-West Ethiopia

Objective

Vitreoretinal diseases are common causes of ocular morbidities and blindness. Data on the spectrum of vitreoretinal diseases needs to be studied and known in order to establish appropriate vitreoretinal care setups. The aim of this study was to determine the patterns of vitreoretinal diseases among patients who visited the vitreoretina clinic of University of Gondar Tertiary Eye Care and Training Center, NW Ethiopia (UoG-TECTC).

Methodology

A hospital based cross sectional study was conducted from October/2017-September/2018. All patients who visited the vitreoretinal clinic for the first time during the study period were studied. Data were collected with standardized data extraction format entered into SPSS statistical package Version 20 and analyzed.

Result

A total of 739 new patients who visited the vitreoretinal clinic were included in the study. The mean age was 50.26 +/- 19 years. The age group between 21–60 years accounted for 59.7% of study patients. Male’s accounted for 63.1% and 58.7% of the participants were from urban areas. Bilateral disease was diagnosed in 504 (68.2%) of patients and 220 (29.7%) were bilaterally blind at presentation. Three hundred eighty nine (52.6%) of them had duration of illness six months and above.

Diabetic Retinopathy (DR), Age Related Macular Degeneration (AMD) and Rhegmatoginous Retinal Detachment (RRD) were the top three retinal diseases accounting for 21.3%(196), 17.3% (128) and 12.4% (92) of diagnoses respectively. Systemic comorbidities were found in 44% (325) of the patients with diabetes mellitus, hypertension and hyperlipidemia being the commonest, occurring in 27.8%, 6.3% and 2.8% of study patients respectively. Cataract was the commonest ocular comorbidity seen in 33.5% of study participants.

Conclusion

Vitreoretinal diseases affected a significant number of patients presented to our center and most of the study patients presented late with significant vision loss and blindness. Males were affected more than females and the age group between 21–60 years accounted nearly two-third of study patients. This is the working age group suffering from vision loss from vitreoretinal diseases. DR, AMD and RRD were the commonest retinal pathologies accounting for nearly half of the vitreoretinal diseases and these conditions are treatable either surgically or medically. However, available facilities for the management of these diseases are not adequate at the center. Strengthening the vitreoretinal services of UoG-TECTC with relevant equipment is recommended.

Causes of functional low vision in a Brazilian rehabilitation service

There is limited information on functional low vision (FLV) in Latin America, especially in individuals under 50 years of age. In the present study, we retrospectively evaluated the medical records of 1393 consecutive subjects seen at a Brazilian tertiary rehabilitation service, from February 2009 to June 2016. We collected sociodemographic, clinical data, and information on optical aids and spectacle prescription. Subjects were divided into three age groups: 0 to 14 years old (children), 15 to 49 years old (young adults), and 50 years or older (older adults). The main etiologies leading to FLV in children were cerebral visual impairment (27.9%), ocular toxoplasmosis (8.2%), and retinopathy of prematurity (7.8%). In young adults, retinitis pigmentosa (7.4%) and cone/rod dystrophy (6.5%) were the most frequent, while in older adults, age-related macular degeneration (25.3%) and diabetic retinopathy (18.0%) were the leading causes. Our results indicate that preventable diseases are important causes of FLV in children in the area, and proper prenatal care could reduce their burden. The increasing life expectancy in Latin America and the diabetes epidemic are likely to increase the demand for affordable, people-centered rehabilitation centers, and their integration into health services should be planned accordingly.

Effect of laser photocoagulation, antiangiogenic therapy or a combined treatment on refractive outcomes of newborns with ROP

PURPOSE

To determine the refractive outcome after treatment with laser photocoagulation, intravitreal antiangiogenic injection or both, for the treatment of type 1 ROP and/or aggressive posterior ROP using defocus equivalent terms. These results will be compared with the spherical equivalent (SE) notation in an initial refraction (during the first 3 years after treatment) and in a final evaluation (three years after treatment).

METHODS

Clinical charts review of preterm patients who developed type 1 ROP and/or aggressive posterior ROP who were treated with laser photocoagulation, intravitreal antiangiogenic injection, or both, between January 2007 and December 2014 at Fundación Oftalmológica de Santander were reviewed. Refractive error was evaluated at two different time points in three different treatment groups.

RESULTS

Seventy-seven eyes (56 patients) with ROP diagnosis treated with laser, antiangiogenics or in a combined scheme were included. Median gestational age was 29 weeks (IQR = 3), median birth weight was 1100 (IQR = 335) and mean corrected age at the time of treatment was 37.3 weeks (SD 2.2). Refractive outcomes in SE terms for the first refraction had a median of -0.50 diopters and in defocus terms, 4.00 diopters (D). For the second refraction, -3.00 diopters and 4.00 diopters (D), respectively. Pearson correlation test result for the first measurement was 93% (p = 0.000) and for the second evaluation was 99% (p = 0.000).

CONCLUSIONS

Low birth weight had a statistically significant association to the increase of the refractive outcome. The high correlation between SE and DE for refractive errors allows us to confirm that DE is an appropriate metric to report refractive outcomes in this group of patients due to the presence of combined refractive ametropias.

Prevalence of ocular findings regardless of visual acuity status in older adults from the Brazilian Amazon Region

Recently, it has been recommended that population-based studies report not only frequencies of vision impairment and blindness but also any ocular abnormalities that might lead an individual to seek for eyecare services. The current study aimed to determine prevalence of ocular findings regardless of visual acuity (VA) status in older adults from the Brazilian Amazon Region. Disturbances were grouped into: Eyelids; Anterior Segment; Posterior Segment; Increased intraocular pressure; and Overall Globe. The presence of an ocular finding was considered positive when any abnormality was noted, regardless of VA. Refractive errors were not considered. A total 2384 eligible persons were enumerated and 2041 (85.6%) examined. The prevalence of ocular disturbances in either eye was 87.0% and was associated with male gender, older age, lower education, and rural residence. Overall, main findings were pterygium, cataract, and pinguecula, occurring in 58.8%, 45.4% and 17.4%, respectively. Among individuals with 20/20 VA in both eyes, the most frequent findings were pterygium, pinguecula, and glaucoma cupping, occurring in 47.4%, 31.2% and 6.5%, respectively. The high prevalence of ocular findings observed in this population reinforces that different conditions might not immediately decrease VA but can indicate risk and/or discomfort symptoms and should be considered when planning public health ophthalmic services.

Ophthalmological knowledge of Family Health Network physicians working as first care providers in Brazil

OBJECTIVE

First care providers working in the Brazilian Unified Health System are often physicians from the Family Health Program. Their knowledge on ophthalmology could indicate whether there is a need for training to decrease ophthalmological demands to secondary or tertiary health levels.

METHODS

A cross-sectional observational study based on an electronic questionnaire was conducted to evaluate the ophthalmological knowledge of Family Health Program physicians working at the VI Regional Health Department, Sao Paulo, Brazil. All Family Health Program physicians from this regional health department were invited, and the study included those who responded to the full questionnaire (115 physicians). The data were evaluated using descriptive analysis.

RESULTS

There was no difference in the ophthalmological knowledge between sexes or in relation to undergraduate schools. Only 20% of the interviewees were specialized in Family and Community Medicine, which did not influence the number of correct answers. Only 22 (19.1%) physicians reported having enough knowledge about the main eye disorders, and 82 (71.3%) physicians considered themselves capable of treating ophthalmological emergencies. However, acute glaucoma was recognized by only 51 (44.3%) physicians, and eye perforations could only be handled by 65 (56.5%) of them. In addition, only 47 (40.9%) participants correctly answered that congenital cataracts should be operated right after diagnosis.

CONCLUSIONS

Family Health Program physicians working as first care providers in the Health System in Brazil presented poor ophthalmological knowledge. Providing training on ophthalmology may improve the ophthalmological care at the primary level within SUS and reduce the case demands at other healthcare levels.

Epidemiological Surveillance of Eye Disease and People Awareness in the Abruzzo Region, Italy

Background and Objectives: Vision impairments and related blindness are major public health problems. The prevalence of eye disease and barriers to optimal care markedly vary among different geographic areas. In the Abruzzo region (central Italy), an epidemiological surveillance on the state of ocular health in the population aged over 50 years was performed in 2019. Materials and Methods: Participants were sampled to be representative of the region’s inhabitants. Data were collected through a telephone interview and an eye examination. Prevalence of cataract, glaucoma, retinopathy, and maculopathy was assessed. The Cohen’s kappa (k) was used to measure the agreement between the presence of eye disease and awareness of the disease by the participants. Results: Overall, 983 people with a mean age of 66.0 ± 9.5 years were included in the study. The prevalence of cataracts, glaucoma, maculopathy, and retinopathy was 52.6%, 5.3%, 5.6%, and 29.1%, respectively. Among the total of the affected people, those aware of their condition were 21.8% (k = 0.12, slight agreement) for cataract, 65.4% (k = 0.78, substantial agreement) for glaucoma, 7.1% (k = 0.10, slight agreement) for maculopathy, and 0% for retinopathy (k = −0.004, agreement lower than that expected by chance). Refractive defects were corrected in the vast majority of participants. Conclusion: In the Abruzzo region, about two thirds of citizens aged 50 years or over suffer from cataract, glaucoma, retinopathy, or maculopathy, which are recognized as leading causes of blindness. Many people with eye disease do not know they have it. These data can be used by clinicians and policymakers to undertake clinical, political, and social actions.

Toxoplasma gondii in domiciled dogs and cats in urban areas of Brazil: risk factors and spatial distribution

Toxoplasma gondii is a highly prevalent zoonotic parasite in Brazil capable of infecting mammals and birds. The increase in the urban populations of pets and the narrowing of the human-animal relationship can facilitate the transmission of important public health zoonoses, such as toxoplasmosis. This study aimed to evaluate the frequency and spatial distribution of T. gondii infection and its risk factors in domiciled dogs and cats attended at the Jorge Vaitsman Institute, Rio de Janeiro. Serum samples from 400 dogs and 272 cats were evaluated by an indirect fluorescent antibody test (IFAT) for IgG anti-T. gondii antibodies. Epidemiological questionnaires were used to interview the animals' owners to identify risk factors for infection. Of the total, 34% (136/400) of dogs and 8.1% (22/272) of cats had anti-T. gondii antibodies. Breed (OR: 2.10-95%, CI 1.27-3.46) was a risk factor for dogs, while sex (OR: 3.40-95%, CI 1.10-10.52) and homemade food consumption (OR: 8.49-95%, CI 2.48-29.05) were risk factors for cats. Offal consumption was considered a risk factor for both species evaluated (OR: 2.74-95%, CI 1.38-5.43 for dogs; OR: 7.66-95%, CI 1.24-47.29 for cats). The spatial analysis showed that T. gondii seropositive animals were widely distributed in the metropolitan region of Rio de Janeiro state, with a concentration observed mainly in the west and north zones of Rio de Janeiro city. The results emphasize the importance of adopting prophylactic measures to control T. gondii transmission in domiciled dogs and cats in Rio de Janeiro, contributing positively to public health.

Cataract as a Cause of Blindness and Vision Impairment in Latin America: Progress Made and Challenges Beyond 2020

PURPOSE

To provide an update of cataract as a cause of vision loss in Latin America and to analyze sex inequalities in cataract surgical coverage (CSC) and effective CSC (eCSC) in the region.

DESIGN

Population-based systematic review with longitudinal comparisons.

METHODS

The Latin American and Caribbean Health Sciences Literature (LILACS) and PubMed databased were searched for population-based studies reporting cataract blindness, surgical coverage, and outcomes published between January 2014 and December 2019. Information on the number of surgeries performed from the 2014-2016 period was obtained from ministries of health and was used for calculation of the cataract surgical rate (CSR). Sources such as Rapid Assessment of Avoidable Blindness (RAAB) and Rapid Assessment of Cataract Surgical Services data were reanalyzed to calculate sex inequality in CSC and eCSC by subtracting the rate in women from the rate in men.

RESULTS

Cataract was the cause of 29.8%-77.6% of cases of blindness in the included studies; the CSR improved in 10 countries. The CSC pinhole visual acuity of 3/60 varied from 24.1% in Peru to 97.1% in Argentina, and the median absolute gender inequality CSC pinhole visual acuity 3/60 was -0.7%. The eCSC pinhole visual acuity 3/60 varied from 14.8% in Guatemala to 92.1% in Argentina, and the median absolute gender inequality eCSC pinhole visual acuity 3/60 was -0.8%.

CONCLUSIONS

Cataract remains a leading cause of blindness in Latin America. Coverage is suboptimal, and surgical results are also below target levels in many countries. Incentives for a better distribution of human resources, adequate training of ophthalmologists, and the inclusion of vision services in universal health care coverage could reduce the burden of cataract in Latin America.

Frequency and visual outcomes of ocular toxoplasmosis in an adult Brazilian population

Although ocular toxoplasmosis is a leading cause of posterior uveitis worldwide, there is scarce information about the real-life frequency of ocular lesions, visual outcomes, and risk factors for poor prognosis. We conducted a community-based cross-sectional study with 721 adults living in Cássia dos Coqueiros, Southeast Brazil, consisted of visual acuity measurement, dilated ocular examination, a risk-factor questionnaire, and peripheral blood collection for anti-T. gondii serology. Presumed toxoplasmic lesions were recorded on video and analyzed by experienced and masked ophthalmologists. Ocular toxoplasmosis was determined if at least one suspected lesion was appointed by two graders in the presence of positive anti-T. gondii serology. Forty-eight eyes (n = 42 participants; 6.7% among those with positive anti-T. gondii serology) with ocular toxoplasmosis were found. Most lesions were single (n = 28; 58.3%), peripheral (n = 34; 77.1%) and unilateral (85.7% of participants); no active lesions were found. Older age was associated with lesions larger than one-disc diameter (p = 0.047), and lower social stratum (OR: 2.89; CI 1.2-6.97; p = 0.018) was associated with the presence of toxoplasmic lesions. Although there were no differences in visual acuity between participants and eyes with or without ocular lesions (p > 0.05), unilateral blindness associated with ocular toxoplasmosis was identified in a reduced number of individuals.

Clinical manifestations and visual outcomes associated with ocular toxoplasmosis in a Brazilian population

Ocular toxoplasmosis is the leading cause of posterior uveitis worldwide. We conducted an observational study of 262 consecutive individuals (n = 344 eyes) with ocular toxoplasmosis who were followed over a 34-month period. Most subjects were T. gondii IgG + /IgM- (n = 242; 92.4%; 317 eyes), and 140 eyes (40.7%) had active lesions. For eyes in which retinal lesions were active at recruitment and best-corrected visual acuity (BCVA) could be measured (n = 133), 21.0% (n = 28) remained blind (BCVA below 20/400) after inflammation resolved. In these eyes, atypical ocular toxoplasmosis (OR 4.99; 95% CI 1.14–22.85; p = 0.0330), macular lesion (OR 9.95; 95% CI 2.45–47.15; p = 0.0019) and any complication (OR 10.26; 95% CI 3.82–30.67; p < 0.0001) were associated with BCVA below 20/200. For eyes with only inactive lesions at recruitment and BCVA measured (n = 178), 28.1% (n = 50) were blind. In these eyes, having at least one lesion larger than one disc-diameter (OR 6.30; 95% CI 2.28–22.46; p = 0.0013) and macular lesion (OR 5.69; 95% CI 2.53–13.54; p < 0.0001) were associated with BCVA below 20/200. Older age (OR 1.02; 95% CI 1.00–1.05; p = 0.0493) and active disease at presentation (OR 4.74; 95% CI 1.95–12.91; p = 0.0011) were associated with recurrences. Additional clinical attention should be directed towards patients with risk factors for poor visual outcome.

Causes of Blindness and Visual Impairment in Early Childhood at a Low Vision Service in Mexico City: A 15-year Review

Purpose: To evaluate the causes of blindness and visual impairment in children aged 0-7 years attending a Low Vision Centre in Mexico City, Mexico.Methods: Clinical records for patients aged 0-7 years attending the Centre from 2001 to 2015 were retrospectively reviewed. Causes of blindness and visual impairment, affected anatomy, and suspected time period of insult were recorded.Results: 1487 patients were included, 45.9% girls and 54.1% boys. Mean age of presentation was 39 months (SD 27.9 months). 36.0% had associated co-morbidities in addition to their ophthalmic pathology. 39.7% presented with developmental or psychomotor delay. Leading diagnoses were Retinopathy of Prematurity (ROP) (19.6%), optic nerve atrophy (11.5%), and congenital cataract (9.5%). The most affected anatomical regions were retina (33.8%), optic nerve (16.6%), and lens (10.5%). Half of all cases (50.9%) had insults in the prenatal period. Children with developmental delay were more likely to present before the age of one. There is a significant difference in risk of delayed presentation according to diagnosis. Only 13.5% of children with optic nerve atrophy presented to the Centre before the age of one, compared to 28.4% of children with ROP and 23.4% of children with cataract.Conclusion: The most common diagnoses for blindness and visual impairment among children were ROP, optic nerve atrophy, and congenital cataract. Late presentation to the Centre was common. There were significant differences in risk of delayed presentation depending on diagnosis. Co-existing systemic conditions and developmental and psychomotor delay were also common among patients attending the Centre.

Cost-Utility Analysis of Wide-Field Imaging as an Auxiliary Technology for Retinopathy of Prematurity Care in Brazil

Purpose: To evaluate the cost-utility of wide-field imaging (WFI) as a complementary technology for retinopathy of prematurity (ROP) screening from the Brazilian Unified Health System's perspective. Introduction: ROP is one of the leading causes of avoidable childhood blindness worldwide, especially in middle-income countries. The current ROP screening involves indirect binocular ophthalmoscopy (IBO) by ROP expert ophthalmologists. However, there is still insufficient ROP screening coverage. An alternative screening strategy is the combination of WFI with IBO. Methods: A cost-utility analysis was performed using a deterministic decision-tree simulation model to estimate incremental cost-utility for ROP care. Two screening strategies were compared: (1) IBO and (2) combination of WFI of all eligible preterm infants and IBO for type 2 ROP or worse and for non-readable images. Eligible population included preterm infants <32 weeks of gestational age or birth weight equal to or <1,500 g. The temporal horizon was lifetime. Visual outcome data was converted to utility, and the health benefits were estimated on quality-adjusted life-years (QALY). Incremental cost per QALY gained was calculated from the health system perspective. Costs were estimated considering equipment, maintenance, consumables, and staff. A micro-costing approach was used for WFI. Two technician nurses were trained for imaging execution and had their time evaluated. Two ROP expert ophthalmologists had their time evaluated for imaging reading. One-way sensitivity analysis and probabilistic sensitivity analysis were performed. Results: Combined screening strategy resulted in a cost-effective program considering 90% ROP screening coverage. Costs per examination: (1) screening with IBO: US dollar (US $) 34.36; (2) screening with combination: US $58.20; (3) laser treatment: US $642.09; (4) long-term follow-up: ranged from US $69.33 to 286.91, based on the infant's visual function. Incremental cost per QALY gained was US $1,746.99/QALY per infant screened with the combination strategy. One-way sensitivity analysis resulted in cost-effectiveness for all parameters. Probabilistic sensitivity analyses yielded a 100% probability of combination being cost-effective in a willingness-to-pay threshold of US $1,800/QALY. Conclusion: The combined strategy for ROP screening was cost-effective. It enhances access for appropriate ROP care in middle-income countries and dminishes opportunity costs for ophthalmologists.

Pathogenesis of ocular toxoplasmosis

Ocular toxoplasmosis is a retinitis -almost always accompanied by vitritis and choroiditis- caused by intraocular infection with Toxoplasma gondii. Depending on retinal location, this condition may cause substantial vision impairment. T. gondii is an obligate intracellular protozoan parasite, with both sexual and asexual life cycles, and infection is typically contracted orally by consuming encysted bradyzoites in undercooked meat, or oocysts on unwashed garden produce or in contaminated water. Presently available anti-parasitic drugs cannot eliminate T. gondii from the body. In vitro studies using T. gondii tachyzoites, and human retinal cells and tissue have provided important insights into the pathogenesis of ocular toxoplasmosis. T. gondii may cross the vascular endothelium to access human retina by at least three routes: in leukocyte taxis; as a transmigrating tachyzoite; and after infecting endothelial cells. The parasite is capable of navigating the human neuroretina, gaining access to a range of cell populations. Retinal Müller glial cells are preferred initial host cells. T. gondii infection of the retinal pigment epithelial cells alters the secretion of growth factors and induces proliferation of adjacent uninfected epithelial cells. This increases susceptibility of the cells to parasite infection, and may be the basis of the characteristic hyperpigmented toxoplasmic retinal lesion. Infected epithelial cells also generate a vigorous immunologic response, and influence the activity of leukocytes that infiltrate the retina. A range of T. gondii genotypes are associated with human ocular toxoplasmosis, and individual immunogenetics -including polymorphisms in genes encoding innate immune receptors, human leukocyte antigens and cytokines- impacts the clinical manifestations. Research into basic pathogenic mechanisms of ocular toxoplasmosis highlights the importance of prevention and suggests new biological drug targets for established disease.

Validation of an IGF1 Screening Method for Retinopathy of Pre-maturity

Retinopathy of pre-maturity (ROP) is a retinal disease that causes arrest of vascularization of the retina and can result in retinal detachment and blindness. Current screening protocols may not be sufficiently accurate to identify all at-risk patients. The aim of this study is to validate a method for improved identification of newborns at risk of ROP. We conducted a prospective clinical trial of pre-term newborns <32 weeks of gestation and/or <1,500 g birth weight during a 6-year period in a tertiary care hospital. We applied our new method based on measurement of insulin-like growth factor 1 (IGF1) levels at 3 weeks of age and the presence of sepsis during the first 3 weeks of life. Our screening protocol allowed exclusion of 121 (79.1%) patients for whom American Academy of Pediatrics (AAP) guidelines recommended screening, had a negative predictive value of 100%, and correctly identified all patients with ROP. Following retrospective assessment of our data based on these findings, we propose further restriction of the current AAP indications for screening to <1,100 g and <28 weeks of gestation in order to improve diagnostic efficacy while ensuring optimal use of restriction of human and material resources.

Visual impairment among adults in Saudi Arabia

BACKGROUND

To estimate the prevalence of visual impairment, and identify its causes and associated factors among adults aged 40 years and over, attending for eye examination at a Riyadh public hospital in Saudi Arabia.

METHODS

This was a retrospective cross-sectional study conducted among 195 consecutive older adults who attended the outpatient ophthalmology clinic of King Abdul-Aziz University Hospital between 1 February and 30 June 2018. All participants underwent comprehensive ophthalmic examination: visual acuity, refraction (objective and subjective), fundus photography and automated visual field assessment. Classification of visual impairment was based on the World Health Organization criteria: mild visual impairment if best-corrected distance visual acuity < 6/12-6/18 in the better eye; moderate visual impairment if best-corrected visual acuity < 6/18-6/60 in the better eye; and severe visual impairment if best-corrected visual acuity < 6/60-3/60. Regression analysis was used to identify the factors associated with visual impairment.

RESULTS

The study participants included 107 (54.9 per cent) females, and the mean (SD) age was 61.1 ± 10.9 years. The overall prevalence of visual impairment (14.9 per cent, 29 cases), consisting of severe (0.5 per cent), moderate (9.7 per cent) and mild (4.6 per cent) forms, correlated significantly with age (R² = 0.023, p = 0.04). The main causes of visual impairment were glaucoma (48.3 per cent), cataract (31.0 per cent), refractive error, and diabetic retinopathy (24.1 per cent each). The odds of having visual impairment increased by 22 per cent and eight per cent respectively in participants who had diabetic retinopathy (adjusted odds ratio 1.22, 95% confidence interval [CI] 1.05, 1.95) and glaucoma (1.08, CI 1.02, 1.40).

CONCLUSIONS

The prevalence of visual impairment among older adults attending the ophthalmology clinic in Riyadh city was high and driven by the high rate of diabetic retinopathy and glaucoma in this region. As part of their routine checks, there is need to make dilated fundus examination and intraocular pressure measurement mandatory tests in addition to refraction and visual acuity testing, when examining Saudi adults attending the hospital eye clinics in Riyadh province.

Population-Based Cataract Surgery Complications and Their Impact on Visual Status in the Brazilian Amazon Region

PURPOSE

To investigate cataract surgery prevalence, complications, visual outcomes, and coverage in a population of older adults from the Brazilian Amazon region.

DESIGN

Population-based cross-sectional study.

METHODS

Individuals ≥45 years of age from urban and rural areas of Parintins City, Brazil, were identified by cluster random sampling. Participants underwent ophthalmic examination, including uncorrected visual acuity, acuity with presenting correction (APC), and best-corrected visual acuity (BCVA) from each eye. In those with previous cataract surgery, surgical technique and complications including its contribution to vision impairment were noted. The association of surgical complications and surgical coverage with sociodemographic variables was assessed by multiple logistic regression.

RESULTS

A total of 2,384 persons were determined to be eligible, and 2,041 (85.6%) were examined. Overall, prevalence of cataract surgery was 8.6%, with 11.3% urban and 5.0% rural. Surgical complications were associated with males, older age, and urban residency and were found in 60.4%, with posterior capsule opacification in 29.6% and posterior capsule rupture in 16.3%. Among the 270 eyes having cataract surgery, APC ≥20/32 was found in 44.4%, APC 20/40 to 20/63 in 20.8%, APC <20/63 to 20/200 in 14.4%, APC <20/200 to 20/400 in 2.6%, and APC <20/400 in 17.8%. Low surgical coverage was found with 57.9% of those with visual impairment due to cataract not being treated surgically.

CONCLUSIONS

Although a reasonable prevalence of cataract surgery was found, a high complication rate, poor visual outcomes, and low cataract surgery coverage indicated that actions to improve quality and appropriate postsurgical management should be planned and implemented by public health authorities.

Evaluation of a Tele-assistance Technological Tool in Activities of Daily Life of People with Visual Disabilities

Introduction:

Blind people lose an important degree of independence, which makes it difficult to carry out different activities of daily life.

Objective:

To develop and evaluate a telecare model that consisted of guiding a person with visual disability through a video conference to carry out activities of daily life.

Methods:

The telecare model is based on the guidance through voice commands. Telecare begins when a blind person, through a mobile device, transmits images, video and voice (video conference) in real-time to a person with normal vision in a different place that works as a guide, so that the guide knows the details of the blind person. The environment of the person that can solve immediate information needs, location or selection of objects requires visual support. It was evaluated with 37 people with visual disabilities through the Lawton & Brody scale.

Results:

It is an improved progressive evolution in the level of independence of the Lawton and Brody scale, which presents an advance of just over 2 points in the scale thanks to the tele-assistance application (p = 0.000).

Conclusion:

The participants were at a moderate level of dependence and, after the tele-assistance tests, their level was mild. The highest score was obtained in activities related to money management and purchases. In contrast, participants had less value activities within the home. The results allowed us to verify the effectiveness of telecare to improve the independence and well-being of people with visual disabilities.

Changes in mitochondrial cytochrome c oxidase mRNA levels with cataract severity in lens epithelia of Japanese patients

We previously reported that the collapse of ATP production via mitochondrial damage causes ATPase dysfunction, resulting in the onset or progression of lens opacification in cataracts in model rats. In the present study, it was investigated whether the mRNA expression levels of the three subtypes of mitochondrial cytochrome c oxidase (MTCO)1, 2 and 3 and ATP content change with the type and severity of cataracts in human lens. Samples of lens epithelium were collected from Japanese patients during cataract surgery, and the type and severity of the cataracts (grade) were determined according to the WHO classification [cortical (COR), nuclear (NUC), posterior subcapsular (PSC) opacification]. The MTCO1‑3 mRNA expression levels in patients with grade‑1 COR, NUC and PSC opacification were significantly enhanced compared with those of normal patients. The enhanced MTCO1‑3 mRNA levels subsequently decreased in patients with COR, and the MTCO1‑3 mRNA levels and ATP levels in patients with grade‑3 COR were similar to those in normal patients. However, the mRNA expression levels of MTCO3 in patients with grade 3‑NUC opacification and MTCO1‑3 in patients with grade‑3 PSC opacification, along with the ATP content, were significantly lower than in patients without cataracts. In conclusion, it was revealed that ATP production in lens epithelium is enhanced in early‑stage cataracts (grade‑1) in Japanese patients with COR, NUC and PSC opacification. In addition, in severe cataracts (grade‑3), ATP production and content are strongly decreased in Japanese patients with PSC opacification. ATP depletion in human lens epithelium with PSC opacification may promote lens opacification by ATPase dysfunction.

AAV2-mediated GRP78 Transfer Alleviates Retinal Neuronal Injury by Downregulating ER Stress and Tau Oligomer Formation

Purpose

Retinal ganglion cell (RGC) death following axonal injury occurring in traumatic optic neuropathy (TON) causes irreversible vision loss. GRP78 is a molecular chaperone that enhances protein folding and controls activation of endoplasmic reticulum (ER) stress pathways. This study determined whether adeno-associated virus (AAV)-mediated gene transfer of GRP78 protected RGCs from death in a mouse model of TON induced by optic nerve crush (ONC).

Methods

ONC was induced by a transient crush of optic nerve behind the eye globe. AAV was used to deliver genes into retina. Molecules in the ER stress branches, tau oligomers, and RGC injury were determined by immunohistochemistry or Western blot.

Results

Among tested AAV serotypes, AAV2 was the most efficient for delivering genes to RGCs. Intravitreal delivery of AAV2-GRP78 markedly attenuated ER stress and RGC death 3 days after ONC, and significantly improved RGC survival and function 7 days after ONC. Protein aggregation is increased during ER stress and aggregated proteins such as tau oligomers are key players in neurodegenerative diseases. AAV2-GRP78 alleviated ONC-induced increases in tau phosphorylation and oligomerization. Furthermore, tau oligomers directly induced RGC death, and blocking tau oligomers with tau oligomer monoclonal antibody (TOMA) attenuated ONC-induced RGC loss.

Conclusion

These data indicate that the beneficial effect of AAV2-GRP78 is partially mediated by the reduction of misfolded tau, and provide compelling evidence that gene therapy with AAV2-GRP78 or immunotherapy with TOMA offers novel therapeutic approaches to alleviate RGC loss in TON.

A high prevalence of biallelic RPE65 mutations in Costa Rican children with Leber congenital amaurosis and early-onset retinal dystrophy

BACKGROUND

Leber congenital amaurosis (LCA) and early-onset retinal dystrophy (EORD), are primary causes of inherited childhood blindness. Both are autosomal recessive diseases, with mutations in more than 25 genes explaining approximately ~70% of cases. However, the genetic cause for many cases remains unclear. Sequencing studies from genetically isolated populations with increased prevalence of a disorder has proven useful for rare variant studies, making Costa Rica an ideal place to study LCA/EORD genetics.

MATERIALS AND METHODS

Twenty-eight affected children (25 LCA, three EORD) and their immediate family members, totaling 52 individuals (30 affected) from 22 families, were sequenced. Whole exome sequencing was performed on all affected individuals. Available parents were analyzed either by whole exome sequencing (WES) or Sanger sequencing to determine transmission.

RESULTS

All affected individuals demonstrated compound heterozygous or homozygous mutations in known Inherited Retinal Disease (IRD) associated genes. Twelve variants were identified in at least one individual in three genes, RDH12, RPE65, and USH2A. Four recurrent RPE65 mutations were observed in 97% of individuals and 95% of families. All patients with LCA and two of the three individuals with EORD had biallelic mutations in RPE65; one child with EORD had a homozygous RDH12 mutation.

CONCLUSIONS

These data suggest that the majority of LCA/EORD in Costa Rica is due to four founder mutations in RPE65 which have been maintained in this genetically isolated population. This finding is of great clinical significance due to the availability of gene therapy recently approved in the US and European Union for patients with biallelic RPE65 defects.

Enteral Docosahexaenoic Acid and Retinopathy of Prematurity: A Randomized Clinical Trial

BACKGROUND

Retinopathy of prematurity (ROP) is a disorder of the retina of low-birth-weight preterm infants that potentially leads to blindness. Docosahexaenoic acid (DHA), is protective in experimental models, but its administration as part of parenteral nutrition has shown inconsistent results. We test the effect of enteral DHA to prevent ROP and/or severity and to reduce hospital stay.

METHODS

This was a double-blind parallel clinical trial. Preterm infants (n = 110; 55 per group) with birth weight <1500 g but ≥1000 g were recruited in a neonatal intensive care unit. Infants were randomized to receive 75 mg of DHA/kg/d (DHA group) or high oleic sunflower oil (control group) for 14 days by enteral feeding. The effect of DHA was evaluated on any stage of ROP, severe ROP (stage ≥3) incidence, and hospital stay. Groups were compared with relative risk (RR) and 95% confidence interval (CI), Fisher's exact test, Student's t-test, or Mann-Whitney U-test, as appropriate. Logistic regression was applied to adjust for confounders.

RESULTS

There was no difference between the DHA and control groups in ROP risk (RR for DHA = 0.79; 95% CI, 0.49-1.27; P = 0.33). However, patients who received DHA showed lower risk for stage 3 ROP (RR for DHA = 0.66; 95% CI, 0.44-0.99; P = 0.03). After adjusting for confounders, this decreased risk remained significant (adjusted odds ratio = 0.10; 95% CI, 0.011-0.886; P = 0.04). Hospital stay was similar between groups.

CONCLUSION

Enteral DHA may reduce the incidence of stage 3 ROP.

Prevalence and causes of vision loss in Latin America and the Caribbean in 2015: magnitude, temporal trends and projections

OBJECTIVE

To estimate the prevalence and causes of blindness and vision impairment for distance and near in Latin America and the Caribbean (LAC) in 2015 and to forecast trends to 2020.

METHODS

A meta-analysis from a global systematic review of 283 cross-sectional, population-representative studies from published and unpublished sources from 1980 to 2014 in the Global Vision Database included 17 published and 6 unpublished studies from LAC.

RESULTS

In 2015, across LAC, age-standardised prevalence was 0.38% in all ages and 1.56% in those over age 50 for blindness; 2.06% in all ages and 7.86% in those over age 50 for moderate and severe vision impairment (MSVI); 1.89% in all ages and 6.93% in those over age 50 for mild vision impairment and 39.59% in all ages and 45.27% in those over 50 for near vision impairment (NVI). In 2015, 117.86 million persons were vision impaired; of those 2.34 million blind, 12.46 million with MSVI, 11.34 million mildly impaired and 91.72 million had NVI. Cataract is the most common cause of blindness. Undercorrected refractive-error is the most common cause of vision impairment.

CONCLUSIONS

These prevalence estimates indicate that one in five persons across LAC had some degree of vision loss in 2015. We predict that from 2015 to 2020, the absolute numbers of persons with vision loss will increase by 12% to 132.33 million, while the all-age age-standardised prevalence will decrease for blindness by 15% and for other distance vision impairment by 8%. All countries need epidemiologic research to establish accurate national estimates and trends. Universal eye health services must be included in universal health coverage reforms to address disparities, fragmentation and segmentation of healthcare.

Refractive error and ocular findings among infants and young children with severe problem behavior and developmental disabilities

The prevalence of refractive error and ocular disorders among infants and young children with severe behavioral problems and developmental disorders is not well defined, particularly in developing countries. We performed a retrospective review of ophthalmic examinations performed during a National Institutes of Health-funded cohort study of very young children in Peru with behavioral problems and at risk for developmental disorders. 222 children between the ages of 0 and 4 years (mean 2.2 ± 0.9 years) were examined and 100 (45.0%) had an abnormal ocular exam. Overall, the prevalence of refractive error was 33.3%, nystagmus was 12.2%, and strabismus was 10.9%. Among children with Down syndrome, refractive error ranged from 46.2% at age 2 to 85.7% at age 4. Refractive error and ocular disorders are highly prevalent even at a young age in children with behavioral problems and developmental disorders. Much of the visual impairment in this population is treatable; early identification and intervention can have a lifelong positive impact on neurodevelopment.

Avoidable Waste in Ophthalmic Epidemiology: A Review of Blindness Prevalence Surveys in Low and Middle Income Countries 2000-2014

PURPOSE

Sources of avoidable waste in ophthalmic epidemiology include duplication of effort, and survey reports remaining unpublished, gaining publication after a long delay, or being incomplete or of poor quality. The aim of this review was to assess these sources of avoidable waste by examining blindness prevalence surveys undertaken in low and middle income countries (LMICs) between 2000 and 2014.

METHODS

On December 1, 2016 we searched MEDLINE, EMBASE and Web of Science databases for cross-sectional blindness prevalence surveys undertaken in LMICs between 2000 and 2014. All surveys listed on the Rapid Assessment of Avoidable Blindness (RAAB) Repository website ("the Repository") were also considered. For each survey we assessed (1) availability of scientific publication, survey report, summary results tables and/or datasets; (2) time to publication from year of survey completion and journal attributes; (3) extent of blindness information reported; and (4) rigour when information was available from two sources (i.e. whether it matched).

RESULTS

Of the 279 included surveys (from 68 countries) 186 (67%) used RAAB methodology; 146 (52%) were published in a scientific journal, 57 (20%) were published in a journal and on the Repository, and 76 (27%) were on the Repository only (8% had tables; 19% had no information available beyond registration). Datasets were available for 50 RAABs (18% of included surveys). Time to publication ranged from <1 to 11 years (mean, standard deviation 2.8 ± 1.8 years). The extent of blindness information reported within studies varied (e.g. presenting and best-corrected, unilateral and bilateral); those with both a published report and Repository tables were most complete. For surveys published and with RAAB tables available, discrepancies were found in reporting of participant numbers (14% of studies) and blindness prevalence (15%).

CONCLUSION

Strategies are needed to improve the availability, consistency, and quality of information reported from blindness prevalence surveys, and hence reduce avoidable waste.

Using the STROBE statement to assess reporting in blindness prevalence surveys in low and middle income countries

Objective

Cross-sectional blindness prevalence surveys are essential to plan and monitor eye care services. Incomplete or inaccurate reporting can prevent effective translation of research findings. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement is a 32 item checklist developed to improve reporting of observational studies. The aim of this study was to assess the completeness of reporting in blindness prevalence surveys in low and middle income countries (LMICs) using STROBE.

Methods

MEDLINE, EMBASE and Web of Science databases were searched on April 8 2016 to identify cross-sectional blindness prevalence surveys undertaken in LMICs and published after STROBE was published in December 2007. The STROBE tool was applied to all included studies, and each STROBE item was categorized as ‘yes’ (met criteria), ‘no’ (did not meet criteria) or ‘not applicable’. The ‘Completeness of reporting (COR) score’ for each manuscript was calculated: COR score = yes / [yes + no]. In journals with included studies the instructions to authors and reviewers were checked for reference to STROBE.

Results

The 89 included studies were undertaken in 32 countries and published in 37 journals. The mean COR score was 60.9% (95% confidence interval [CI] 58.1–63.7%; range 30.8–88.9%). The mean COR score did not differ between surveys published in journals with author instructions referring to STROBE (10/37 journals; 61.1%, 95%CI 56.4–65.8%) or in journals where STROBE was not mentioned (60.9%, 95%CI 57.4–64.3%; p = 0.93).

Conclusion

While reporting in blindness prevalence surveys is strong in some areas, others need improvement. We recommend that more journals adopt the STROBE checklist and ensure it is used by authors and reviewers.

Local Group 2 Innate Lymphoid Cells Promote Corneal Regeneration after Epithelial Abrasion

Corneal injuries and infections are the leading cause of blindness worldwide. Thus, understanding the mechanisms that control healing of the damaged cornea is critical for the development of new therapies to promptly restore vision. Innate lymphoid cells (ILCs) are a recently identified heterogeneous cell population that has been reported to orchestrate immunity and promote tissue repair in the lungs and skin after injury. However, whether ILCs can modulate the repair process in the cornea remains poorly understood. We identified a population of cornea-resident group 2 ILCs (ILC2s) in mice that express CD127, T1/ST2, CD90, and cKit. This cell population was relatively rare in corneas at a steady state but increased after corneal epithelial abrasion. Moreover, ILC2s were maintained and expanded locally at a steady state and after wounding. Depletion of this cell population caused a delay in corneal wound healing, whereas supplementation of ILC2s through adoptive transfer partially restored the healing process. Further investigation revealed that IL-25, IL-33, and thymic stromal lymphopoietin had critical roles in corneal ILC2 responses and that CCR2^- corneal macrophages were an important producer of IL-33 in the cornea. Together, these results reveal the critical role of cornea-resident ILC2s in the restoration of corneal epithelial integrity after acute injury and suggest that ILC2 responses depend on local induction of IL-25, IL-33, and thymic stromal lymphopoietin.

Prevalence and causes of visual impairment among Saudi adults

Objective:

To evaluate the prevalence and causes of visual impairment (VI) among Saudi adults in Arar City, the capital of Northern Border Region of Saudi Arabia.

Methods:

This population-based cross-sectional study was conducted on 705 Saudi adults aged 18 years and older. All participants underwent ophthalmic examination including visual acuity (VA) testing, auto refraction, intraocular pressure (IOP) measurement and fundus examination.

Results:

In the present study 166 cases (23.5%) were found to have VI, while only 12 cases (1.7%) were considered as blind following the WHO definitions. Cataract was found to be the main cause of VI [51 cases (30.7%)] followed by refractive error (RE) [41 cases (24.7%)] and diabetic retinopathy (DR) [22 cases (13.2%)]. Seventy one cases of the studied subjects (10.07 %) had shown unilateral VI, while 13 cases (1.8%) had shown unilateral blindness with the other eye normal (VA ≥ 20/20).

Conclusion:

Visual impairment is highly prevalent among Saudi adults in Arar city. Cataract, refractive error and diabetic retinopathy are the main 3 leading causes. Better plans for diagnosis and treatment should be considered to decrease the magnitude of the problem.

Neuroprotective effects of BDNF and GDNF in intravitreally transplanted mesenchymal stem cells after optic nerve crush in mice

AIM

To assess the neuro-protective effect of bone marrow mesenchymal stem cells (BMSCs) on retinal ganglion cells (RGCs) following optic nerve crush in mice.

METHODS

C56BL/6J mice were treated with intravitreal injection of PBS, BMSCs, BDNF-interference BMSCs (BIM), and GDNF-interference BMSCs (GIM) following optic nerve crush, respectively. The number of surviving RGCs was determined by whole-mount retinas and frozen sections, while certain mRNA or protein was detected by q-PCR or ELISA, respectively.

RESULTS

The density (cell number/mm²) of RGCs was 410.77±56.70 in the retina 21d after optic nerve crush without any treatment, compared to 1351.39±195.97 in the normal control (P<0.05). RGCs in BMSCs treated eyes was 625.07±89.64/mm², significantly higher than that of no or PBS treatment (P<0.05). While RGCs was even less in the retina with intravitreal injection of BIM (354.07+39.77) and GIM (326.67+33.37) than that without treatment (P<0.05). BMSCs injection improved the internal BDNF expression in retinas.

CONCLUSION

Optic nerve crush caused rust loss of RGCs and intravitreally transplanted BMSCs at some extent protected RGCs from death. The effect of BMSCs and level of BDNF in retinas are both related to BDNF and GDNF expression in BMSCs.

Critical Role of the CXCL10/C-X-C Chemokine Receptor 3 Axis in Promoting Leukocyte Recruitment and Neuronal Injury during Traumatic Optic Neuropathy Induced by Optic Nerve Crush

Traumatic optic neuropathy (TON) is an acute injury of the optic nerve secondary to trauma. Loss of retinal ganglion cells (RGCs) is a key pathological process in TON, yet mechanisms responsible for RGC death remain unclear. In a mouse model of TON, real-time noninvasive imaging revealed a dramatic increase in leukocyte rolling and adhesion in veins near the optic nerve (ON) head at 9 hours after ON injury. Although RGC dysfunction and loss were not detected at 24 hours after injury, massive leukocyte infiltration was observed in the superficial retina. These cells were identified as T cells, microglia/monocytes, and neutrophils but not B cells. CXCL10 is a chemokine that recruits leukocytes after binding to its receptor C-X-C chemokine receptor (CXCR) 3. The levels of CXCL10 and CXCR3 were markedly elevated in TON, and up-regulation of CXCL10 was mediated by STAT1/3. Deleting CXCR3 in leukocytes significantly reduced leukocyte recruitment, and prevented RGC death at 7 days after ON injury. Treatment with CXCR3 antagonist attenuated TON-induced RGC dysfunction and cell loss. In vitro co-culture of primary RGCs with leukocytes resulted in increased RGC apoptosis, which was exaggerated in the presence of CXCL10. These results indicate that leukocyte recruitment in retinal vessels near the ON head is an early event in TON and the CXCL10/CXCR3 axis has a critical role in recruiting leukocytes and inducing RGC death.

The cataract situation in Suriname: an effective intervention programme to increase the cataract surgical rate in a developing country

AIMS

To provide an overview of cataract data in Suriname and to describe and evaluate a programme to control cataract blindness in a developing country.

DESIGN

Evaluation of hospital data and findings from a population-based cross-sectional survey.

METHODS

The implementation of a new cataract surgical intervention programme was described and retrospectively evaluated by analysing the number of cataract operations and other related indicators at the Suriname Eye Centre (SEC) in the period 2006-2014. Findings of the recent Rapid Assessment of Avoidable Blindness (2013-2014) survey were used to evaluate the national cataract situation in Suriname in people aged ≥50 years (n=2998), including prevalence of cataract blindness, outcome and cataract surgical rate (CSR).

RESULTS

Since the implementation of a new cataract intervention programme, the number of cataract operations at the SEC has increased from 1150 in 2006 to 4538 in 2014, leading to an estimated national CSR of 9103 per one million inhabitants. The prevalence of bilateral cataract blindness in Suriname was 0.8% (95% CI 0.2% to 1.3%) in individuals aged ≥50 years. The proportion of eyes with a postoperative visual acuity <6/60 (poor outcome) was lowest in eyes operated at the SEC (8.5%) and highest in surgeries performed by foreign humanitarian ophthalmic missions.

CONCLUSIONS

The cataract situation in Suriname is well under control since the implementation of the new intervention programme. Important factors contributing to this success were the introduction of phacoemulsification, intensive training, and improvement in the affordability and accessibility of cataract surgery. The proportion of poor outcomes was still >5%.

Macular pigment optical density: repeatability, intereye correlation, and effect of ocular dominance

Purpose

To evaluate short-term repeatability, intereye correlation, and effect of ocular dominance on macular pigment optical density (MPOD) measurements obtained using the QuantifEye Heterochromatic Flicker Photometer.

Patients and methods

A total of 72 study participants were enrolled in this prospective, cross-sectional study. Participants underwent a comprehensive ocular evaluation, including visual acuity, evaluation of ocular dominance, slit lamp examination, intraocular pressure measurement, and optic nerve head and macula analysis using optical coherence tomography and fundus photography. All study participants after initial training underwent MPOD measurement twice in both eyes in a randomized sequence. The repeatability was tested using Altman and Bland plots for first measurements with the second measurements for right eye and left eye and additionally by grouping eyes as a function of ocular dominance. The Pearson correlation coefficient was performed to assess the intereye correlation of MPOD values.

Results

The mean age of study participants was 35.5 years (range 22–68 years). The mean MPOD measurements for OD (right eye) and OS (left eye) were 0.47 and 0.48, respectively, which followed a normal distribution (Shapiro–Wilk test, P=0.6 and 0.2). The 95% limits of agreement of Altman and Bland plots for the first and second measurements were −0.12 to +0.11 and −0.13 to +0.12 for OD and OS, respectively. The correlation coefficient of mean MPOD measurements of OD and OS was r statistic =0.94 (Pearson correlation coefficient P<0.0001; r² 0.89). The 95% limits of agreement of Altman and Bland plots when evaluated by laterality of eye or by ocular dominance were narrow, with limits of agreement ranging from −0.13 to +0.12.

Conclusion

The MPOD measurements obtained using the QuantifEye show good short-term repeatability. There is excellent intereye correlation, indicating that the MPOD values of one eye data can predict the fellow eye value with 89% accuracy. The ocular dominance had no bearing on the outcome of this psychophysical test in ocular healthy eyes.

Epidemiology and aetiology of childhood ocular trauma in the Republic of Suriname

PURPOSE

To describe the epidemiology and aetiology of ocular trauma in school-aged children who previously visited the Suriname Eye Centre (SEC) of the Academic Hospital Paramaribo.

METHODS

In a hospital-based retrospective study, all cases of children who were school aged (8-15 years) at the time of the survey and previously underwent evaluation and/or treatment at the SEC because of ocular trauma were analysed. Demographic and ophthalmologic data were taken out of patient records; eye injuries were classified using the Birmingham Eye Trauma Terminology classification system. Main outcome measures were type of injury, mechanism/cause of injury, final visual acuity (VA), hospitalization, patient delay and patient compliance.

RESULTS

Five hundred and thirty-eight records were analysed which included 35 open globe injuries (OGI) (7%), 458 closed globe injuries (85%), five orbital fractures (1%) and 40 eyelid injuries (7%). The most frequent causes of trauma represented body parts (18%) and sticks or branches (13%) and resulted from poking (20%) or punching (13%) the eye. Final VA < 6/60 was reported in 58% of registered OGI. Where living in rural areas (p = 0.007), OGI (p < 0.0001) and poor compliance to scheduled check-ups (p < 0.0001) were statistically significantly related to an unfavourable outcome, patient delay was not. Patients having OGI were more often hospitalized than children with other injuries (p < 0.0001).

CONCLUSION

This is the first study providing data on childhood ocular trauma in Suriname. As the majority of childhood injuries were avoidable, new policies should aim at developing effective, targeted preventive strategies to promote awareness, parental supervision, immediate action and compliance.

Prevalence and Causes of Visual Impairment and Blindness in Central Iran; The Yazd Eye Study

PURPOSE

To determine the prevalence and causes of blindness and visual impairment (VI) in Yazd, central Iran.

METHODS

This population-based, cross-sectional study was performed on adults aged 40-80 years, residing in Yazd district, in 2010-2011. Eligible subjects were selected using cluster random sampling. Each participant underwent an interview and complete ophthalmologic examination. Blindness and VI were defined as best-corrected visual acuity (VA) <3/60 and < 6/18 in the better eye, respectively.

RESULTS

Out of 2,320 eligible individuals, 2,098 participated in the study (90.4% response rate), of whom, 2,023 subjects completed all evaluations. The standardized prevalence of blindness and VI were 0.7% (95% confidence interval [CI], 0.3-1.0%) and 4.4% (95% CI, 3.3-5.4%), respectively which was significantly associated with older age (odd ratio [OR] = 3.2, 95% CI: 1.9-5.2 and OR = 3.1, 95% CI: 2.3-4.2, respectively) and female sex (OR = 3.6, 95% CI: 1.1-12.3 and OR = 1.7, 95% CI: 1.2-2.5, respectively). The proportion of avoidable causes of blindness and VI were 92.9% (95% CI: 80.0-100.0%) and 76.6% (95% CI: 69.2-85.0%), respectively. Major causes of blindness were diabetic retinopathy (50.0%), glaucoma (21.4%) and cataracts (14.3%) whereas main causes of VI were cataracts (41.5%), diabetic retinopathy (17.0%) and age-related macular degeneration (13.8%).

CONCLUSIONS

Diabetic retinopathy, glaucoma, cataract and age-related macular degeneration were the leading causes of blindness and VI in Yazd, most of which are avoidable. Planning for prevention of blindness is highly recommended to decrease the proportion of avoidable blindness.

A Brazilian report using serological and molecular diagnosis to monitoring acute ocular toxoplasmosis

Background

Toxoplasmosis was recently included as a neglected disease by the Center for Disease Control. Ocular toxoplasmosis is one clinical presentation of congenital or acquired infection. The laboratory diagnosis is being used worldwide to support the clinical diagnosis and imaging. The aim of this study was to evaluate the use of serology and molecular methods to monitor acute OT in immunocompetent patients during treatment.

Methods

Five immunocompetent patients were clinically diagnosed with acute OT. The clinical evaluation was performed by ophthalmologic examination using the Early Treatment Diabetic Retinopathy Study, best-corrected visual acuity, slit lamp biomicroscopy, fundoscopic examination with indirect binocular ophthalmoscopy color fundus photography, fluorescein angiography and spectral optical coherence tomography (OCT). Serology were performed by ELISA (IgA, IgM, IgG) and confirmed by ELFA (IgG, IgM). Molecular diagnoses were performed in peripheral blood by cPCR using the Toxoplasma gondiiB1 gene as the marker. Follow-up exams were performed on day +15 and day +45.

Results

Only five non-immunocompromised male patients completed the follow up and their data were used for analysis. The mean age was 41.2 ± 11.3 years (median: 35; range 31–54 years). All of them were positive for IgG antibodies but with different profiles for IgM and IgA, as well as PCR. For all patients the OCT exam showed active lesions with the inner retinal layers being abnormally hyper-reflective with full-thickness disorganization of the retinal reflective layers, which assumed a blurred reflective appearance and the retina was thickened.

Conclusions

The presence of IgA and IgM confirmed the acute infection and thus was in agreement with the clinical evaluation. Our results show the adopted treatment modified the serological profile of IgM antibodies and the PCR results, but not the IgG and IgA antibodies and that imaging is a good tool to follow-up patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-015-1650-6) contains supplementary material, which is available to authorized users.

Prematurity and Low Birth Weight did not Correlate with Anti-Toxoplasma gondii Maternal Serum Profiles--a Brazilian Report

Gestational Toxoplasma gondii infection is considered a major risk factor for miscarriage, prematurity and low birth weight in animals. However, studies focusing on this topic in humans are scarce. The objective of this study is to determine whether anti-Toxoplasma gondii maternal serum profiles correlate prematurity and low birth weight in humans. The study examined 213 pregnant women seen at the High-Risk Pregnancy Hospital de Base, São José do Rio Preto, São Paulo, Brazil. All serological profiles (IgM-/IgG+; IgM-/IgG-; IgM+/IgG+) were determined by ELISA commercial kits. Maternal age, gestational age and weight of the newborn at birth were collected and recorded in the Statement of Live Birth. Prematurity was defined as gestational age <37 weeks and low birth weight ≤ 2499 grams. The t-test was used to compare values (p < 0.05). The mean maternal age was 27.6±6.6 years. Overall, 56.3% (120/213) of the women studied were IgM-/IgG+, 36.2% (77/213) were IgM-/IgG- and 7.5% (16/213) were IgM+/IgG+. The average age of the women with serological profile IgM+/IgG+ (22.3±3.9 years) was different from women with the profile IgM-/IgG+ (27.9±6.7 years, p = 0.0011) and IgM-/IgG- (27.9±6.4 years, p = 0.0012). There was no statistically significant difference between the different serological profiles in relation to prematurity (p = 0.6742) and low birth weight (p = 0.7186). The results showed that prematurity and low birth weight did not correlate with anti-Toxoplasma gondii maternal serum profiles.

Causes of visual impairment in children seen at a university-based hospital low vision service in Brazil

PURPOSE

To evaluate the epidemiologic characteristics of patients 0-7 years of age with visual impairment registered at a university hospital low vision service in Brazil.

METHODS

The medical records of visually impaired patients were retrospectively reviewed for sociodemographic characteristics and ocular and associated deficiencies. In addition to biographical information, the following data were collected: ocular disorders, diagnosis, affected anatomic region, etiology, and avoidable or unavoidable causes.

RESULTS

A total of 229 patients were included, 65% of whom were referred from rural health centers. The mean age at first appointment was 39.4 months. Associated nonophthalmic disorders were present in 47% of patients. The most prevalent disorders were congenital cataract (14%), toxoplasmosis (14%), and congenital glaucoma (13%). The most commonly affected anatomic regions were the retina (18%) and lens (15%); 33% had a normal-appearing globe. Using World Health Organization classifications, the most prevalent underlying etiologies were undetermined (43%), perinatal/neonatal factors (22%), and intrauterine factors (20%). Avoidable causes were found in 64% of the children.

CONCLUSIONS

The three leading causes of infant blindness in our patient cohort were congenital cataract, toxoplasmosis, and congenital glaucoma. The most commonly affected anatomic regions were retina, lens, and normal-appearing globe. The percentage of avoidable causes of impairment was high and the mean age at first appointment was late.

Benefits and risks of immediately sequential bilateral cataract surgery: a literature review

Immediately sequential bilateral cataract surgery (ISBCS) is a highly contended issue in ophthalmology, mainly due to the risk of bilateral endophthalmitis and financial penalties that many ophthalmologists face when performing simultaneous cataract surgeries. The purpose of this review is to understand the current status of the knowledge of ISBCS, mainly its benefits and risks and how they compare with the standard of care, delayed sequential bilateral cataract surgery. Evidence, although limited, increasingly supports ISBCS for providing faster rehabilitation, improved visual outcomes, and cost and time savings. Evidence does not support the fear of bilateral endophthalmitis resulting from the simultaneous procedure. However, stronger and greater evidence is needed before ISBCSs can be considered the standard of care. Where ISBCS can potentially create the most beneficial impact is in public eye health programmes in developing countries, but this has not yet been explored.

Current state of therapeutic strategies with ranibizumab in neovascular age-related macular degeneration

PURPOSE OF REVIEW

To summarize the current dosing strategies in the management of neovascular age-related macular degeneration with intravitreal injections of ranibizumab.

RECENT FINDINGS

A variety of therapeutic strategies has been recently described as an alternative to the monthly fixed treatment. The efficacy and local and systemic safety results of each approach is relevant in order to make a clinical decision and to provide patients an accurate information.

SUMMARY

The proposed therapeutic strategies achieve positive visual outcomes when compared with monthly fixed regimen in the clinical trials. However, the real-life practice does not reflect these results. The main cause of this difference is the incapability to adopt any of the different strategies as the clinics are completely booked and this turns into a delay in the diagnostic and treatment visits.

Blindness Registers as Epidemiological Tools for Public Health Planning: A Case Study in Belize

For public eye health programs, blindness registers can be an important tool for informing service planning. This study examines how the Belize Council for the Visually Impaired (BCVI) used its blindness register data to drive several public health interventions. Cross-sectional analysis was performed for all active registrants (n=1194) to determine the distribution of causes of registration according to age, sex, and geographical district. Cataract was the leading cause of registration (39.6%), followed by glaucoma (20.8%), diabetic retinopathy (10.2%), and childhood blindness (9.4%). The distribution of the causes of registration was fairly similar between men and women and across the various districts. However, in Stann Creek, whose population is largely of African descent, glaucoma exceeded cataract. For most causes, the majority of registrants were registered at age 50 or older. Follow-up was conducted four years later. Several interventions had been initiated, most notably bolstering cataract surgical services and creating screening programs for glaucoma and diabetic retinopathy. The register itself was also improved to maximize its utility for future use. While standardized surveys may be the most appropriate method of estimating population-based measures such as prevalence or incidence, the blindness register is still a valuable source of data for public health planning.