Retinopathy of prematurity in middle-income countries

Prevalence of retinopathy of prematurity in Iran: a systematic review and Meta-analysis

AIM

To estimate overall prevalence of retinopathy of prematurity (ROP) in Iran using a systematic review and Meta-analysis.

METHODS

A systematic review and Meta-analysis was performed of all published studies pertaining to prevalence of ROP using international and national electronic databases (ISI Web of Sciences, PubMed, Scopus, Google Scholar, SID, MagIran, and IranMedex) from their inception until May 2016 with standard keywords. Begg and Egger tests were used to examine the publication bias and Cochran test and I² statistics were used to evaluate the statistical heterogeneity. Pooled estimate of the prevalence of ROP were calculated using random effects Meta-analysis.

RESULTS

The publication bias assumption was rejected by Egger tests with P-value equal to 0.024. The results of Cochran test and I² statistics revealed substantial heterogeneity (Q=1099.02, df=25, I²=97.7%, P=0.001). The overall prevalence of ROP using the random effect model in Iran was 26.1% (95% CI: 20.3%-31.8%).

CONCLUSION

The prevalence of ROP is relatively high in Iran. Low birth weight and gestational age are significant risk factors for the disease. Improved care, including oxygen delivery and monitoring, for preterm babies in all facility settings would reduce the number of babies affected with ROP.

Advances in understanding and management of retinopathy of prematurity

The understanding, diagnosis, and treatment of retinopathy of prematurity have changed in the 70 years since the original description of retrolental fibroplasia associated with high oxygenation. It is now recognized that retinopathy of prematurity differs in appearance worldwide and as ever smaller and younger premature infants survive. New methods are being evaluated to image the retina, diagnose severe retinopathy of prematurity, and determine windows of time for treatment to save eyes and improve visual and neural outcomes. New treatments to promote physiologic retinal vascular development, vascular repair, and inhibit vasoproliferation by regulating proteins involved in vascular endothelial growth factor, insulin-like growth factor, or erythropoietin signaling. Reducing excessive oxidative/nitrosative stress and understanding progenitor cells and neurovascular and glial vascular interactions are being studied.

Assessment of a Tele-education System to Enhance Retinopathy of Prematurity Training by International Ophthalmologists-in-Training in Mexico

PURPOSE

To evaluate a tele-education system developed to improve diagnostic competency in retinopathy of prematurity (ROP) by ophthalmologists-in-training in Mexico.

DESIGN

Prospective, randomized cohort study.

PARTICIPANTS

Fifty-eight ophthalmology residents and fellows from a training program in Mexico consented to participate. Twenty-nine of 58 trainees (50%) were randomized to the educational intervention (pretest, ROP tutorial, ROP educational chapters, and posttest), and 29 of 58 trainees (50%) were randomized to a control group (pretest and posttest only).

METHODS

A secure web-based educational system was created using clinical cases (20 pretest, 20 posttest, and 25 training chapter-based) developed from a repository of over 2500 unique image sets of ROP. For each image set used, a reference standard ROP diagnosis was established by combining the clinical diagnosis by indirect ophthalmoscope examination and image-based diagnosis by multiple experts. Trainees were presented with image-based clinical cases of ROP during a pretest, posttest, and training chapters.

MAIN OUTCOME MEASURES

The accuracy of ROP diagnosis (e.g., plus disease, zone, stage, category) was determined using sensitivity and specificity calculations from the pretest and posttest results of the educational intervention group versus control group. The unweighted kappa statistic was used to analyze the intragrader agreement for ROP diagnosis by the ophthalmologists-in-training during the pretest and posttest for both groups.

RESULTS

Trainees completing the tele-education system had statistically significant improvements (P < 0.01) in the accuracy of ROP diagnosis for plus disease, zone, stage, category, and aggressive posterior ROP (AP-ROP). Compared with the control group, trainees who completed the ROP tele-education system performed better on the posttest for accurately diagnosing plus disease (67% vs. 48%; P = 0.04) and the presence of ROP (96% vs. 91%; P < 0.01). The specificity for diagnosing AP-ROP (94% vs. 78%; P < 0.01), type 2 ROP or worse (92% vs. 84%; P = 0.04), and ROP requiring treatment (89% vs. 79%; P < 0.01) was better for the trainees completing the tele-education system compared with the control group. Intragrader agreement improved for identification of plus disease, zone, stage, and category of ROP after completion of the educational intervention.

CONCLUSIONS

A tele-education system for ROP education was effective in improving the diagnostic accuracy of ROP by ophthalmologists-in-training in Mexico. This system has the potential to increase competency in ROP diagnosis and management for ophthalmologists-in-training from middle-income nations.

A mobile team for screening of retinopathy of prematurity in India: Cost - effectiveness, outcomes, and impact assessment

PURPOSE:

To study the cost effectiveness, outcomes and impact of retinopathy of prematurity (ROP) screening and management model for urban neonatal intensive care units (NICUs).

STUDY DESIGN:

Public health intervention study.

METHODS:

This study was conducted in 2013. Staff of a mobile unit assessed all infants aged less than 34 weeks of Gestation age at birth and/or birth weight 1700 GM or less admitted in five NICUs between 2013 and 2015. A trained ophthalmologist performed bedside ROP screening through dilated pupils using indirect ophthalmoscope. ROP was graded and managed as per the International Classification of Retinopathy of Prematurity treatment guidelines. Counseling and laser treatment were the interventions. The incidence, grade and determinants of ROP were estimated. Direct and indirect costs were calculated to estimate the unit cost of screening and managing a child with ROP using the model.

RESULTS:

The study sample included 102 preterm/underweight infants. The prevalence of ROP of different grades in either eye was 32% (95% Confidence Intervals (CI): 23.2–41.5). ROP stage I was present in 75% of these eyes. The model could help in preventing/reducing visual disability in 4 infants with advanced stages of ROP. The unit cost of ROP screening, identifying one child with ROP and addressing visual disability due to ROP was US $ 198.9, 596.7 and 4,137.4 respectively.

CONCLUSION:

A mobile screening is likely feasible and cost-effective method to detect ROP and offer timely intervention for NICU in urban areas with limited resources.

Screening Retinopathy of Prematurity in Extremely Low Birth Weight Infants in China and the Need for Earlier Screening Times

Purpose. To convey the need for a revised screening strategy for retinopathy of prematurity (ROP) for extremely low birth weight (ELBW) infants in China. Design. A retrospective longitudinal study. Methods. The medical charts of infants with a birth weight (BW) of less than 1 kg were reviewed. The infants were divided into three groups: group A, without ROP; group B, with ROP but not up to type 1 prethreshold or threshold ROP; group C, with type 1 prethreshold or threshold ROP. Data collected included gender, gestational age (GA), BW, postmenstrual age (PMA), age of onset of ROP, and age at which treatment was carried out, if required. Results. A total of 77 infants were involved. Fifty-six infants developed ROP at any stage and 38 infants developed type 1 prethreshold or threshold ROP. The mean BW and GA of infants in group A were significantly different compared with groups B and C. The mean PMA of onset of ROP in infants who developed mild ROP was 37 weeks compared with 34 weeks for infants who developed severe ROP. Conclusion. ELBW infants have a higher incidence of ROP in China which highlights the need for optimizing neonatal care for these infants. In ELBW infants, ROP tends to develop more severely when it occurs earlier. It is necessary for ELBW infants, especially for those with a BW less than 800 g or a GA less than 25 weeks, to be initially screened at an earlier time.

Retinopathy of Prematurity in Triplets

OBJECTIVES

To investigate the incidence, severity and risk factors of retinopathy of prematurity (ROP) in triplets.

MATERIALS AND METHODS

The medical records of consecutive premature triplets who had been screened for ROP in a single maternity hospital were analyzed and presence and severity of ROP; birth weight, gender, gestational age of the infant; route of delivery and the mode of conception were recorded.

RESULTS

A total of 54 triplets (40 males, 14 females) who were screened for ROP between March 2010 and February 2013 were recruited for the study. All triplets were delivered by Caesarean section and 36 (66.7%) were born following an assisted conception. During follow-up, seven (13%) of the infants developed ROP of any stage and two (3.7%) required laser photocoagulation. The mean gestational age of triplets with ROP was 27.6±1.5 (27-31) weeks whereas it was 32.0±1.5 (30-34) weeks in those without ROP (p=0.002). The mean birth weights of triplets with and without ROP were 1290.0±295.2 (970-1600) g and 1667.5±222.2 (1130-1960) g, respectively (p<0.001). The presence of ROP was not associated with gender (p=0.358) or mode of conception (p=0.674).

CONCLUSION

ROP in triplets seems to be mainly related to low gestational age and low birth weight. Further prospective randomized studies are necessary to demonstrate risk factors of ROP in triplets and to determine if and how gemelarity plays a role in the development of ROP.

Impact of improved neonatal care on the profile of retinopathy of prematurity in rural neonatal centers in India over a 4-year period

Purpose

To report the reduction in the incidence and severity of retinopathy of prematurity (ROP) in rural India over a 4-year period following the introduction of improved neonatal care practices.

Methods

The Karnataka Internet Diagnosis of Retinopathy of Prematurity program (KIDROP), is a tele-medicine network that screens for ROP in different zones of Karnataka state in rural India. North Karnataka is the most underdeveloped and remote zone of this program and did not have any ROP screening programs before the intervention of the KIDROP in 2011. Six government and eleven private neonatal centers in this zone were screened weekly. Specific neonatal guidelines for ROP were developed and introduced in these centers. They included awareness about risk factors, oxygen regulation protocols, use of pulse oxymetry, monitoring postnatal weight gain, nutritional best practices, and management of sepsis. The incidence and severity of ROP were compared before the guidelines were introduced (Jan 2011 to Dec 2012) and after the guidelines were introduced (July 2013 to June 2015).

Results

During this 4-year period, 4,167 infants were screened over 11,390 imaging sessions. The number of enrolled infants increased from 1,825 to 2,342 between the two periods (P<0.001). The overall incidence of any stage ROP reduced significantly from 26.8% to 22.4% (P<0.001). The incidence of treatment-requiring ROP reduced from 20.7% to 16% (P=0.06), and of the treated disease, aggressive posterior ROP reduced from 20.8% to 13.1% (P=0.23) following introduction of the guidelines.

Discussion

Rural neonatal centers in middle-income countries have a large, unscreened burden of ROP. Improving neonatal care in these centers can positively impact the incidence and severity of ROP even in a relatively short period. A combined approach of a robust ROP screening program and improved neonatal care practices is required to address the challenge.

COMPARING THE OUTCOME OF SINGLE VERSUS MULTIPLE SESSION LASER PHOTOABLATION OF FLAT NEOVASCULARIZATION IN ZONE 1 AGGRESSIVE POSTERIOR RETINOPATHY OF PREMATURITY: A Prospective Randomized Study

PURPOSE

To compare single versus 2-session laser photoablation for flat neovascularization in cases with Zone 1 aggressive posterior retinopathy of prematurity.

METHODS

Twenty-nine Asian Indian infants with aggressive posterior retinopathy of prematurity were randomized; each eye received 1 of 2 methods (29 each in Group A or B) proposed by the PHOTO-ROP group. Group A underwent single session laser to the avascular retina underlying the flat neovascularization by direct laser over the fronds. Group B underwent laser in 2 sessions; first, laser was delivered to the avascular periphery up to the flat neovascularization and 7 days later to the avascular bed exposed by the retraction of the fronds. Outcome and complications between the two groups were compared.

RESULTS

Mean birthweight and gestational ages were 1,276 g and 30.1 weeks, respectively. All eyes showed favorable outcome at a minimum 12-month follow-up. Hemorrhages after laser (41.4% vs. 17.2%, P < 0.001) were more common in the single laser group. Large hemorrhages (>1 disk diameter) seen in Group A took longer than 8 weeks to resolve and developed focal fibrosis.

CONCLUSION

This study demonstrates that the two-staged laser procedure produces fewer and smaller hemorrhages and no fibrosis compared with a single session. Both methods have comparable favorable outcomes in Asian Indian infants.

A novel small molecule ameliorates ocular neovascularisation and synergises with anti-VEGF therapy

Ocular neovascularisation underlies blinding eye diseases such as retinopathy of prematurity, proliferative diabetic retinopathy, and wet age-related macular degeneration. These diseases cause irreversible vision loss, and provide a significant health and economic burden. Biologics targeting vascular endothelial growth factor (VEGF) are the major approach for treatment. However, up to 30% of patients are non-responsive to these drugs and they are associated with ocular and systemic side effects. Therefore, there is a need for small molecule ocular angiogenesis inhibitors to complement existing therapies. We examined the safety and therapeutic potential of SH-11037, a synthetic derivative of the antiangiogenic homoisoflavonoid cremastranone, in models of ocular neovascularisation. SH-11037 dose-dependently suppressed angiogenesis in the choroidal sprouting assay ex vivo and inhibited ocular developmental angiogenesis in zebrafish larvae. Additionally, intravitreal SH-11037 (1 μM) significantly reduced choroidal neovascularisation (CNV) lesion volume in the laser-induced CNV mouse model, comparable to an anti-VEGF antibody. Moreover, SH-11037 synergised with anti-VEGF treatments in vitro and in vivo. Up to 100 μM SH-11037 was not associated with signs of ocular toxicity and did not interfere with retinal function or pre-existing retinal vasculature. SH-11037 is thus a safe and effective treatment for murine ocular neovascularisation, worthy of further mechanistic and pharmacokinetic evaluation.

Facilitated Versus Self-guided Training of Non-ophthalmologists for Grading Pre-plus and Plus Disease Using Fundus Images for Retinopathy of Prematurity Screening

PURPOSE

Retinopathy of prematurity (ROP) is an important cause of preventable blindness; barriers to screening necessitate novel approaches. Although trained non-ophthalmologists can accurately grade retinal images for ROP, effective training protocols are not established. This study compares the effectiveness of facilitated versus self-guided training of non-ophthalmologists for grading retinal images for pre-plus or plus disease in ROP.

METHODS

Forty-eight undergraduate and graduate students were trained to grade retinal images for the presence of pre-plus or plus disease. Students were randomly assigned to one of two training protocols. Both used identical electronic slideshows: one was guided by an in-person facilitator and the other was self-guided. After completing their respective training, students proficient in grading pre-plus and plus disease graded images in a telemedicine screening scenario. Accuracy of grading was compared to the reference standard of clinical examination.

RESULTS

Eighty-three percent (40 of 48) of trained students (91% in the facilitated vs 77% in the self-guided group, P = .26) were proficient and qualified to grade the ROP telemedicine screening scenario. Median accuracy for grading normal, pre-plus, or plus disease was 69% (70% in the facilitated vs 68% in the self-guided group, P = .91). When considering the designation of pre-plus or plus disease by graders as a screening test for detecting plus disease (confirmed on clinical examination), the median sensitivity and specificity of all students were 95% and 64%, respectively.

CONCLUSIONS

Both facilitated and self-guided teaching protocols yielded similar performance in ROP image grading for pre-plus or plus disease. Self-guided training protocols may be adequate to train non-ophthalmologists to grade retinal images for pre-plus and plus disease with high sensitivity. [J Pediatr Ophthalmol Strabismus. 2016;53(3):179-185.].

Hydrogen-rich Saline is ineffective in oxygen-induced retinopathy

AIMS

Hydrogen-rich saline (HRS) is a novel protection against various oxidative disorders and almost all types of inflammation. Moreover, its toxicity and side effects are rarely reported. We sought to clarify the protective effect of HRS against the oxygen-induced retinopathy (OIR) in C57BL/6 J model.

MAIN METHODS

The OIR in the HRS treated mice and the untreated controls were systematically compared. The retinas of both groups were analyzed using high-molecular-weight FITC-dextran staining of flat-mount preparations, hematoxylin and eosin (H&E) staining of cross-sections. The distribution and expression of the vascular endothelial growth factor (VEGF) were also evaluated by the immunohistochemical measurements between postnatal days 17 (P17) and P21.

KEY FINDING

The leakage and non-perfusion areas of retinal blood vessels were not alleviated in the HRS treatment group. Moreover, the number of preretinal vascular endothelial cell in the HRS treatment group was similar to that in the untreated group after exposure to hyperoxia (P>0.05). The degree of OIR was positively correlated with the expression level of VEGF. Intriguingly, the preretinal vascular endothelial cell count in the retinas of pups reared in room air with HRS treatment was 15.21±2.98. The preretinal vascular endothelial cell count of the HRS treated mice was significantly higher than that of the untreated group reared in room air.

SIGNIFICANCE

In summary, HRS therapy (at the dose of 10ml/day, applied between P12 and P17) did not inhibit retinal neovascularization in OIR; On the contrary, it would induce the retinal neovascularization during the development of normal retinas.

Retinopathy of prematurity: Past, present and future

Retinopathy of prematurity (ROP) is a vasoproliferative disorder of the retina occurring principally in new born preterm infants. It is an avoidable cause of childhood blindness. With the increase in the survival of preterm babies, ROP has become the leading cause of preventable childhood blindness throughout the world. A simple screening test done within a few weeks after birth by an ophthalmologist can avoid this preventable blindness. Although screening guidelines and protocols are strictly followed in the developed nations, it lacks in developing economies like India and China, which have the highest number of preterm deliveries in the world. The burden of this blindness in these countries is set to increase tremendously in the future, if corrective steps are not taken immediately. ROP first emerged in 1940s and 1950s, when it was called retrolental fibroplasia. Several epidemics of this disease were and are still occurring in different regions of the world and since then a lot of research has been done on this disease. However, till date very few comprehensive review articles covering all the aspects of ROP are published. This review highlights the past, present and future strategies in managing this disease. It would help the pediatricians to update their current knowledge on ROP.

ANALYSIS OF CHANGES IN CHARACTERISTICS OF SEVERE RETINOPATHY OF PREMATURITY PATIENTS AFTER SCREENING GUIDELINES WERE ISSUED IN CHINA

PURPOSE

To describe the changes in the characteristics of infants treated for severe retinopathy of prematurity (ROP) in a tertiary referral unit in China after screening guidelines were issued in 2004 and to evaluate the effectiveness of the current criteria.

METHODS

Information on consecutive infants referred to a single eye department for treatment of Stage 3 (Type 1 pretheshold and threshold disease), Stage 4, and Stage 5 ROP between January 2001 and May 2012 was retrieved from medical records.

RESULTS

The mean gestational age was 29.98 ± 2.13 weeks (range 26-34 weeks), and the mean birth weight was 1,414.32 ± 343.18 g (range 742-2,087 g). The proportion of infants with Stage 4 and Stage 5 ROP decreased statistically significantly over time (P = 0.026 and P < 0.001, respectively) after screening guidelines for ROP were issued in 2004. The median postmenstrual age when patients first visited the study hospital was 48.32 weeks (range 30-602 weeks); later presentation was significantly associated with more advanced ROP (P < 0.001). In addition, the postmenstrual age of first presentation showed a significant decrease over time (P < 0.001) after the screening guidelines were issued. The current Chinese screening guidelines cover 99.63% of infants while 9.07% of infants exceeded the U.K. screening criteria and 35.77% of infants exceeded the U.S. criteria.

CONCLUSION

After the government issued guidelines on ROP screening, the birth weight and gestational age of severe ROP patients remain similar. Big infants got severe ROP as before. But the awareness of ROP increased, the proportion of infants with retinal detachment caused by ROP decreased, and the infants received more timely treatment. The current ROP screening criteria are very effective.

Validation of the existing modified screening criteria for detection of all cases of Retinopathy of Prematurity in preterm babies - 11 year study from a governorate referral hospital in Oman

PURPOSE

To study appropriateness of our modified screening criteria for detection of all cases of Retinopathy of Prematurity (ROP) among preterm babies.

METHOD

Retrospective observational cohort study among preterm neonates who underwent ROP screening as per set protocol for 11 years at Nizwa Hospital, Al Dhakilya Governorate, Oman. We screened all babies with gestational age ⩽32 weeks or BW ⩽ 1500 g. Preterm babies >32 weeks of GA or BW > 1500 g with unstable clinical course believed to be at high risk by the attending neonatologist also were screened.

RESULTS

During the study period 528 babies were screened for ROP of which 76 babies were excluded due to death, associated congenital ocular malformation and loss for follow-up either due to transfer to other institution or defaulting. Thus 452 babies were included in the final analysis. Incidence of ROP was 46.4% of which 27.9% had mild ROP, 11.3% had severe ROP which regressed and 7.3% had severe ROP who were treated. The incidence of ROP among infants with GA < 26 wks, 26-28 wks, 29-30 wks, 31-32 wks and above 32 weeks was 100.0%, 80.0%, 59.3%, 34.4% and 19.4% respectively. 56 babies of this cohort belonged to Extended (modified) criteria group. Among these 12 babies had ROP out of which 9 had mild ROP and 3 had severe ROP. Among cases with severe ROP, two cases regressed spontaneously and one case needed treatment. Multivariate analysis using stepwise regression model showed statistically significant association of GA and BW to development of ROP. We would have missed few babies with ROP if we had followed other criteria.

CONCLUSION

Our modified screening criteria seem to be appropriate as no infant with severe ROP was missed during the study period. Incidence of severe ROP among babies in the extended criteria group (5.4%) is low but significant compared to lower gestational age. We plan to formulate a scoring system following all risk factor analysis to enable us to optimize the number of infants screened. Detection of all babies with ROP is important as they need long-term follow-up for the timely detection and management of associated ocular comorbidities.

Causes of Severe Visual Impairment and Blindness: Comparative Data From Bhutanese and Laotian Schools for the Blind

PURPOSE

To determine and compare the major causes of childhood blindness and severe visual impairment in Bhutan and Laos.

DESIGN

Independent cross-sectional surveys.

METHODS

This survey consists of 2 cross-sectional observational studies. The Bhutanese component was undertaken at the National Institute for Vision Impairment, the only dedicated school for the blind in Bhutan. The Laotian study was conducted at the National Ophthalmology Centre and Vientiane School for the Blind. Children younger than age 16 were invited to participate. A detailed history and examination were performed consistent with the World Health Organization Prevention of Blindness Eye Examination Record.

RESULTS

Of the 53 children examined in both studies, 30 were from Bhutan and 23 were from Laos. Forty percent of Bhutanese and 87.1% of Laotian children assessed were blind, with 26.7% and 4.3%, respectively, being severely visually impaired. Congenital causes of blindness were the most common, representing 45% and 43.5% of the Bhutanese and Laotian children, respectively. Anatomically, the primary site of blinding pathology differed between the cohorts. In Bhutan, the lens comprised 25%, with whole globe at 20% and retina at 15%, but in Laos, whole globe and cornea equally contributed at 30.4%, followed by retina at 17.4%. There was an observable difference in the rates of blindness/severe visual impairment due to measles, with no cases observed in the Bhutanese children but 20.7% of the total pathologies in the Laotian children attributable to congenital measles infection.

CONCLUSIONS

Consistent with other studies, there is a high rate of blinding disease, which may be prevented, treated, or ameliorated.

Incidence of Retinopathy of Prematurity in Bahrain, 2002-2011

PURPOSE

The purpose was to determine the incidence of retinopathy of prematurity (ROP) in Bahrain.

DESIGNS AND METHODS

premature infants (gestation age ≤32 weeks, birth weight ≤1500 g) admitted to the Neonatal Intensive Care Unit at Salmaniya Medical Complex were examined based on a predetermined screening protocol. The first examination was performed at 4-6 weeks of age, from January 1, 2002 to December 3, 2011. Data were collected on the type and incidence of each of ROP, birth weight, and age. Odds ratios and 95% confidence intervals (CI) were calculated.

RESULTS

A total of 1795 premature infants comprised the study population. Group 1 (<1000 g), and Group II (1000-1500 g), included 700 (39%) and 1095 (61%) infants. ROP was detected in 367 (20.4%) infants (95% CI = 18.6-22.3). The proportions of stage III ROP, stage III threshold disease requiring laser retinal photocoagulation and stage IV were 19%, 6%, and 1%, respectively. There were 68 (18.5%) infants with stage III ROP, 21 infants with Stage III ROP with threshold, and 5 infants with stage IV ROP requiring vitreoretinal surgery. There were 203 (80%) infants with a birth weight <1000 g. Birth weight of <1000 g was significantly associated to ROP [OR = 2.3 (95% CI = 1.8-2.9)].

CONCLUSION

One-fifth of premature infants had ROP in Bahrain. Birth weight <1000 g was a risk factor for ROP.

ER Stress and Angiogenesis

Proper tissue vascularization is vital for cellular function as it delivers oxygen, nutrients, hormones, and immune cells and helps to clear cellular debris and metabolic waste products. Tissue angiogenesis occurs to satisfy energy requirements and cellular sensors of metabolic imbalance coordinate vessel growth. In this regard, the classical pathways of the unfolded protein response activated under conditions of ER stress have recently been described to generate angiomodulatory or angiostatic signals. This review elaborates on the link between angiogenesis and ER stress and discusses the implications for diseases characterized by altered vascular homeostasis, such as cancer, retinopathies, and atherosclerosis.

Role of tele-medicine in retinopathy of prematurity screening in rural outreach centers in India - a report of 20,214 imaging sessions in the KIDROP program

Middle-income countries such as India are suffering from the third epidemic of retinopathy of prematurity (ROP). Improved survival and lower infant mortality rates have resulted in an increased number of preterm survivors in rural areas that unfortunately lack ROP specialists. We report our experience of a public-private partnership in rural India of an ongoing telemedicine program Karnataka Internet Assisted Diagnosis of Retinopathy of Prematurity program KIDROP that provides ROP screening by non-physicians. The analysis of 20,214 imaging sessions of 7106 from 36 rural centers in 77 months of activity are presented. The overall incidence of any stage and treatment requiring ROP was 22.39% and 3.57% respectively. We found a higher incidence of severe ROP in private (7.1%) vs government centers (1.7%). Fifty of the 254 babies (19.69%) who underwent treatment were outside the American screening guidelines cut-off. The report compares other "real-world" tele-ROP programs, summarizes the impact, and provides future strategies for outreach ROP screening in middle-income countries.

Infectious Ulcerative Keratitis Following Retinopathy of Prematurity Treatment

PURPOSE

To report the complication of infectious ulcerative keratitis after laser photocoagulation and pars plana vitrectomy (PPV) for retinopathy of prematurity (ROP).

METHODS

A retrospective chart review of infants treated for ROP with plus disease between 2004 and 2013 at University Hospital, Newark, New Jersey.

RESULTS

Of the 110 eyes (55 patients) that underwent treatment for ROP, 8 (7.27%) eyes were noted to develop infectious ulcerative keratitis in 4 neonates (4 eyes after laser photocoagulation and 4 eyes after PPV). All 8 eyes that developed ulcerative keratitis had a preceding corneal epithelial defect followed by corneal stromal haze. Seven of 8 eyes developed epithelial defect within 8 days of the procedure. All epithelial defects progressed to ulcerative keratitis within 7 days. A total of 10 (9.1%) eyes developed postoperative epithelial defects, and 8 (80%) of these eyes were ultimately diagnosed as having ulcerative keratitis. Four (4.08%) of 98 eyes treated with laser photocoagulation alone developed infective ulcerative keratitis, compared to 4 (33.33%) of 12 eyes treated with PPV. Because keratitis healed, corneal opacification ensued and covered 10% to 90% of the corneal surface area. Five of the 8 eyes had positive culture of corneal scrapings: 2 grew coagulase-negative Staphylococcus and Stenotrophamonas; 1 grew coagulase-negative Staphylococcus; 1 grew Streptococcus viridans, and 1 grew Staphylococcus hominis, Streptococcus mitis, and Streptococcus viridans. All 8 eyes were treated with antibiotic eye drops.

CONCLUSIONS

Infectious ulcerative keratitis developed in a small, but significant, percentage of patients undergoing treatment for ROP. Postoperative corneal epithelial defects with subsequent corneal haze appear to be involved in the progression to ulcerative keratitis.

Causes of childhood blindness in a developing country and an underdeveloped country

INTRODUCTION

The causes of childhood blindness depend on factors such as geographic location or the human development index of the populations under study. The main causes in developed countries are genetic and hereditary diseases, while infectious and contagious diseases, together with nutritional and vitamin deficiencies, are the main causes in underdeveloped countries (UDCs).

METHODS

Study of the causes of blindness among children admitted to a regional centre in Nador, Morocco, and among children in Mekele, Ethiopia. The study was carried out in collaboration with two non-governmental organizations based in Madrid, Spain. First, we worked with Fudación Adelias in June 2010, and with Proyecto Visión in October 2012.

RESULTS

The study comprised a total of 27 children in Morocco and 85 in Ethiopia. The average age of the children was 10.92 and 6.94 years, respectively. The main causes of blindness in Morocco were hereditary pathologies (25.92%) and refractive errors (14.82%), although trauma (7.40%) and corneal disease (7.40%) are relevant. Among the children from Ethiopia, corneal disease (27.05%) and trauma (20%) were the main causes of blindness, while congenital and hereditary diseases had a lower prevalence (4.70%).

CONCLUSIONS

The causes of blindness depend on the human development index of the populations under study. While corneal disease and trauma are the main causes observed in UDCs like Ethiopia, hereditary pathologies and refractive errors are the main causes within the Moroccan population studied. A mixed form can be observed in this country, as the cause of blindness found in developed countries, such as congenital and hereditary pathologies which are present alongside the causes normally found in LDCs.

Comparative study of RetCamRetCam II vs. binocular ophthalmoscopy in a screening program for retinopathy of prematurity

OBJECTIVE

To determine the performance of RetCam vs. binocular ophthalmoscopy (BIO) in a screening program for retinopathy of prematurity (ROP).

METHODS

Observational comparative study with prospective data collection. Examinations with RetCam (n=169) were performed on 83 infants included in a screening program for ROP and stored for analysis at a later stage. An experienced ophthalmologist examined the ocular fundus with binocular indirect ophthalmoscopy (BIO). The RetCam images were assessed for the presence of ROP, zone, grade, and presence of plus disease. RetCam and BIO data were compared by visually to estimate sensitivity, specificity, positive (VPP) and negative (VPN) predictive values.

RESULTS

ROP disease was detected in 108 eyes with BIO, and in 74 with RetCam. Out of 306 eyes examined with RetCam, false negative results were found in 34 eyes, with no false positives. Sensitivity of RetCam exam vs. BIO was 0.68, and specificity was 0.99. Positive predictive value was 0.93 and negative predictive value was 0.85. All 34 ROP cases not detected with RetCam were in zone III or outer zone II. They were all mild and regressed spontaneously. No threshold ROP was missed with RetCam.

CONCLUSION

Binocular indirect ophthalmoscopy is the reference method for the diagnosis of ROP. RetCam may be used as an alternative for ROP screening.

Morphological features of retinal development in premature Chinese infants observed by computer-assisted indirect ophthalmoscope imaging

OBJECTIVE

To investigate retinal maturation in premature infants (gestation age <37 weeks). using computer-assisted indirect ophthalmoscope imaging.

METHODS

Premature infants at postmenstrual age 33-46 weeks, who underwent fundus examinations using computer-aided indirect ophthalmoscopy, were stratified into seven postmenstrual-age groups. Images of macular morphology, peripheral retinal vascularization and fundus pigmentation were compared.

RESULTS

The study included 268 infants in the following postmenstrual-age groups: 33-34 weeks (n = 19), 35-36 weeks (n = 37), 37-38 weeks (n = 49), 39-40 weeks (n = 55), 41-42 weeks (n = 49), 43-44 weeks (n = 34), and 45-46 weeks (n = 25). The macula matured with increasing postmenstrual age. A mature macula was observed in 92% of infants at 45-46 weeks. Complete vascularization was achieved at 41-42 weeks in the nasal retina and at 43-44 weeks in the temporal retina. The number of retinas with normal pigmentation increased with postmenstrual age (rising to 84% of infants at postmenstrual age 45-46 weeks).

CONCLUSIONS

Following premature birth, macular morphology, retinal vascularization and retinal pigmentation continue to develop. This study provides reference images of normal retinal development in premature infants.

Time at treatment of severe retinopathy of prematurity in China: recommendations for guidelines in more mature infants

PURPOSE

To investigate the postmenstrual (PMA) age at treatment of severe retinopathy of prematurity (i.e. Type 1 prethreshold or threshold) in infants in a tertiary referral center in China.

PRINCIPAL FINDINGS

76.6% (359/469) of infants were treated for threshold disease. 67.5% (317/469) of infants had a birth weight (BW) of 1250 g or above and almost 30% (126) had a gestational age (GA) of 32 weeks or above. There was little difference in the characteristics of infants treated for Type 1 prethreshold or threshold ROP. After controlling for GA, PMA age at treatment was highest in infants with BW ≥2000 g (mean PMA 40.3±4.4 weeks, p<0.001); after controlling for BW, higher GA was associated with higher PMA at treatment (mean PMA 41.5 weeks for gestational age >34 weeks, p<0.001). For every three weeks increase in GA there was a two-week increase in PMA at treatment (R2 = 0.20, p<0.001). The time at treatment of Type 1 prethreshold disease was similar to that for threshold disease i.e. chronological age 5.6∓7.4 weeks, or PMA 34.1∓40.2 weeks but the lower end of the 95% confidence interval for chronological age for Type 1 prethreshold disease among infants with BW ≥2000 g was 3.7 weeks (i.e. before the recommended interval of 4∓6 weeks after birth).

SIGNIFICANCE

The Chinese guidelines regarding timing of the first examination are appropriate for infants with BW <2000 g, but more mature infants should be examined a little earlier, at 3 weeks after birth, in order to detect Type 1 prethreshold disease which has a better prognosis than threshold.

Intravitreal bevacizumab monotherapy for type-1 prethreshold, threshold, and aggressive posterior retinopathy of prematurity - 27 month follow-up results from Turkey

PURPOSE

To study the efficacy of intravitreal bevacizumab (IVB) injection as a single treatment for retinopathy of prematurity (ROP).

METHODS

This was a prospective interventional case series study performed in a clinical practice setting; a total of 122 patients including prethreshold (type 1) (n  = 79, 152 eyes, six unilateral), threshold (n = 12, 24 eyes), and aggressive posterior (APROP) (n = 31, 62 eyes); cases were included without any randomization or masking. A total of 253 IVB injections, 238 in the first session, 11 in the second session, and four in the third session were performed, and followed up for a mean of 89.155 ± 4.277 (range 82 to 105) weeks of postmenstrual age (PMA). Regression of ROP, maturation of the retina, and associated complications were evaluated.

RESULTS

Total regression was achieved in 227/238 eyes (95.4 %) after the first dose injection. The remaining 11 received a second injection, after which an additional seven (234/238; 98.2 %) regressed; after the third injection, the remaining 4 (238/238; 100 %) regressed. Complete retinal vascular maturation was achieved without any significant complications in all of the cases.

CONCLUSIONS

IVB injection as monotherapy seems to be a very effective treatment modality for ROP. Based on timely intervention, IVB as a single treatment modality can salvage almost all ROP cases before stage 4.

Retinal neurons curb inflammation and enhance revascularization in ischemic retinopathies via proteinase-activated receptor-2

Ischemic retinopathies are characterized by sequential vaso-obliteration followed by abnormal intravitreal neovascularization predisposing patients to retinal detachment and blindness. Ischemic retinopathies are associated with robust inflammation that leads to generation of IL-1β, which causes vascular degeneration and impairs retinal revascularization in part through the liberation of repulsive guidance cue semaphorin 3A (Sema3A). However, retinal revascularization begins as inflammation culminates in ischemic retinopathies. Because inflammation leads to activation of proteases involved in the formation of vasculature, we hypothesized that proteinase-activated receptor (Par)-2 (official name F2rl1) may modulate deleterious effects of IL-1β. Par2, detected mostly in retinal ganglion cells, was up-regulated in oxygen-induced retinopathy. Surprisingly, oxygen-induced retinopathy-induced vaso-obliteration and neovascularization were unaltered in Par2 knockout mice, suggesting compensatory mechanisms. We therefore conditionally knocked down retinal Par2 with shRNA-Par2-encoded lentivirus. Par2 knockdown interfered with normal revascularization, resulting in pronounced intravitreal neovascularization; conversely, the Par2 agonist peptide (SLIGRL) accelerated normal revascularization. In vitro and in vivo exploration of mechanisms revealed that IL-1β induced Par2 expression, which in turn down-regulated sequentially IL-1 receptor type I and Sema3A expression through Erk/Jnk-dependent processes. Collectively, our findings unveil an important mechanism by which IL-1β regulates its own endothelial cytotoxic actions by augmenting neuronal Par2 expression to repress sequentially IL-1 receptor type I and Sema3A expression. Timely activation of Par2 may be a promising therapeutic avenue in ischemic retinopathies.

Long term refractive and structural outcome following laser treatment for zone 1 aggressive posterior retinopathy of prematurity

AIM

To report the long term refractive, visual and structural outcome post-laser for zone 1 aggressive posterior retinopathy of prematurity (AP-ROP).

MATERIALS AND METHODS

A retrospective analysis was performed of refractive status of premature infants with zone 1 AP-ROP who underwent laser photocoagulation from 2002 to 2007 and followed up till 2013. Once the disease regressed, children were followed up six monthly with detailed examination regarding fixation pattern, ocular motility, nystagmus, detailed anterior segment and posterior segment examination, and refractive status including best corrected visual acuity.

RESULTS

Forty-eight eyes of 25 infants were included in the study. Average follow-up was 6.91 years (range, 3.8-9.5years) after laser treatment. Astigmatism was noted in 43 out of 48 eyes (89.6%). Two eyes had simple myopia whereas three eyes had no refractive error.

CONCLUSION

After successful laser treatment for zone 1 retinopathy of prematurity (ROP), 94% of our cases developed refractive error. Although most had a favorable anatomical and visual outcome, long-term follow-up even after a successful laser treatment in ROP was necessary.

Analysis of Current Status and Strategies of Retinopathy of Prematurity Screening during 6 Years in Local Regions of China: Implication and Caution

Purpose. To understand the current status of retinopathy of prematurity (ROP) screening in a province of North China. Methods. We retrospectively analyzed 5651 cases with ROP screening in the Provincial Screening Center of Hebei Province from January 2008 to December 2013. Results. 14.98% of all ROP patients and 1.56% of severe ROP patients required treatment. All the severe ROP patients met the criteria of screening. Severe ROP patients were detected at recommended initial screening time (4-6 weeks after birth). The frequency of other ocular diseases was 8.03%, in which the main disease was fundus hemorrhage. In 2665 more mature and unqualified infants, only 2 retinoblastoma and 2 familial exudative vitreoretinopathy were detected, which indicates the advantage of early diagnosis and treatment based on fundus examination. Conclusions. It is suggested that the standard of GA < 32 weeks and/or BW < 1800 g could be served as the screening criteria in the local region for ROP screening. 4 weeks after birth is the most appropriate time for initial screening.

Intravitreal low-dosage bevacizumab for retinopathy of prematurity

PURPOSE

To report on the therapeutic effect of intravitreal low-dose bevacizumab for treatment for retinopathy of prematurity (ROP).

METHODS

The single-centre retrospective, non-comparative case series study included all infants who consecutively underwent intravitreal injection of 0.375 mg bevacizumab (0.03 ml) under light sedation in topical anaesthesia as therapy of ROP in zone I or zone II.

RESULTS

The clinical charts of 29 patients (57 eyes) with a median birth weight of 630 g (range: 290-1390 g) and median gestational age of 25 + 1 weeks (range: 23 + 1-30 weeks) were reviewed. Six children (12 eyes) were graded as ROP with zone I retinopathy and plus disease. The 23 remaining infants had extraretinal neovascularizations in zone II or partly zone I. The intravitreal bevacizumab injection was injected at a median age of 12 + 1 weeks (range: 7 + 4-21 + 4), the median follow-up was 4.2 months (range: from 3 days to 45.1 months). In all eyes treated, a regression of plus disease occurred within two to six days, retinal neovascularizations regressed within 2-3 weeks and pupillary rigidity improved. None except one child in exceptionally bad general health conditions needed a second intravitreal bevacizumab injection. In none of the infants, any ophthalmologic side-effects of the bevacizumab application were detected during the follow-up period.

CONCLUSIONS

The intravitreal injection of a low dose of 0.375 mg bevacizumab showed a high efficacy as treatment for ROP. The question arises whether the low dosage of bevacizumab as compared to the dosage of 0.625 mg bevacizumab may be preferred.

Retinal imaging in premature infants using the Pictor noncontact digital camera

PURPOSE

To evaluate, first, the feasibility of using Pictor, a new portable, noncontact digital fundus camera, to obtain high-quality retinal images of prematurely born infants and, second, the accuracy of grading these images for clinically significant posterior pole vascular changes, that is, pre-plus or plus disease, compared to indirect ophthalmoscopy.

METHODS

Pictor retinal images were obtained on a convenience sample of prematurely born infants during routine examinations for retinopathy of prematurity (ROP). Images were reviewed and graded by two ROP experts, who were masked to demographic and clinical examination findings.

RESULTS

A total of 96 eyes of 48 infants were included. The mean field of view was 5.0 × 6.1 disk diameters (DD). Grader 1 found quality to be fair or good in 96% of images; grader 2 in 97% of images. Grader 1 judged images as having at least 1 DD length of a major vessel in 3 or 4 quadrants in 80% of images; grader 2 in 86% of images. The sensitivity and specificity of grading pre-plus or plus disease on Pictor images was 100% and 79%, respectively, for grader 1, and 83% and 85%, respectively, for grader 2, compared to the reference standard of indirect ophthalmoscopy.

CONCLUSIONS

The Pictor fundus camera can capture digital retinal images of prematurely born infants that have quality sufficient for accurate expert grading in comparison to clinical examination. Pictor shows promise as an ROP screening tool.

Frequency of retinopathy of prematurity in premature neonates with a birth weight below 1500 grams and a gestational age less than 32 weeks: a study from a tertiary care hospital in a lower-middle income country…

INTRODUCTION

Retinopathy of prematurity (ROP) is a treatable cause of blindness in neonates. In Pakistan, ROP is often not recognized early because screening and treatment programs are not yet in place in most neonatal units, even in tertiary care hospitals. It is hoped that this report will help inform medical professionals of the magnitude of the problem and help to design appropriate management strategies.

OBJECTIVES

The aim was to determine the frequency of ROP in premature and very low birth weight (BW) neonates (BW<1500 g and gestational age (GA) <32 weeks).

STUDY DESIGN

Cross-sectional study.

STUDY SETTING

Neonatal intensive care unit (NICU) of a tertiary care hospital in Karachi, Pakistan.

STUDY DURATION

From June 2009 to May 2010.

SUBJECTS AND METHODS

Neonates with a Birth weight (BW) <1500 g and Gestational Age (GA) <32 weeks who were admitted to the NICU and received an eye examination, or were referred for a ROP eye examination as an outpatient, were included in the study. GA was estimated from intrauterine ultrasound findings. Neonates with major congenital malformations, syndromes or congenital cataracts or tumors of the eyes, and those that died before the eye examination or did not attend the out patients department for an eye examination, were excluded. The neonatal eye examination was performed by a trained ophthalmologist at 4 or 6 weeks of age.

RESULTS

Out of 86 neonates, ROP was identified in nine neonates (10.5%) at the first eye examination. ROP was significantly associated with BW (P = 0.037), GA (P = 0.033), and chronological age (P<0.001).

CONCLUSIONS

we identified ROP in 10.5% of neonates at first eye examination. Significant associations between ROP and a GA<32 weeks and a BW<1500 g were also observed.we also stress that serial follow-up of neonates at risk for ROP is important when making a final diagnosis.

Synthesis and mechanistic studies of a novel homoisoflavanone inhibitor of endothelial cell growth

Preventing pathological ocular angiogenesis is key to treating retinopathy of prematurity, diabetic retinopathy and age-related macular degeneration. At present there is no small molecule drug on the market to target this process and hence there is a pressing need for developing novel small molecules that can replace or complement the present surgical and biologic therapies for these neovascular eye diseases. Previously, an antiangiogenic homoisoflavanone was isolated from the bulb of a medicinal orchid, Cremastra appendiculata. In this study, we present the synthesis of a novel homoisoflavanone isomer of this compound. Our compound, SH-11052, has antiproliferative activity against human umbilical vein endothelial cells, and also against more ocular disease-relevant human retinal microvascular endothelial cells (HRECs). Tube formation and cell cycle progression of HRECs were inhibited by SH-11052, but the compound did not induce apoptosis at effective concentrations. SH-11052 also decreased TNF-α induced p38 MAPK phosphorylation in these cells. Intriguingly, SH-11052 blocked TNF-α induced IκB-α degradation, and therefore decreased NF-κB nuclear translocation. It decreased the expression of NF-κB target genes and the pro-angiogenic or pro-inflammatory markers VCAM-1, CCL2, IL8, and PTGS2. In addition SH-11052 inhibited VEGF induced activation of Akt but not VEGF receptor autophosphorylation. Based on these results we propose that SH-11052 inhibits inflammation induced angiogenesis by blocking both TNF-α and VEGF mediated pathways, two major pathways involved in pathological angiogenesis. Synthesis of this novel homoisoflavanone opens the door to structure-activity relationship studies of this class of compound and further evaluation of its mechanism and potential to complement existing antiangiogenic drugs.

A comparative analysis of avoidable causes of childhood blindness in Malaysia with low income, middle income and high income countries

To determine the avoidable causes of childhood blindness in Malaysia and to compare this to other middle income countries, low income countries and high income countries. Data were obtained from a school of the blind study by Patel et al. and analysed for avoidable causes of childhood blindness. Six other studies with previously published data on childhood blindness in Bangladesh, Ethiopia, Nigeria, Indonesia, China and the United Kingdom were reviewed for avoidable causes. Comparisons of data and limitations of the studies are described. Prevalence of avoidable causes of childhood blindness in Malaysia is 50.5 % of all the cases of childhood blindness, whilst in the poor income countries such as Bangladesh, Ethiopia, Nigeria and Indonesia, the prevalence was in excess of 60 %. China had a low prevalence, but this is largely due to the fact that most schools were urban, and thus did not represent the situation of the country. High income countries had the lowest prevalence of avoidable childhood blindness. In middle income countries, such as Malaysia, cataract and retinopathy of prematurity are the main causes of avoidable childhood blindness. Low income countries continue to struggle with infections such as measles and nutritional deficiencies, such as vitamin A, both of which are the main contributors to childhood blindness. In high income countries, such as the United Kingdom, these problems are almost non-existent.

A new paradigm for incorporating the joint statement screening guidelines for retinopathy of prematurity into clinical practice: outcomes from a quaternary referral program

BACKGROUND AND OBJECTIVE

This study examines patient experience at a quaternary referral pediatric clinic with a retinopathy of prematurity (ROP) screening program that monitors infants at least on a weekly basis for any stage of ROP.

PATIENTS AND METHODS

Admission records of 399 prematurely born patients treated at the Byers Eye Institute outpatient ROP clinic were retrospectively reviewed. Patients were categorized according to ROP status and whether they completed, canceled, or failed to show up for scheduled examinations. Demographic information was collected from medical records.

RESULTS

Of 1,823 scheduled ROP-related visits, 327 (17.9%) resulted in cancellations and 90 (4.9%) in no-shows, with 238 missed visits due to caregiver-related and 149 due to caregiver-unrelated reasons. Of 399 total patients, 142 (35.6%) canceled or failed to show up for at least one appointment because of caregiver-related reasons.

CONCLUSION

More than one-third of patients with ROP canceled or missed appointments. The true risk of delay is difficult to assess because all patients requiring treatment received it prior to discharge from the hospital. To achieve maximal compliance with joint statement guidelines on ROP screening, patients should be scheduled for examination earlier than recommended.

Oxygen-induced retinopathy induces short-term glial stress and long-term impairment of photoentrainment in mice

BACKGROUND

Retinopathy of prematurity is a serious potentially blinding disease of pre-term infants. There is extensive vascular remodeling and tissue stress, but data concerning alterations in retinal neurons and glia, and long-term functional sequelae are still incomplete.

METHODS

ROP was induced using the oxygen-induced retinopathy (OIR) mouse model. Postnatal day 7 (P7) 129SVE mice were exposed to hyperoxia (75 ± 0.5 % oxygen) for 5 days, and then returned to normoxia to induce OIR. Exposed animals were euthanized at 5 (P17-OIR) and 14 days (P26-OIR) after return to normal air, together with corresponding age-matched control mice (P17-C and P26-C respectively) raised only in room air. Their retinas were examined by immunohistochemistry using a battery of antibodies against key glial and neuronal proteins. A further group of OIR mice and controls were examined at 10 weeks of age for their ability to re-entrain to changing 12 h light/12 h dark cycles, assayed by wheel-running actimetry. In this protocol, animals were subjected to three successive conditions of 300 lux, 15 lux and 1 lux ambient light intensity coupled with 6 hours of jetlag. Animals were euthanized at 4 months of age and used in immunoblotting for rhodopsin.

RESULTS

Compared to P17-C, immunohistochemical staining of P17-OIR sections showed up-regulation of stress-related and glutamate-regulatory proteins in astrocytes and Müller glial cells. In contrast, glial phenotypic expression in P26-OIR retinas largely resembled that in P26-C. There was no loss in total retinal ganglion cells (RGC) at either P17-OIR or P26-OIR compared to corresponding controls, whereas intrinsically photosensitive RGC showed significant decreases, with 375 ± 13/field in P26-OIR compared to 443 ± 30/field in P26-C (p < 0.05). Wheel actimetry performed on control and OIR-treated mice at 4 months demonstrated that animals raised in hyperoxic conditions had impaired photoentrainment at low illuminance of 1 lux, as well as significantly reduced levels of rhodopsin compared to age-matched controls.

CONCLUSIONS

OIR leads to transient up-regulation of retinal glial proteins involved in metabolism, and partial degeneration of intrinsically photosensitive RGC and rod photoreceptors. OIR affects circadian photo-entrainment at low illuminance values, possibly by affecting the rod pathway and/or intrinsically photosensitive RGC input to the circadian clock. This study hence shows that retinopathy of prematurity affects light-regulated circadian behavior in an animal model, and may induce similar problems in humans.

The KIDROP model of combining strategies for providing retinopathy of prematurity screening in underserved areas in India using wide-field imaging, tele-medicine, non-physician graders and smart phone reporting

AIM

To report the Karnataka Internet Assisted Diagnosis of Retinopathy of Prematurity (KIDROP) program for retinopathy of prematurity (ROP) screening in underserved rural areas using an indigenously developed tele-ROP model.

MATERIALS AND METHODS

KIDROP currently provides ROP screening and treatment services in three zones and 81 neonatal units in Karnataka, India. Technicians were trained to use a portable Retcam Shuttle (Clarity, USA) and validated against ROP experts performing indirect ophthalmoscopy. An indigenously developed 20-point score (STAT score) graded their ability (Level I to III) to image and decide follow-up based on a three-way algorithm. Images were also uploaded on a secure tele-ROP platform and accessed and reported by remote experts on their smart phones (iPhone, Apple).

RESULTS

6339 imaging sessions of 1601 infants were analyzed. A level III technician agreed with 94.3% of all expert decisions. The sensitivity, specificity, positive predictive value and negative predictive value for treatment grade disease were 95.7, 93.2, 81.5 and 98.6 respectively. The kappa for technicians to decide discharge of babies was 0.94 (P < 0.001). Only 0.4% of infants needing treatment were missed.The kappa agreement of experts reporting on the iPhone vs. Retcam for treatment requiring and mild ROP were 0.96 and 0.94 (P < 0.001) respectively.

CONCLUSIONS

This is the first and largest real-world program to employ accredited non-physicians to grade and report ROP. The KIDROP tele-ROP model demonstrates that ROP services can be delivered to the outreach despite lack of specialists and may be useful in other middle-income countries with similar demographics.

Incidence and main risk factors for severe retinopathy of prematurity in infants weighing less than 1000 grams in Brazil

OBJECTIVES

This study evaluated the incidence and risk factors for severe retinopathy of prematurity (ROP) in babies <1000 g at Porto Alegre, Brazil.

METHODS

Prospective cohort study including premature children with birth weight ≤1000 g was conducted. Main outcome was the occurrence of severe ROP needing treatment.

RESULTS

A total of 157 infants were included. Severe ROP occurred in 20 infants (12.7%). Nineteen patients were treated by laser photocoagulation. Main risk factors for severe ROP were gestational age (P = 0.029), infant's weight measured at sixth week of life (P < 0.001) and number of days of oxygen therapy under mechanical ventilation (P < 0.001). After logistic regression, infant's weight at sixth week of life and number of days in mechanical ventilation were associated to severe ROP.

CONCLUSIONS

We reported the incidence of 12.7% of severe ROP among babies born ≤ 1000 g in our institution. Laser photocoagulation was effective to stabilize the disease among 19 treated patients.

Preterm-associated visual impairment and estimates of retinopathy of prematurity at regional and global levels for 2010

BACKGROUND

Retinopathy of prematurity (ROP) is a leading cause of potentially avoidable childhood blindness worldwide. We estimated ROP burden at the global and regional levels to inform screening and treatment programs, research, and data priorities.

METHODS

Systematic reviews and meta-analyses were undertaken to estimate the risk of ROP and subsequent visual impairment for surviving preterm babies by level of neonatal care, access to ROP screening, and treatment. A compartmental model was used to estimate ROP cases and numbers of visually impaired survivors.

RESULTS

In 2010, an estimated 184,700 (uncertainty range: 169,600-214,500) preterm babies developed any stage of ROP, 20,000 (15,500-27,200) of whom became blind or severely visually impaired from ROP, and a further 12,300 (8,300-18,400) developed mild/moderate visual impairment. Sixty-five percent of those visually impaired from ROP were born in middle-income regions; 6.2% (4.3-8.9%) of all ROP visually impaired infants were born at >32-wk gestation. Visual impairment from other conditions associated with preterm birth will affect larger numbers of survivors.

CONCLUSION

Improved care, including oxygen delivery and monitoring, for preterm babies in all facility settings would reduce the number of babies affected with ROP. Improved data tracking and coverage of locally adapted screening/treatment programs are urgently required.

Born too soon: care for the preterm baby

As part of a supplement entitled “Born Too Soon”, this paper focuses on care of the preterm newborn. An estimated 15 million babies are born preterm, and the survival gap between those born in high and low income countries is widening, with one million deaths a year due to direct complications of preterm birth, and around one million more where preterm birth is a risk factor, especially amongst those who are also growth restricted. Most premature babies (>80%) are between 32 and 37 weeks of gestation, and many die needlessly for lack of simple care. We outline a series of packages of care that build on essential care for every newborn comprising support for immediate and exclusive breastfeeding, thermal care, and hygienic cord and skin care. For babies who do not breathe at birth, rapid neonatal resuscitation is crucial. Extra care for small babies, including Kangaroo Mother Care, and feeding support, can halve mortality in babies weighing <2000 g. Case management of newborns with signs of infection, safe oxygen management and supportive care for those with respiratory complications, and care for those with significant jaundice are all critical, and are especially dependent on competent nursing care. Neonatal intensive care units in high income settings are de-intensifying care, for example increasing use of continuous positive airway pressure (CPAP) and this makes comprehensive preterm care more transferable. For health systems in low and middle income settings with increasing facility births, district hospitals are the key frontier for improving obstetric and neonatal care, and some large scale programmes now include specific newborn care strategies. However there are still around 50 million births outside facilities, hence home visits for mothers and newborns, as well as women’s groups are crucial for reaching these families, often the poorest. A fundamental challenge is improving programmatic tracking data for coverage and quality, and measuring disability-free survival. The power of parent’s voices has been important in high-income countries in bringing attention to preterm newborns, but is still missing from the most affected countries.

Basic fibroblast growth factor contributes to a shift in the angioregulatory activity of retinal glial (Müller) cells

Basic fibroblast growth factor (bFGF) is a pleiotropic cytokine with pro-angiogenic and neurotrophic effects. The angioregulatory role of this molecule may become especially significant in retinal neovascularization, which is a hallmark of a number of ischemic eye diseases. This study was undertaken to reveal expression characteristics of bFGF, produced by retinal glial (Müller) cells, and to determine conditions under which glial bFGF may stimulate the proliferation of retinal microvascular endothelial cells. Immunofluorescence labeling detected bFGF in Müller cells of the rat retina and in acutely isolated Müller cells with bFGF levels, which increased after ischemia-reperfusion in postischemic retinas. In patients with proliferative diabetic retinopathy or myopia, the immunoreactivity of bFGF co-localized to glial fibrillary acidic protein (GFAP)-positive cells in surgically excised retinal tissues. RT-PCR and ELISA analyses indicated that cultured Müller cells produce bFGF, which is elevated under hypoxia or oxidative stress, as well as under stimulation with various growth factors and cytokines, including pro-inflammatory factors. When retinal endothelial cells were cultured in the presence of media from hypoxia (0.2%)-conditioned Müller cells, a distinct picture of endothelial cell proliferation emerged. Media from 24-h cultured Müller cells inhibited proliferation, whereas 72-h conditioned media elicited a stimulatory effect. BFGF-neutralizing antibodies suppressed the enhanced endothelial cell proliferation to a similar extent as anti-VEGF antibodies. Furthermore, phosphorylation of extracellular signal-regulated kinases (ERK−1/−2) in retinal endothelial cells was increased when the cells were cultured in 72-h conditioned media, while neutralizing bFGF attenuated the activation of this signaling pathway. These data provide evidence that retinal (glial) Müller cells are major sources of bFGF in the ischemic retina. Müller cells under physiological conditions or transient hypoxia seem to provide an anti-angiogenic environment, but long-lasting hypoxia causes the release of bFGF, which might significantly co-stimulate neovascularization in the retina.

Alternative methods for the screening of retinopathy of prematurity: binocular indirect ophthalmoscopy vs wide-field digital retinal imaging

PURPOSE

To compare the diagnostic efficacy of wide-field digital retinal imaging (WFDRI) with binocular indirect ophthalmoscopy (BIO) for retinopathy of prematurity (ROP) screening.

METHODS

Premature infants admitted for ROP screening were included in this prospective, randomized and double-blind comparative study. They were examined by using BIO and WFDRI.

RESULTS

A total of 58 infants were enrolled in the study. The sensitivities of WFDRI in detecting any stage of ROP, treatment-requiring ROP and plus disease were 58.6, 100, and 100% respectively, with a specificity of 100% for all. The proportional agreement between WFDRI and BIO was 0.903 for detection of any stage of ROP, 1.0 for treatment-requiring ROP, and 1.0 for plus disease.

CONCLUSION

The sensitivity and specificity of WFDRI was excellent for the diagnosis of severe and treatment-requiring ROP. However, BIO was superior in mild ROP particularly for the ones in retinal periphery.

Preliminary study of retinal pathological features in preterm birth pups exposed to an animal model of oxygen-induced retinopathy in mice

BACKGROUND

The main risk factors of retinopathy of prematurity (ROP) are low gestational age and low birth weight, which are mainly caused by preterm birth. Currently, the animal model of oxygen-induced retinopathy (OIR) in mice is the most widely used model in ROP-associated studies. However, the experimental mice are normal-term pups, and may not mimic the pathogenic status of human ROP patients. In this study, we investigated the retinal pathological features in preterm birth pups exposed to an animal model of oxygen-induced retinopathy in mice.

METHODS

Preterm-birth mice were obtained from pregnant C57BL/6J mice that were induced by an intraperitoneal injection of lipopolysaccharide (LPS). The preterm and control mice were treated with high oxygen (75%) from postnatal day 7 (P7) to P12. The mice were perfused with high-molecular-weight FITC-dextran on P12, P15 and P17, and the retinas were whole-mounted and imaged. Vascular endothelial growth factor (VEGF) mRNA was also detected. Cross-sections of the retina were stained with hematoxylin and eosin (H&E) to identify preretinal neovascular tufts. For general observation, whole retinal images were also obtained using a microscope.

RESULTS

Leakage of the retinal blood vessels was aggravated in the preterm mice, particularly on P12 and P15. The non-perfused areas of the retina (pixel value, 183,673 ± 28,148 vs 132,110 ± 23,732, P = 0.009) and the number of preretinal endothelial cell nuclei were smaller (30.17 ± 8.33 vs 22.17 ± 6.74, P < 0.0001) on P17. The VEGF mRNA levels in the retinas were higher on P12 and P15 but lower on P17, compared with the control mice. Retinal hemorrhage was observed in the preterm mouse group (five out of six examined eyes).

CONCLUSIONS

Preterm-birth mice that were subject to OIR exhibited several pathological features, such as retinal hemorrhage, severe retinal leakage and moderate retinal neovascularization, which were similar to the clinical manifestations in ROP patients.

Retinopathy of prematurity-incidence today

Retinopathy of prematurity (ROP) in high-income countries now occurs, mostly in extreme low birth weight infants. In those countries, the incidence of ROP seems to have declined incrementally over the last few decades. But in middle-income countries, high rates of premature birth and increasing resuscitation of premature infants, often with suboptimal standards of care, have resulted in a third epidemic of ROP. Improved maternal and neonatal care, ROP screening guidelines appropriate for middle-income countries, and widespread timely treatment are urgently called for to control this third epidemic.