Challenges of ophthalmic care in the developing world

Infectious eye disease in the 21st century-an overview

Infectious diseases affecting the eye often cause unilateral or asymmetric visual loss in children and people of working age. This group of conditions includes viral, bacterial, fungal and parasitic diseases, both common and rare presentations which, in aggregate, may account for a significant portion of the global visual burden. Diagnosis is frequently challenging even in specialist centres, and many disease presentations are highly regional. In an age of globalisation, an understanding of the various modes of transmission and the geographic distribution of infections can be instructive to clinicians. The impact of eye infections on global disability is currently not sufficiently captured in global prevalence studies on visual impairment and blindness, which focus on bilateral disease in the over-50s. Moreover, in many cases it is hard to differentiate between infectious and immune-mediated diseases. Since infectious eye diseases can be preventable and frequently affect younger people, we argue that in future prevalence studies they should be considered as a separate category, including estimates of disability-adjusted life years (DALY) as a measure of overall disease burden. Numbers of ocular infections are uniquely affected by outbreaks as well as endemic transmission, and their control frequently relies on collaborative partnerships that go well beyond the remit of ophthalmology, encompassing domains as various as vaccination, antibiotic development, individual healthcare, vector control, mass drug administration, food supplementation, environmental and food hygiene, epidemiological mapping, and many more. Moreover, the anticipated impacts of global warming, conflict, food poverty, urbanisation and environmental degradation are likely to magnify their importance. While remote telemedicine can be a useful aide in the diagnosis of these conditions in resource-poor areas, enhanced global reporting networks and artificial intelligence systems may ultimately be required for disease surveillance and monitoring.

Assessing spectral effectiveness in color fundus photography for deep learning classification of retinopathy of prematurity

Significance

Retinopathy of prematurity (ROP) poses a significant global threat to childhood vision, necessitating effective screening strategies. This study addresses the impact of color channels in fundus imaging on ROP diagnosis, emphasizing the efficacy and safety of utilizing longer wavelengths, such as red or green for enhanced depth information and improved diagnostic capabilities.

Aim

This study aims to assess the spectral effectiveness in color fundus photography for the deep learning classification of ROP.

Approach

A convolutional neural network end-to-end classifier was utilized for deep learning classification of normal, stage 1, stage 2, and stage 3 ROP fundus images. The classification performances with individual-color-channel inputs, i.e., red, green, and blue, and multi-color-channel fusion architectures, including early-fusion, intermediate-fusion, and late-fusion, were quantitatively compared.

Results

For individual-color-channel inputs, similar performance was observed for green channel (88.00% accuracy, 76.00% sensitivity, and 92.00% specificity) and red channel (87.25% accuracy, 74.50% sensitivity, and 91.50% specificity), which is substantially outperforming the blue channel (78.25% accuracy, 56.50% sensitivity, and 85.50% specificity). For multi-color-channel fusion options, the early-fusion and intermediate-fusion architecture showed almost the same performance when compared to the green/red channel input, and they outperformed the late-fusion architecture.

Conclusions

This study reveals that the classification of ROP stages can be effectively achieved using either the green or red image alone. This finding enables the exclusion of blue images, acknowledged for their increased susceptibility to light toxicity.

Preventing the Argentinian flag sign and managing anterior capsular tears: A review

The Argentinian flag sign (AFS) is a feared complication during cataract extraction. Intralenticular pressures, especially excessive posterior pressure, have been identified as potential mechanisms for capsular stress and tearing associated with AFS. Capsular tension is created by positive intralenticular pressures, which cause the irido-lens diaphragm to move anteriorly once the manual capsulorhexis has been initiated. This tension can cause inadvertent tears that self-propagate to the lens equator, causing an AFS, among other intraoperative complications. Thus, this review highlights the importance of identifying intumescent cataracts as well as a combination of techniques to relieve intracapsular pressures needed to prevent AFS. However, some instances of anterior capsular tears are unavoidable. Therefore, focus will also be placed on techniques during cataract extraction used to manage anterior capsular tears, mitigating extension to the posterior capsule.

Visual stimulation in the neonatal intensive care unit: A systematic literature review

We aimed to systematically categorize evidence on the types of early visual stimulation applied to preterm infants (PTIs) admitted to neonatal intensive care units (NICUs), aiming to improve visual function parameters. This study was conducted according to PRISMA and registered in PROSPERO with CRD42022333753. Last search was conducted on March 15, 2023, in four different databases. Articles written in English, Portuguese, Spanish, or Italian, and available in full text were included. Two independent authors performed study selection, data extraction, and bias risk assessment. If there was any disagreement, a third author was contacted. A total of eight studies were included. From these, 62.5% presented a low risk of bias. 100% used a multisensory intervention, which included visual stimulation. In 50%, visual intervention consisted of black and white stimulation cards placed inside the incubator for three minutes. The outcomes showed positive benefits in visual function parameters and other reported clinical benefits in breastfeeding and neuromuscular development. This review demonstrated there is still scarce literature on the effects of early visual stimulation on purely visual functional outcomes, although the existing findings are promising. Parental involvement has been generating unquestionable benefits for the binomial mother-infant and gaining greater acceptance by health professionals.

A meta-analysis of adverse effects of retinopathy of prematurity on neurodevelopment in preterm infants

BACKGROUND

Retinopathy of prematurity (ROP) increases with the survival of late preterm infants, but its relationship with neurodevelopmental outcomes in preterm infants remains controversial. To investigate the relationship between ROP and its severity and adverse neurodevelopmental outcomes in preterm infants.

METHODS

We conducted a meta-analysis. All relevant literature before November 2022 were retrieved from PubMed, Embase, Cochrane Library Web of Science, CNKI, CBM, Wan fang Data, and VIP Database. According to the inclusion criteria and exclusion criteria, eligible literature were included to conduct clinical trial quality assessment, and the Newcastle-Ottawa scale was used to evaluate the quality of evidence. Meta-analysis was performed using RevMan5.3. Data extraction, quality assessment, and meta-analysis were performed independently by 2 people. Mean difference or standardized mean difference of motor, language and cognitive scores (Bayley III or Bayley II) were used as effect sizes for continuous data analysis, all of which were represented by 95% CI. For heterogeneity (I2 ≥ 50% or P < .10), a random effects model was used, otherwise a fixed effects model was used.

RESULTS

A total of 6 literature were included. The results of the ROP group for motor (comprehensive motor, proportional motor, and fine motor), language and cognitive scores were -5.57 (95%CI, -1.43 to 0.04), -0.95 (95%CI, 1.4-0.50), -1.34 (95% CI, 1.77-0.92), -1.75 (95% CI, 2.26-1.24) and -5.56 (95% CI, 9.56-1.57). Additionally, the results of severe ROP group for motor (comprehensive motor, proportional motor, fine motor), language and cognitive scores were -8.32 (95%CI, -8.91 to 7.74), -1.10 (95%CI, -1.83 to -0.36), -1.08 (95%CI, -1.75 to -0.41), -7.03 (95%CI, -7.71 to 6.35), and -7.96 (95%CI, -8.5 to -7.42).

CONCLUSIONS

The Bayley Scale scores of the ROP group were lower than those of the not ROP group, and the scores of the severe ROP were significantly lower than those of the not severe ROP group. These findings suggest that ROP can indeed delay motor, language and cognitive, especially in severe cases.

A Multicenter Cross-Sectional Study of the Awareness and Screening for Retinopathy of Prematurity Among NICU Pediatricians in Makkah and Jeddah, Saudi Arabia

Purpose This study aims to evaluate neonatal intensive care unit (NICU) pediatricians' knowledge about retinopathy of prematurity (ROP) in the major tertiary centers in Makkah and Jeddah, Saudi Arabia. Methods This cross-sectional study uses a self-administered electronic questionnaire completed by NICU pediatricians at the main hospitals of Makkah and Jeddah cities. Based on the participants' correctly selected responses to the validated questionnaire, a scoring system was used in the data analysis to show their level of ROP knowledge. Results Seventy-seven responses were analyzed. The male gender was 49.4%. The majority were recruited from the ministry of health hospitals (63.6%). A small proportion (28.6%) correctly identified who performs the examination. Around three-quarters of the participants have correctly stated that ROP therapy is a very good option to prevent blindness (72.7%). The treatment should generally begin within 72 hours after diagnosis of sight-threatening ROP (79.2%). The requirements for ROP screening were unknown to more than half of our participants (53.2%). With the lowest score of 4.0 and a maximum score of 17.0, the median knowledge score was 13.0 (IQR = 11.0 to 14.0). Based on pediatricians' clinical qualifications, knowledge scores varied significantly. Residents had a significantly lower knowledge score than specialists and consultants (median = 7.0, IQR = 6.0 to 9.0, p = 0.001). Additionally, pediatricians with less experience (<5 years) performed significantly lower on the knowledge score (median = 10.0, IQR = 6.2 to 12.8) than those with more experience (median = 13.0, IQR = 11.0 to 15.0) for participants with 5-10 years of experience, and (median = 13.0, IQR = 11.0 to 14.0) for participants with >10 years of experience). Conclusion Our study showed that NICU pediatricians understood ROP risk factors and treatment options. Nevertheless, they needed to understand the ROP screening inclusion criteria and when the screening could be stopped. Residents scored substantially lower in knowledge overall. Accordingly, we emphasized the need for NICU pediatricians to increase their level of awareness by having regular educational sessions and standardizing one guideline to be strictly followed.

Pulmonary function in school-age children following intravitreal injection of bevacizumab for retinopathy of prematurity

The effect of anti-vascular endothelial growth factor on neonatal lung development was inconclusive. To evaluate pulmonary function in school-age children who have received intravitreal bevacizumab (IVB) for retinopathy of prematurity (ROP), this study included 118 school-aged children who were grouped into three groups: full-term control children (group 1), preterm children who had not received IVB treatment (group 2) and preterm children with ROP who had received IVB treatment (group 3). Pulmonary function was measured by spirometry and impulse oscillometry. Pulmonary function was significantly better in group 1 than in groups 2 and 3 (all p < 0.05 in forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁), forced expiratory flow between 25 and 75% of FVC (FEF_25-75), and respiratory resistance at 5 Hz and difference between respiratory resistance at 5 and 20 Hz (R5-R20). There were no statistically significant differences between group 2 and group 3 in all pulmonary function parameters, including FVC, FEV₁, ratio of FEV₁ to FVC, FEF_25-75, R5, R20, R5-R20, and respiratory reactance at 5 Hz. In conclusion, our study revealed that preterm infants receiving IVB for ROP had comparable pulmonary function at school age to their preterm peers who had not received IVB treatment.

Correlation between apelin and VEGF levels in retinopathy of prematurity: a matched case-control study

Background

Although several clinical studies have analysed the relationship between the levels of vascular endothelial growth factor (VEGF) and apelin-13 in venous blood and retinopathy of prematurity (ROP), no definitive conclusions have been reached. This study aimed to investigate the relationship between apelin-13 levels and VEGF levels and ROP.

Methods

Differences in plasma apelin-13 and VEGF levels were analysed in two groups of infants born with birth weight < 1500 g and gestational age < 32 weeks at Peking University People’ s Hospital. One group comprised infants diagnosed with ROP and the other group was a control group comprising infants without ROP.

Results

Apelin-13 levels were significantly lower in the ROP group than in the control group, while VEGF levels showed the opposite result (both P < 0.001). Infants with severe ROP had lower apelin-13 levels and higher VEGF levels than with mild ROP (both P < 0.05).The receiver operating characteristic curve for apelin-13 level as the indicator of ROP showed that a cut-off value of 119.6 pg/mL yielded a sensitivity of 84.8% and a specificity of 63.6%, while for VEGF level, the cut-off value of 84.3 pg/mL exhibited a sensitivity of 84.8% and a specificity of 66.7%.

Conclusions

Plasma apelin-13 and VEGF levels at 4–6 weeks of age may play a role in assisting the diagnosis of ROP.

Virtual Reality and Augmented Reality- Emerging Screening and Diagnostic Techniques in Ophthalmology: a Systematic Review

In healthcare, virtual reality (VR) and augmented reality (AR) have been applied extensively for many purposes. Similar to other technologies such as telemedicine and artificial intelligence, VR and AR may improve clinical diagnosis and screening services in ophthalmology by alleviating current problems, including workforce shortage, diagnostic error, and underdiagnosis. In the past decade a number of studies and products have used VR and AR concepts to build clinical tests for ophthalmology, but comprehensive reviews on these studies are limited. Therefore, we conducted a systematic review on the use of VR and AR as a diagnostic and screening tool in ophthalmology. We identified 26 studies that implemented a variety of VR and AR tests on different conditions, including VR cover tests for binocular vision disorder, VR perimetry for glaucoma, and AR slit lamp biomicroscopy for retinal diseases. In general, while VR and AR tools can become standardized, automated, and cost-effective tests with good user experience, several weaknesses, including unsatisfactory accuracy, weak validation, and hardware limitations, have prevented these VR and AR tools from having wider clinical application. Also, a comparison between VR and AR is made to explain why studies have predominantly used VR rather than AR.

Stem cells in neonatal diseases: An overview

Preterm birth and its common complications are major causes of infant mortality and long-term morbidity. Despite great advances in understanding the pathogenesis of neonatal diseases and improvements in neonatal intensive care, effective therapies for the prevention or treatment for these conditions are still lacking. Stem cell (SC) therapy is rapidly emerging as a novel therapeutic tool for several diseases of the newborn with encouraging pre-clinical results that hold promise for translation to the bedside. The utility of different types of SCs in neonatal diseases is being explored. SC therapeutic efficacy is closely associated with its secretome-conditioned media and SC-derived extracellular vesicles, and a subsequent paracrine action in response to tissue injuries. In the current review, we summarize the pre-clinical and clinical studies of SCs and its secretome in diverse preterm and term birth-related diseases, thereby providing new insights for future therapies in neonatal medicine.

A Hydrogel Ionic Circuit Based High-Intensity Iontophoresis Device for Intraocular Macromolecule and Nanoparticle Delivery

Iontophoresis is an electrical-current-based, noninvasive drug-delivery technology, which is particularly suitable for intraocular drug delivery. Current ocular iontophoresis devices use low current intensities that significantly limit macromolecule and nanoparticle (NP) delivery efficiency. Increasing current intensity leads to ocular tissue damage. Here, an iontophoresis device based on a hydrogel ionic circuit (HIC), for high-efficiency intraocular macromolecule and NP delivery, is described. The HIC-based device is capable of minimizing Joule heating, effectively buffering electrochemical (EC) reaction-generated pH changes, and absorbing electrode overpotential-induced heating. As a result, the device allows safe application of high current intensities (up to 87 mA cm-2 , more than 10 times higher than current ocular iontophoresis devices) to the eye with minimal ocular cell death and tissue damage. The high-intensity iontophoresis significantly enhances macromolecule and NP delivery to both the anterior and posterior segments by up to 300 times compared to the conventional iontophoresis. Therapeutically effective concentrations of bevacizumab and dexamethasone are delivered to target tissue compartments within 10-20 min of iontophoresis application. This study highlights the significant safety enhancement enabled by an HIC-based device design and the potential of the device to deliver therapeutic doses of macromolecule and NP ophthalmic drugs within a clinically relevant time frame.

The adoption of deep learning interpretability techniques on diabetic retinopathy analysis: a review

Diabetic retinopathy (DR) is a chronic eye condition that is rapidly growing due to the prevalence of diabetes. There are challenges such as the dearth of ophthalmologists, healthcare resources, and facilities that are unable to provide patients with appropriate eye screening services. As a result, deep learning (DL) has the potential to play a critical role as a powerful automated diagnostic tool in the field of ophthalmology, particularly in the early detection of DR when compared to traditional detection techniques. The DL models are known as black boxes, despite the fact that they are widely adopted. They make no attempt to explain how the model learns representations or why it makes a particular prediction. Due to the black box design architecture, DL methods make it difficult for intended end-users like ophthalmologists to grasp how the models function, preventing model acceptance for clinical usage. Recently, several studies on the interpretability of DL methods used in DR-related tasks such as DR classification and segmentation have been published. The goal of this paper is to provide a detailed overview of interpretability strategies used in DR-related tasks. This paper also includes the authors' insights and future directions in the field of DR to help the research community overcome research problems.

Evaluation of a low-resource screening strategy for ophthalmic pathologies and associated neurological morbidity in an older Tanzanian HIV-positive population

Globally, 43 million people are living with HIV, 90% in developing countries. Increasing life expectancy with combination antiretroviral therapy (cART) results in chronic complications, including HIV-associated neurocognitive disorders (HAND) and eye diseases. HAND screening is currently challenging. Our aim was to evaluate clinical utility of retinopathy as a screening measure of HAND in older cART-treated individuals in Tanzania and feasibility of smartphone-based retinal screening in this low-resource setting. A cross-sectional systematic sample aged ≥ 50-years attending routine HIV follow-up in Tanzania were comprehensively assessed for HAND by American Academy of Neurology criteria and received ophthalmic assessment including smartphone-based retinal imaging. HAND and ophthalmic assessments were independent and blinded. Diagnostic accuracy was evaluated by AUROC curves. Of 129 individuals assessed, 69.8% were visually impaired. Thirteen had retinopathy. HAND prevalence was 66.7%. Retinopathy was significantly associated with HAND but HIV-disease factors (CD4, viral load) were not. Diagnostic accuracy of retinopathy for HAND was poor (AUROC 0.545-0.617) but specificity and positive predictive value were high. We conclude that ocular pathology and HAND appear highly prevalent in this low-resource setting. Although retinal screening cannot be used alone identify HAND, prioritization of individuals with abnormal retinal screening is a potential strategy in low-resource settings.

Retinopathy of Prematurity as Multidisciplinary Approach, a Pediatricians Standpoint, and Practice

Purpose

This study aims to measure the knowledge levels toward retinopathy of prematurity (ROP) among pediatricians covering neonatal intensive care units (NICUs) in the major hospitals in Tabuk, Saudi Arabia. To our knowledge, this is the first report to assess the awareness level of ROP in the NICU pediatricians in the region.

Patients and Methods

This is a quantitative, non-experimental, cross-sectional, descriptive study using self-administered electronic questionnaires to assess the knowledge level among NICU pediatricians at the main hospitals of Tabuk city. We used a self-administer online validated knowledge, attitude, and practice (KAP) questionnaire. A scoring system was implemented in the data analysis, depending on the correct chosen answers on the KAP questionnaire, to present the ROP knowledge level in the participants.

Results

The study included 41 NICU pediatricians. Most of the participants’ age exceeded 40 years (51.2%). The majority were recruited from either King Salman Military hospital (34.1%) or King Khalid hospital (31.7%). The average frequency of preterm infants seen per month exceeded 15 infants among 41.4% of the respondents. Most pediatricians recognized the important treatment modalities available for ROP (92.7%); however, only 24.4% of them could recognize that 32 weeks or less is the gestational age of the screening criteria for ROP. The overall knowledge score ranged between 4 and 10, out of a possible maximum of 12 with a mean ± SD of (6.68±1.47). The majority (75.6%) believe that the ROP treatment can successfully prevent blindness.

Conclusion

Our study demonstrated that the NICU pediatricians have good knowledge about the treatment modalities of ROP. However, their knowledge about the inclusion criteria of ROP screening was insufficient. Thus, we highlighted the necessity of raising the awareness level and the strict application of the clinical guidelines among NICU pediatricians and healthcare workers involved in managing ROP.

Case Report: Glaucoma in an Infant With Retinopathy of Prematurity

Retinopathy of prematurity (ROP) is a leading cause of childhood blindness that occurs due to incomplete development of retinal blood vessels in preterm infants. Glaucoma is an ocular comorbidity in some patients with ROP, and it may be associated with immature anterior chamber development, ROP itself, or the treatment for ROP. There have been a few reports of narrow-angle glaucoma after laser treatment for ROP. In this case report, we describe the course of a female infant born at 24 weeks and 5 days of gestational age with treatment-requiring ROP treated with laser photocoagulation who subsequently developed very elevated intraocular pressure and shallow anterior chambers without pupillary block. The patient required bilateral ab externo trabeculotomy for elevated intraocular pressure, which normalized after the procedure. The patient has remained stable at the last follow-up at 51 weeks postmenstrual age. Differing from previous glaucoma presentations in this setting, we illustrate a case of elevated intraocular pressure and anterior chamber narrowing after laser therapy without pupillary block or synechiae. The possible multifactorial etiology of glaucoma in this patient, including incomplete angle development, ischemia, and laser treatment, highlight the need for glaucoma screening in patients with ROP, both in the short and long term.

GEOGRAPHIC ACCESS DISPARITIES TO CLINICAL TRIALS IN RETINOPATHY OF PREMATURITY IN THE UNITED STATES

BACKGROUND/PURPOSE

To identify geographic and socioeconomic variables predictive of residential proximity to retinopathy of prematurity (ROP) clinical trial locations.

METHODS

This cross-sectional epidemiological study used census tract-level data from three national public data sets and trial-level data from ClinicalTrials.gov. Socioeconomic predictors of driving distance and time to the nearest ROP clinical trial location were identified. Primary outcomes were time >60 minutes and distance >60 miles traveled to the nearest ROP clinical trial site.

RESULTS

Multivariate analysis showed that residents were more likely to travel >60 minutes to the nearest ROP clinical trial site if they lived in census tracts that were rural (adjusted odds ratio 1.20, P = 0.0002), had higher percentages of the population living ≤ federal poverty level (fourth quartile vs. first quartile, adjusted odds ratio 1.19, P < 0.0001), or had less education (associate vs. bachelor's degree, adjusted odds ratio 1.01, P <0.007). By contrast, counties with higher percentages of births with birth weight <1500 g (adjusted odds ratio 0.88, P = 0.0062) were less likely to travel >60 minutes. Similar variables predicted travel distance.

CONCLUSION

Although counties with higher incidences of very low-birth-weight infants were closer to ROP clinical trial sites, residents living in rural and low-income census tracts had significantly greater travel burdens.

Cataract surgery risk stratification in phacoemulsification and manual small incision cataract surgery in a teaching hospital

PURPOSE

To evaluate a system that objectively assesses the risk of cataract surgery complications performed with phacoemulsification and manual small incision cataract surgery (MSICS) techniques.

METHODS

The study was a retrospective comparative interventional case series. Electronic medical records of consecutive eyes that underwent cataract surgery from January 2019 to December 2019 were evaluated. Patient's demographic data and preoperative risk factors were identified, and cataract was categorized as per Lens Opacities Classification System (III). Cataract eyes were grouped into normal cataract cases (G1) and complex cataract cases (G2 and G3), based on the risk factors. The rate of complications in each group and the rate of each complication were calculated and compared.

RESULTS

The overall rate of anyone complication was 2.2% with 2.3% in G1, 1.0% in G2 and 3.9% in G3 (p < 0.001). MSICS technique, mostly used for complex cases (54.2%), reported a higher complication rate than the phacoemulsification technique (2.9% vs 1.4%, p < 0.001). However, the complication rates among the normal and complex cases were similar (2.3% vs 2.2%, p = 0.376). The total posterior capsular tear rate was 1.1% with no vitreous loss in nearly 1 in eight eyes.

CONCLUSION

A preoperative risk stratification system is crucial for obtaining informed consent and better allocation of cases to surgeons based on their expertise to minimize intraoperative complications.

Macular Structure and Microvasculature Changes in AIDS-Related Cytomegalovirus Retinitis Using Optical Coherence Tomography Angiography

Background: Cytomegalovirus retinitis (CMVR) is a crucial blind-causing disease of AIDS-related ocular opportunistic infection. The CMVR lesions produced retinal necrosis. It is not entirely clear whether CMVR eyes without macular-involved necrotic lesions may have subtle macular damage. In this study, we conducted a cross-sectional study using optical coherence tomography angiography (OCTA) to evaluate macular microvasculature and structure in eyes with AIDS-related CMVR.

Methods: Acquired immune deficiency syndrome (AIDS)-related CMVR patients (active and inactive CMVR) and healthy controls treated in the Department of Ophthalmology, Beijing Youan Hospital, Capital Medical University between August 25, 2019, and October 18, 2019, were recruited. All OCTA parameters, including the foveal avascular zone (FAZ), retinal vessel density (VD), choroidal vascularity index (CVI), retinal thickness, and choroidal thickness, were compared between groups after the signal strength was corrected.

Results: Signal strength in the 3 × 3 and 6 × 6 mm scan patterns was significantly weaker in the inactive CMVR group than in the control group (both p < 0.001). After adjusting for signal strength, heterogeneity in the central fovea and parafoveal quadrants was present with a shift toward lower macular chorioretinal vasculature, decreased full choroidal thickness, and thicker retinal thickness in the active and inactive CMVR groups. The retinal nerve fiber layer (RNFL) and inner nuclear layer (INL) were significantly thicker in the active and inactive CMVR groups than in the control group (all p < 0.05). For photoreceptor-retinal pigment epithelium (PR-RPE) thickness, no significant differences were found in any quadrant between groups. Foveal avascular zone areas were not significantly different among the three groups (p = 0.053).

Conclusions: Subtle macular structure and microvasculature damage still existed in CMVR eyes without macular-involved necrotic lesions. The results of our study are helpful for a deep understanding of the damage caused by CMVR.

Frequency of retinopathy of prematurity (ROP) in infants screened for ROP: two years follow-up results of a single center in Turkey

AIM

The aim of this retrospective study was to determine the incidence of retinopathy of prematurity (ROP) in infants referred to our clinic for screening ROP.

MATERIAL AND METHOD

The data of 729 infants who were referred to the ROP outpatient clinic of the Ophthalmology Unit of Erzincan Binali Yildirim University, Turkey between April 2018 and March 2020 were analyzed retrospectively. The gestational age and weight of the infants, stay in the neonatal intensive care unit, duration of oxygen therapy, and detailed ophthalmologic examination findings were recorded in the study.

FINDINGS AND RESULTS

Of the 729 babies screened for ROP, 122 (16.7%) of them had ROP. Infants with gestational age of ≤28 weeks constitute 3.3% of all infants and ROP rate was significantly higher than infants with older gestational age (P < 0.001). There were 39 babies born under 1000 grams and ROP was present in 28 (71.8%) of these infants and the incidence of ROP was higher than infants with higher birth weight (P < 0.001). With the result of logistic regression analysis, gestational age (OR:0.592,95% CI:0.208-0.779,P < 0.001), stay in NICU (OR:0.998,95% CI:1.022-1.421,P = 0.001), and duration of oxygen (O₂) therapy (OR:34.309, 95% CI:2.043-28.235,P = 0.004) were detected the independent risk factors for ROP.

CONCLUSION

Although infants with ≤1000 grams gestational weight and ≤28 weeks gestational age are more likely to have ROP, it is clear that screening for all infants at risk, regardless of gestational weight and age, is very important in preventing ROP-related vision loss. In addition, it is also recommended to control the duration of staying in neonatal intensive care unit and oxygen therapy to as little as needed.

Cost-effectiveness of Descemet stripping automated endothelial keratoplasty versus penetrating keratoplasty in patients with endothelial dysfunction in India

Purpose:

The aim of this study was to compare the cost-effectiveness and perform cost-utility analysis of Descemet stripping automated endothelial keratoplasty (DSAEK) vs. penetrating keratoplasty (PK) in Indian population.

Methods:

This was an institutional, ambispective, observational study. Patients who underwent PK or DSAEK for endothelial dysfunction were included and followed up for 2 years; those with other ocular comorbidities were excluded. The analysis was performed from the patient’s perspective receiving subsidized treatment at a tertiary care hospital. Detailed history, ophthalmic examination, total expenditure by patient, and clinical outcomes were recorded. The main outcome measures were best spectacle-corrected visual acuity (BSCVA), graft survival (Kaplan–Meier survival estimates), incremental cost-effectiveness ratio (ICER), and incremental cost-utility ratio (ICUR). Utility values were based on quality-adjusted life years (QALYs) associated with visual acuity outcomes. Statistical analysis was performed using SPSS software package, version 12.1; a value of P < 0.05 was considered statistically significant.

Results:

A total of 120 patients (PK: 60, DSAEK: 60) were included. At 2 years, for a similar logMAR BSCVA, [PK (0.32 ± 0.02), DSAEK (0.25 ± 0.02); P = 0.078], the overall cost for PK (13511.1 ± 803.3 INR) was significantly more than DSAEK (11092.9 ± 492.1 INR) (difference = 1952.6 INR; P = 0.01). ICER of DSAEK relative to PK was –39,052 INR for improvement in 1 logMAR unit BSCVA. ICUR of DSAEK relative to PK was –1,95,260 INR for improvement in 1 QALY.

Conclusion:

DSAEK was more cost-effective than PK in patients with endothelial dysfunction at 2 years.

Early-term deliveries and long-term pediatric ophthalmic morbidity of the offspring. Int J Gynaecol Obstet 2021;157:640-646. [PMID: 34383310 DOI: 10.1002/ijgo.13875]

OBJECTIVE

To examine whether early-term delivery impacts on the long-term ophthalmic health of offspring.

METHODS

A retrospective population-based cohort study was conducted, including all singleton deliveries (1991-2014) occurring at a tertiary medical center. Gestational age was divided into: early prematurity, late prematurity, and early, full, late, and post term. Hospitalizations of offspring up to 18 years of age involving ophthalmic morbidity were evaluated. Survival curves compared cumulative hospitalizations and regression models controlled for confounders.

RESULTS

During the study period, 243 363 deliveries met the inclusion criteria. Ophthalmic-related hospitalization rates were lower among early-term born children (1.0%) as compared with early- (2.2%) and late-preterm (1.3%) born children, but higher than those in full- (0.9%), late- (0.8%), and post-term (0.8%) born offspring (P < 0.001). The survival curve demonstrated significantly different hospitalization rates in the different gestational ages (P < 0.001). The regression demonstrated an independent risk for ophthalmic morbidity among early-term born offspring (adjusted hazard ratio 1.14, confidence interval 1.03-1.27, P = 0.009), whereas late- and post-term deliveries were associated with a lower risk (adjusted hazard ratio 0.83 and 0.74, respectively) as compared with full-term deliveries.

CONCLUSION

The risk for long-term ophthalmic-related hospitalizations of offspring gradually declines as gestational age advances.

VEGF-mediated angiogenesis in retinopathy of prematurity is co-regulated by miR-17-5p and miR-20a-5p

The microRNAs miR-17-5p and miR-20a-5p play important roles on angiogenesis; however, it is arguable whether they regulate the formation of retinal blood vessels in retinopathy of prematurity (ROP). We used a mouse model of oxygen-induced retinopathy (OIR) to simulate the development of retinas in mice suffering from ROP, and the expression levels of miR-20a-5p, miR-17-5p, hypoxia-inducible factor 1-alpha (HIF-1α), and vascular endothelial growth factor (VEGF) were measured by RT-qPCR and Western blotting. Cell proliferation, apoptosis, and angiogenesis in the OIR model mice were measured using MTT assays, flow cytometry, and Matrigel assays, respectively. The interaction between HIF-1α/VEGF and miR-20a-5p/miR-17-5p were further validated using dual-luciferase reporter assays, biotin-labeled RNA-pulldown, and RNA immunoprecipitation (RIP) assays. In our OIR model, retinal angiogenesis in the mice was associated with down-regulation of miR-20a-5p and miR-17-5p, as well as up-regulation of HIF-1α and VEGF. In addition, the miR-20a-5p and miR-17-5p inhibited cell proliferation and angiogenesis through regulating HIF-1α and VEGF in the retinal cells of the OIR model mice. Moreover, it was found that miR-20a-5p and miR-17-5p bind to HIF-1α and VEGF at the 3'UTR, and there was a combined effect between miR-20a-5p and miR-17-5p on the regulation of HIF-1α and VEGF. It is worth noting that miR-17-5p and miR-20a-5p can preferentially regulate HIF-1α, then act on VEGF, thereby affecting the angiogenesis associated with ROP.

Distribution and determinants of hospital efficiency and relative productivity in county-level hospitals in rural China: an observational study

BACKGROUND

Cataract surgery is very important to prevent blindness, but its productivity and efficiency in China are unknown. Our study aimed to evaluate the geographical distribution of cataract surgeons and prospectively identify the factors associated with the increased productivity in cataract surgery and efficiency in outpatient ophthalmic services in rural Chinese hospitals.

METHODS

Data were prospectively collated from various hospital datasets and the census registered by the geographical unit county. Prior to mapping, the geographical location data of counties were cross-linked with the equivalent ophthalmologist and service output data to create categories and map multiple data attributes. Descriptive statistical analyses were performed to characterise the data stratified by county. Linear regression analyses were used to explore the factors associated with the increased productivity/efficiency.

RESULTS

The ophthalmologists, surgical productivity of ophthalmologists and outpatient efficacy of ophthalmologists significantly varied across counties. During the period between 2016 and 2018, the median (IQR) change in surgical productivity of and outpatient efficacy of ophthalmologists were 31.627 (-3.33 to 29.94) and 118.08 (-132.30 to 740.89). In the simple regression analysis for predictors of a high productivity change, only the increased number of phaco machine had statistical significance (p=0.003). In addition, only the gross domestic product per capita in 2016 was associated with an increased improvement in efficiency of outpatient services (p=0.008).

CONCLUSIONS

This study demonstrated that the ophthalmologist productivity and the efficiency of outpatient services were unequally geographically distributed, and their predictors were identified. Further studies to elucidate the extent of the problem and improve the health service delivery models are required.

Laser photocoagulation for the treatment of bilateral late-onset retinopathy of prematurity-related retinal detachment in an adult male: A case report

RATIONALE

Retinopathy of prematurity (ROP) is one of the major leading causes of childhood visual morbidity worldwide. Retinal break and traction develop in regressed ROP can further result in rhegmatogenous or tractional retinal detachment years or even decades later.

PATIENT CONCERNS

Here, we reported a case of bilateral ROP related late complication in a 36-year-old male with a chief complaint of increased floaters in his left eye.

DIAGNOSES

The fundus examination showed demarcation lines over temporal side in both eyes with tractional retinal detachment and retinal breaks anterior to the lines. A diagnosis of ROP-related late complication of combined tractional and rhegmatogenous retinal detachment was made.

INTERVENTIONS

Peripheral laser photocoagulation along the demarcation lines for confining the detachment area in both eyes was performed with a stable condition during follow up.

OUTCOMES

After laser retinopexy, the patient was followed up at one week and four months later with stable laser scars and without progression of the retinal detachments.

CONCLUSION

Regressed ROP-associated retinal detachment can occur at any time during life. Special care and follow-up may be necessary for these patients.

Bilateral Retinoblastoma Presenting in an in vitro Fertilization Infant with Retinopathy of Prematurity

Retinopathy of prematurity (ROP) and retinoblastoma (RB) are well-described entities in premature babies. Although their pathogeneses are different, with ROP representing a disorder of interrupted development and RB a genetic disease, a few co-occurring cases have been reported, raising the possibility that the 2 conditions. Here, we report the sixth such case of co-occurring ROP and RB in an 8-month-old infant conceived by in vitro fertilization (IVF) who developed bilateral retinoblastoma a few months after treatment for advanced-stage ROP. While the ROP was initially adequately managed, bilateral RB necessitated bilateral enucleation. This case raises a number of important questions about whether IVF, ROP, and RB are causally related. Although the associations between IVF, ROP, and RB are likely to be coincidental, this case nevertheless highlights that ROP patients require regular follow-up for early diagnosis and treatment of ocular sequelae including RB.

The impact of distance cataract surgical wet laboratory training on cataract surgical competency of ophthalmology residents

BACKGROUND

This study assessed the impact of distance cataract surgical wet laboratory training on surgical competency of ophthalmology residents at a tertiary-level ophthalmic training center in Trujillo, Peru.

METHODS

Three five-week distance wet lab courses were administered through Cybersight, Orbis International's telemedicine platform. Weekly lectures and demonstrations addressed specific steps in phacoemulsification surgery. Each lecture had two accompanying wet lab assignments, which residents completed and recorded in their institution's wet lab and uploaded to Cybersight for grading. Competency was assessed through anonymous grading of pre- and post-training surgical simulation videos, masked as to which occurred before and after training, using a standardized competency rubric adapted from the Ophthalmology Surgical Competency Assessment Rubric (OSCAR, scale of 0-32). Day one best-corrected post-operative visual acuity (BVCA) was assessed in the operative eye on the initial consecutive 4-6 surgeries conducted by the residents as per the norms of their residency training. An anonymous post-training satisfaction survey was administered to trainees'.

RESULTS

In total, 21 ophthalmic residents participated in the courses, submitting a total of 210 surgical videos. Trainees' average competency score increased 6.95 points (95%CI [4.28, 9.62], SD = 5.01, p < 0.0001, two sample t-test) from 19.3 (95%CI [17.2, 21.5], SD = 4.04) to 26.3 (95%CI [24.2, 28.3], SD = 3.93). Visual acuity for 92% of post-training resident surgeries (n = 100) was ≥20/60, meeting the World Health Organization's criterion for good quality.

CONCLUSIONS

Structured distance wet lab courses in phacoemulsification resulted in significantly improved cataract surgical skills. This model could be applicable to locations where there are obstacles to traditional in-person training, such as the current COVID-19 pandemic.

Mesenchymal stem cell-derived secretomes for therapeutic potential of premature infant diseases

Preterm birth is a complex syndrome and remains a substantial public health problem globally. Its common complications include periventricular leukomalacia (PVL), bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC) and retinopathy of prematurity (ROP). Despite great advances in the comprehension of the pathogenesis and improvements in neonatal intensive care and associated medicine, preterm birth-related diseases remain essentially without adequate treatment and can lead to high morbidity and mortality. The therapeutic potential of mesenchymal stem/stromal cells (MSCs) appears promising as evidenced by their efficacy in preclinical models of pathologies relevant to premature infant complications. MSC-based therapeutic efficacy is closely associated with MSC secretomes and a subsequent paracrine action response to tissue injuries, which are complex and abundant in response to the local microenvironment. In the current review, we summarize the paracrine mechanisms of MSC secretomes underlying diverse preterm birth-related diseases, including PVL, BPD, NEC and ROP, are summarized, and focus is placed on MSC-conditioned media (CM) and MSC-derived extracellular vesicles (EVs) as key mediators of modulatory action, thereby providing new insights for future therapies in newborn medicine.

Therapeutic Effects of Mesenchymal Stromal Cell-Derived Small Extracellular Vesicles in Oxygen-Induced Multi-Organ Disease: A Developmental Perspective

Despite major advances in neonatal intensive care, infants born at extremely low birth weight still face an increased risk for chronic illness that may persist into adulthood. Pulmonary, retinal, and neurocognitive morbidities associated with preterm birth remain widespread despite interventions designed to minimize organ dysfunction. The design of therapeutic applications for preterm pathologies sharing common underlying triggers, such as fluctuations in oxygen supply or in the inflammatory state, requires alternative strategies that promote anti-inflammatory, pro-angiogenic, and trophic activities—ideally as a unitary treatment. Mesenchymal stem/stromal cell-derived extracellular vesicles (MEx) possess such inherent advantages, and they represent a most promising treatment candidate, as they have been shown to contribute to immunomodulation, homeostasis, and tissue regeneration. Current pre-clinical studies into the MEx mechanism of action are focusing on their restorative capability in the context of preterm birth-related pathologies, albeit not always with a multisystemic focus. This perspective will discuss the pathogenic mechanisms underlying the multisystemic lesions resulting from early-life disruption of normal physiology triggered by high oxygen exposures and pro-inflammatory conditions and introduce the application of MEx as immunomodulators and growth-promoting mediators for multisystem therapy.

School-based vision screening in Quetta, Pakistan: a qualitative study of experiences of teachers and eye care providers

Background

Visual impairment in children is a significant public health problem affecting millions of children globally. Many eye problems experienced by children can be easily diagnosed and treated. We conducted a qualitative study with teachers and optometrists involved in a school-based vision screening programme in Quetta district of Pakistan to explore their experiences of training, vision screening and referrals and to identify factors impacting on the effectiveness of the programme.

Methods

Between April 2018 and June 2018, we conducted semi-structured in-depth interviews with 14 teachers from eight purposefully selected schools with high rates of inaccurate (false positive) referrals. Interviews were also conducted with three optometrists from a not-for profit private eye care hospital that had trained the teachers. Interviews were audio recorded and professionally transcribed. NVIVO software version 12 was used to code and thematically analyze the data.

Results

Findings suggest that the importance of school-based vision screening was well understood and appreciated by the teachers and optometrists. Most participants felt that there was a strong level of support for the vision screening programme within the participating schools. However, there were a number of operational issues undermining the quality of screening. Eight teachers felt that the duration of the training was insufficient; the training was rushed; six teachers said that the procedures were not sufficiently explained, and the teachers had no time to practice. The screening protocol was not always followed by the teachers. Additionally, many teachers reported being overburdened with other work, which affected both their levels of participation in the training and the time they spent on the screening.

Conclusions

School-based vision screening by teachers is a cost-effective strategy to detect and treat children’s vision impairment early on. In the programme reviewed here however, a significant number of teachers over referred children to ophthalmic services, overwhelming their capacity and undermining the efficiency of the approach. To maximise the effectiveness and efficiency of school-based screening, future initiatives should give sufficient attention to the duration of the teacher training, experience of trainers, support supervision, refresher trainings, regular use of the screening guidelines, and the workload and motivation of those trained.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10404-9.

Development of a pediatric ophthalmology academic partnership between Canada and Ethiopia: a situational analysis

BACKGROUND

Educational capacity building in pediatric ophthalmology is necessary to address the burden of childhood blindness in Ethiopia. Residency and fellowship training at Addis Ababa University (AAU) have been enhanced with support from the University of Toronto (UofT), following the established Toronto Addis Ababa Academic Collaboration (TAAAC). Our aim was to assess the feasibility of implementing a pediatric ophthalmology fellowship at AAU with support from UofT, modeled by successful postgraduate medical education within TAAAC.

METHODS

A situational analysis, including a needs assessment, was conducted at Menelik II Hospital, Addis Ababa. Staff expertise, equipment and infrastructure were compared to International Council of Ophthalmology fellowship guidelines. Patient volumes were assessed through medical chart review. Local training needs were evaluated. A strategic working meeting facilitated program specification.

RESULTS

The faculty consisted of 11 ophthalmologists, including 2 pediatric specialists. Fourteen thousand six hundred twenty-seven medical and three thousand six hundred forty-one surgical pediatric cases were seen in the previous year. A 2-year fellowship incorporating anterior segment, retinoblastoma, strabismus, and retinopathy of prematurity modules was developed. Research collaborations, didactic teaching, and surgical supervision were identified as priorities requiring support. Quality standard indicators included faculty feedback, case log review and formal examination. Telemedicine, development of a larger eye hospital and partnerships to support equipment maintenance were identified as strategies to manage implementation barriers.

CONCLUSIONS

The situational analysis provided a way forward for the development of a pediatric ophthalmology fellowship, the first of its kind in Eastern Africa. Learning outcomes are feasible given high patient volumes, qualified staff supervision and sufficient equipment. Strategic partnerships may ensure resource sustainability.

Optical coherence tomography in the 2020s-outside the eye clinic

Optical coherence tomography (OCT) is a paragon of success in the translation of biophotonics science to clinical practice. OCT systems have become ubiquitous in eye clinics but access beyond this is limited by their cost, size and the skill required to operate the devices. Remarkable progress has been made in the development of OCT technology to improve the speed of acquisition, the quality of images and into functional extensions of OCT such as OCT angiography. However, more needs to be done to radically improve the access to OCT by addressing its limitations and enable penetration outside of typical clinical settings and into underserved populations. Beyond high-income countries, there are 6.5 billion people with similar eye-care needs, which cannot be met by the current generation of bulky, expensive and complex OCT systems. In addition, advancing the portability of this technology to address opportunities in point-of-care diagnostics, telemedicine and remote monitoring may aid development of personalised medicine. In this review, we discuss the major milestones in OCT hardware development to reach those beyond the eye clinic.

Prenatal intrauterine growth restriction and risk of retinopathy of prematurity

Low birthweight and decreased postnatal weight gain are known predictors of worse retinopathy of prematurity (ROP) but the role of prenatal growth patterns in ROP remains inconclusive. To distinguish small for gestational age (SGA) from intrauterine growth restriction (IUGR) as independent predictors of ROP, we performed a retrospective cohort study of patients who received ROP screening examinations at a level IV neonatal intensive care unit over a 7-year period. Data on IUGR and SGA status, worst stage of and need for treatment for ROP, and postnatal growth was obtained. 343 infants were included for analysis (mean gestational age = 28.6 weeks and birth weight = 1138.2 g). IUGR infants were more likely to have a worse stage of ROP and treatment-requiring ROP (both p < 0.0001) compared to non-IUGR infants. IUGR infants were more likely to be older at worst stage of ROP (p < 0.0001) and to develop postnatal growth failure (p = 0.01) than non-IUGR infants. Independent of postnatal growth failure status, IUGR infants had a 4-5 × increased risk of needing ROP treatment (p < 0.001) compared to non-IUGR infants. SGA versus appropriate for gestational age infants did not demonstrate differences in retinopathy outcomes, age at worst ROP stage, or postnatal growth failure. These findings emphasize the importance of prenatal growth on ROP development.

Cataract surgery in surgical camps: outcomes in a rural area of Cameroon

AIM

To assess the complications and visual outcomes of cataract surgery during an outreach eye camp in Cameroon in which two foreign ophthalmologists operate alongside a local one.

MATERIALS AND METHODS

This is a retrospective and comparative cohort study. The patients were consecutively assigned to three groups depending on the ophthalmologist who performed the cataract surgeries. All eyes underwent manual sutureless incision cataract surgery with posterior chamber intraocular lens (PCIOL) implantation under peribulbar anesthesia. Postoperative visits were scheduled for the first day, first week and second month after the procedures. Intra- and postoperative complications, best-corrected visual acuity and also refractive errors were assessed.

RESULTS

A total of 263 eyes underwent cataract extraction with PCIOL implantation. The percentage of eyes in which two or more lines of corrected distance visual acuity decreased were 2.4%, 2.7% and 0% for groups A, B and C, respectively. The percentage of eyes with good visual outcome (uncorrected distance visual acuity UDVA > 20/60) were, respectively, 82.09%, 81.43% and 80.82% for the three groups. Similar results were found between the three groups regarding complications. Ocular hypertension, transient corneal edema and hyphema were the incidences registered at the first postoperative control performed 24 h after surgery. The most common complication observed 2 months after surgery was posterior capsular opacity (2.6%).

CONCLUSION

High-volume cataract surgery in low- and middle-income countries may have good visual outcomes and a low rate of complications when the procedures are performed by either foreign or local ophthalmologists.

SYNOPSIS

A program of high-volume cataract surgery carried out in a rural environment with few resources can give good visual outcomes in the hands of both foreign and local experienced ophthalmologists.

The Muranga Teleophthalmology Study: A Comparison of Virtual (Teleretina) Assessment with in-person Clinical Examination to Diagnose Diabetic Retinopathy and Age-related Macular Degeneration in Kenya

PURPOSE:

This study compares a web-based teleophthalmology assessment with a clinical slit lamp examination to screen for diabetic retinopathy (DR) and age-related macular degeneration (AMD) among diabetic patients in a rural East African district.

METHODS:

Six hundred and twelve eyes from 306 diabetic patients underwent both a clinical slit lamp examination and a teleretina (TR) assessment by an experienced ophthalmologist. Both assessments were compared for any DR and AMD using the early treatment diabetic retinopathy study and age-related eye disease study grading scales, respectively.

RESULTS:

Of the 612 TR assessment photos, 74 (12%) were deemed ungradable due to media opacities, poor patient cooperation, or unsatisfactory photographs. The ability to detect DR and AMD showed a fair agreement (kappa statistic 0.27 and 0.23, respectively) between the TR and clinical slit lamp examination. Relative to a clinical slit lamp evaluation, a positive TR diagnosis carried a 75.0% positive predictive value when diagnosing DR and a 27.3% positive predictive value when diagnosing AMD. A negative TR diagnosis carried a 97.2% negative predictive value for the diagnosis of DR and a 98.1% negative predictive value for the diagnosis of AMD.

CONCLUSION:

When comparing TR assessments to clinical slit lamp examinations to diagnose DR and AMD, there was a fair agreement. Although further validation is needed, the TR approach provides a promising method to diagnose DR and AMD, two major causes of ocular impairment worldwide.

Development of Screening Criteria for Retinopathy of Prematurity in Ulaanbaatar, Mongolia, Using a Web-based Data Management System

PURPOSE

To describe a process for identifying birth weight (BW) and gestational age (GA) screening guidelines in Mongolia.

METHODS

This was a prospective cohort study in a tertiary care hospital in Ulaanbataar, Mongolia, of 193 premature infants with GA of 36 weeks or younger and/or BW of 2,000 g or less) with regression analysis to determine associations between BW and GA and the development of retinopathy of prematurity (ROP).

RESULTS

As BW and GA decreased, the relative risk of developing ROP increased. The relative risk of developing any stage of ROP in infants born at 29 weeks or younger was 2.91 (95% CI: 1.55 to 5.44; P < .001] compared to older infants. The relative risk of developing any type of ROP in infants with BW of less than 1,200 g was 2.41 (95% CI: 1.35 to 4.29; P = .003] and developing type 2 or worse ROP was 2.05 (95% CI: 0.99 to 4.25; P = .05).

CONCLUSIONS

Infants in Mongolia with heavier BW and older GA who fall outside of current United States screening guidelines of GA of 30 weeks or younger and/or BW of 1,500 g or less developed clinically relevant ROP. [J Pediatr Ophthalmol Strabismus. 2020;57(5):333-339.].

Automated detection of early-stage ROP using a deep convolutional neural network

BACKGROUND/AIM

To automatically detect and classify the early stages of retinopathy of prematurity (ROP) using a deep convolutional neural network (CNN).

METHODS

This retrospective cross-sectional study was conducted in a referral medical centre in Taiwan. Only premature infants with no ROP, stage 1 ROP or stage 2 ROP were enrolled. Overall, 11 372 retinal fundus images were compiled and split into 10 235 images (90%) for training, 1137 (10%) for validation and 244 for testing. A deep CNN was implemented to classify images according to the ROP stage. Data were collected from December 17, 2013 to May 24, 2019 and analysed from December 2018 to January 2020. The metrics of sensitivity, specificity and area under the receiver operating characteristic curve were adopted to evaluate the performance of the algorithm relative to the reference standard diagnosis.

RESULTS

The model was trained using fivefold cross-validation, yielding an average accuracy of 99.93%±0.03 during training and 92.23%±1.39 during testing. The sensitivity and specificity scores of the model were 96.14%±0.87 and 95.95%±0.48, 91.82%±2.03 and 94.50%±0.71, and 89.81%±1.82 and 98.99%±0.40 when predicting no ROP versus ROP, stage 1 ROP versus no ROP and stage 2 ROP, and stage 2 ROP versus no ROP and stage 1 ROP, respectively.

CONCLUSIONS

The proposed system can accurately differentiate among ROP early stages and has the potential to help ophthalmologists classify ROP at an early stage.

Automated identification of retinopathy of prematurity by image-based deep learning

BACKGROUND

Retinopathy of prematurity (ROP) is a leading cause of childhood blindness worldwide but can be a treatable retinal disease with appropriate and timely diagnosis. This study was performed to develop a robust intelligent system based on deep learning to automatically classify the severity of ROP from fundus images and detect the stage of ROP and presence of plus disease to enable automated diagnosis and further treatment.

METHODS

A total of 36,231 fundus images were labeled by 13 licensed retinal experts. A 101-layer convolutional neural network (ResNet) and a faster region-based convolutional neural network (Faster-RCNN) were trained for image classification and identification. We applied a 10-fold cross-validation method to train and optimize our algorithms. The accuracy, sensitivity, and specificity were assessed in a four-degree classification task to evaluate the performance of the intelligent system. The performance of the system was compared with results obtained by two retinal experts. Moreover, the system was designed to detect the stage of ROP and presence of plus disease as well as to highlight lesion regions based on an object detection network using Faster-RCNN.

RESULTS

The system achieved an accuracy of 0.903 for the ROP severity classification. Specifically, the accuracies in discriminating normal, mild, semi-urgent, and urgent were 0.883, 0.900, 0.957, and 0.870, respectively; the corresponding accuracies of the two experts were 0.902 and 0.898. Furthermore, our model achieved an accuracy of 0.957 for detecting the stage of ROP and 0.896 for detecting plus disease; the accuracies in discriminating stage I to stage V were 0.876, 0.942, 0.968, 0.998 and 0.999, respectively.

CONCLUSIONS

Our system was able to detect ROP and differentiate four-level classification fundus images with high accuracy and specificity. The performance of the system was comparable to or better than that of human experts, demonstrating that this system could be used to support clinical decisions.

Prevalence and causes of vision loss in sub-Saharan Africa in 2015: magnitude, temporal trends and projections

Background

This study aimed to assess the prevalence and causes of vision loss in sub-Saharan Africa (SSA) in 2015, compared with prior years, and to estimate expected values for 2020.

Methods

A systematic review and meta-analysis assessed the prevalence of blindness (presenting distance visual acuity <3/60 in the better eye), moderate and severe vision impairment (MSVI; presenting distance visual acuity <6/18 but ≥3/60) and mild vision impairment (MVI; presenting distance visual acuity <6/12 and ≥6/18), and also near vision impairment (<N6 or N8 in the presence of ≥6/12 best-corrected distance visual acuity) in SSA for 1990, 2010, 2015 and 2020.

In SSA, age-standardised prevalence of blindness, MSVI and MVI in 2015 were 1.03% (80% uncertainty interval (UI) 0.39–1.81), 3.64% (80% UI 1.71–5.94) and 2.94% (80% UI 1.05–5.34), respectively, for male and 1.08% (80% UI 0.40–1.93), 3.84% (80% UI 1.72–6.37) and 3.06% (80% UI 1.07–5.61) for females, constituting a significant decrease since 2010 for both genders. There were an estimated 4.28 million blind individuals and 17.36 million individuals with MSVI; 101.08 million individuals were estimated to have near vision loss due to presbyopia. Cataract was the most common cause of blindness (40.1%), whereas undercorrected refractive error (URE) (48.5%) was the most common cause of MSVI. Sub-Saharan West Africa had the highest proportion of blindness compared with the other SSA subregions.

Conclusions

Cataract and URE, two of the major causes of blindness and vision impairment, are reversible with treatment and thus promising targets to alleviate vision impairment in SSA.

Diagnostic Accuracy of Ophthalmoscopy vs Telemedicine in Examinations for Retinopathy of Prematurity

Importance

Examinations for retinopathy of prematurity (ROP) are typically performed using binocular indirect ophthalmoscopy. Telemedicine studies have traditionally assessed the accuracy of telemedicine compared with ophthalmoscopy as a criterion standard. However, it is not known whether ophthalmoscopy is truly more accurate than telemedicine.

Objective

To directly compare the accuracy and sensitivity of ophthalmoscopy vs telemedicine in diagnosing ROP using a consensus reference standard.

Design, Setting, and Participants

This multicenter prospective study conducted between July 1, 2011, and November 30, 2014, at 7 neonatal intensive care units and academic ophthalmology departments in the United States and Mexico included 281 premature infants who met the screening criteria for ROP.

Exposures

Each examination consisted of 1 eye undergoing binocular indirect ophthalmoscopy by an experienced clinician followed by remote image review of wide-angle fundus photographs by 3 independent telemedicine graders.

Main Outcomes and Measures

Results of both examination methods were combined into a consensus reference standard diagnosis. The agreement of both ophthalmoscopy and telemedicine was compared with this standard, using percentage agreement and weighted κ statistics.

Results

Among the 281 infants in the study (127 girls and 154 boys; mean [SD] gestational age, 27.1 [2.4] weeks), a total of 1553 eye examinations were classified using both ophthalmoscopy and telemedicine. Ophthalmoscopy and telemedicine each had similar sensitivity for zone I disease (78% [95% CI, 71%-84%] vs 78% [95% CI, 73%-83%]; P > .99 [n = 165]), plus disease (74% [95% CI, 61%-87%] vs 79% [95% CI, 72%-86%]; P = .41 [n = 50]), and type 2 ROP (stage 3, zone I, or plus disease: 86% [95% CI, 80%-92%] vs 79% [95% CI, 75%-83%]; P = .10 [n = 251]), but ophthalmoscopy was slightly more sensitive in identifying stage 3 disease (85% [95% CI, 79%-91%] vs 73% [95% CI, 67%-78%]; P = .004 [n = 136]).

Conclusions and Relevance

No difference was found in overall accuracy between ophthalmoscopy and telemedicine for the detection of clinically significant ROP, although, on average, ophthalmoscopy had slightly higher accuracy for the diagnosis of zone III and stage 3 ROP. With the caveat that there was variable accuracy between examiners using both modalities, these results support the use of telemedicine for the diagnosis of clinically significant ROP.

Extracellular Vesicles as a Potential Therapy for Neonatal Conditions: State of the Art and Challenges in Clinical Translation

Despite advances in intensive care, several neonatal conditions typically due to prematurity affect vital organs and are associated with high mortality and long-term morbidities. Current treatment strategies for these babies are only partially successful or are effective only in selected patients. Regenerative medicine has been shown to be a promising option for these conditions at an experimental level, but still warrants further exploration for the development of optimal treatment. Although stem cell-based therapy has emerged as a treatment option, studies have shown that it is associated with potential risks and hazards, especially in the fragile population of babies. Recently, extracellular vesicles (EVs) have emerged as an attractive therapeutic alternative that holds great regenerative potential and is cell-free. EVs are nanosized particles endogenously produced by cells that mediate intercellular communication through the transfer of their cargo. Currently, EVs are garnering considerable attention as they are the key effectors of stem cell paracrine signaling and can epigenetically regulate target cell genes through the release of RNA species, such as microRNA. Herein, we review the emerging literature on the therapeutic potential of EVs derived from different sources for the treatment of neonatal conditions that affect the brain, retinas, spine, lungs, and intestines and discuss the challenges for the translation of EVs into clinical practice.

Chlamydiaceae: Diseases in Primary Hosts and Zoonosis

Bacteria of the Chlamydiaceae family are a type of Gram-negative microorganism typified by their obligate intracellular lifestyle. The majority of the members in the Chlamydiaceae family are known pathogenic organisms that primarily infect the host mucosal surfaces in both humans and animals. For instance, Chlamydia trachomatis is a well-known etiological agent for ocular and genital sexually transmitted diseases, while C. pneumoniae has been implicated in community-acquired pneumonia in humans. Other chlamydial species such as C. abortus, C. caviae, C. felis, C. muridarum, C. pecorum, and C. psittaci are important pathogens that are associated with high morbidities in animals. Importantly, some of these animal pathogens have been recognized as zoonotic agents that pose a significant infectious threat to human health through cross-over transmission. The current review provides a succinct recapitulation of the characteristics as well as transmission for the previously established members of the Chlamydiaceae family and a number of other recently described chlamydial organisms.