2-year outcomes of ranibizumab versus laser therapy for the treatment of very low birthweight infants with retinopathy of prematurity (RAINBOW extension study): prospective follow-up of an open label, randomised controlled trial

BACKGROUND

Intravitreal injection of vascular endothelial growth factor (VEGF) inhibitors is increasingly used to treat retinopathy of prematurity (ROP) in the absence of evidence about long-term efficacy or safety. In this prespecified interim analysis of the RAINBOW extension study, we aimed to prospectively assess outcomes at age 2 years.

METHODS

RAINBOW was an open-label, randomised trial that compared intravitreal ranibizumab (at 0·1 mg and 0·2 mg doses) with laser therapy for the treatment of ROP in very low birthweight infants (<1500 g). Families of the 201 infants that completed the RAINBOW core study were approached for consent to enter the extension study, which evaluates treatment outcomes prospectively through to 5 years of age. At age 20-28 months corrected for prematurity, participants had ophthalmic, development, and health assessments. The primary outcome was the absence of structural ocular abnormalities; secondary outcomes included vision-related quality of life (reported by parents using the Children's Visual Function Questionnaire), development (assessed with the Mullen Scales of Early Learning), motor function, and health status. Investigator-determined ocular and non-ocular serious and other adverse events were recorded. This study is registered with ClinicalTrials.gov, NCT02640664.

FINDINGS

Between June 16, 2016, and Jan 22, 2018, 180 infants were enrolled in the RAINBOW extension study, and 153 (85%) were evaluated at 20-28 months of age. No child developed new ocular structural abnormalities. Structural abnormalities were present in one (2%) of 56 infants in the ranibizumab 0·2 mg group, one (2%) of 51 infants in the 0·1 mg group, and four (9%) of 44 infants in the laser therapy group. The odds ratio of no structural abnormality was 5·68 (95% CI 0·60-54·0; p=0·10) for ranibizumab 0·2 mg versus laser therapy, 4·82 (0·52-45·0; p=0·14) for ranibizumab 0·1 mg versus laser therapy, and 1·21 (0·07-20; p=0·90) for ranibizumab 0·2 mg vs 0·1 mg. High myopia (-5 dioptres or worse) was less frequent after 0·2 mg ranibizumab (five [5%] of 110 eyes) than with laser therapy (16 [20%] of 82; odds ratio 0·19, 95% CI 0·05-0·69; p=0·012). Composite vision-related quality of life scores seemed higher among the ranibizumab 0·2 mg group (mean 84, 95% CI 80-88) compared with laser therapy (77, 72-83; p=0·063). Mullen Scales T-scores for visual reception, receptive and expressive language were distributed similarly between the three trial groups and there were similar proportions of infants with motor and hearing problems among treatment groups. The proportion of infants with respiratory symptoms and Z scores of standing height, weight, and head circumference were similarly distributed in the treatment groups. There were no adverse events considered by the investigator to be related to the study intervention.

INTERPRETATION

2-year outcomes following ranibizumab 0·2 mg for the treatment of ROP confirm the ocular outcomes of the original RAINBOW trial and show reduced high myopia, with possibly better vision-related quality of life. This treatment did not appear to affect non-ocular infant development.

FUNDING

Novartis Pharma AG.

An overall view of temperature oscillations in the solar chromosphere with ALMA

By direct measurements of the gas temperature, the Atacama Large Millimeter/submillimeter Array (ALMA) has yielded a new diagnostic tool to study the solar chromosphere. Here, we present an overview of the brightness-temperature fluctuations from several high-quality and high-temporal-resolution (i.e. 1 and 2 s cadence) time series of images obtained during the first 2 years of solar observations with ALMA, in Band 3 and Band 6, centred at around 3 mm (100 GHz) and 1.25 mm (239 GHz), respectively. The various datasets represent solar regions with different levels of magnetic flux. We perform fast Fourier and Lomb-Scargle transforms to measure both the spatial structuring of dominant frequencies and the average global frequency distributions of the oscillations (i.e. averaged over the entire field of view). We find that the observed frequencies significantly vary from one dataset to another, which is discussed in terms of the solar regions captured by the observations (i.e. linked to their underlying magnetic topology). While the presence of enhanced power within the frequency range 3-5 mHz is found for the most magnetically quiescent datasets, lower frequencies dominate when there is significant influence from strong underlying magnetic field concentrations (present inside and/or in the immediate vicinity of the observed field of view). We discuss here a number of reasons which could possibly contribute to the power suppression at around 5.5 mHz in the ALMA observations. However, it remains unclear how other chromospheric diagnostics (with an exception of Hα line-core intensity) are unaffected by similar effects, i.e. they show very pronounced 3-min oscillations dominating the dynamics of the chromosphere, whereas only a very small fraction of all the pixels in the 10 ALMA datasets analysed here show peak power near 5.5 mHz. This article is part of the Theo Murphy meeting issue 'High-resolution wave dynamics in the lower solar atmosphere'.

On the influence of magnetic topology on the propagation of internal gravity waves in the solar atmosphere

The solar surface is a continuous source of internal gravity waves (IGWs). IGWs are believed to supply the bulk of the wave energy for the lower solar atmosphere, but their existence and role for the energy balance of the upper layers is still unclear, largely due to the lack of knowledge about the influence of the Sun's magnetic fields on their propagation. In this work, we look at naturally excited IGWs in realistic models of the solar atmosphere and study the effect of different magnetic field topographies on their propagation. We carry out radiation-magnetohydrodynamic simulations of a magnetic field free and two magnetic models-one with an initial, homogeneous, vertical field of 100 G magnetic flux density and one with an initial horizontal field of 100 G flux density. The propagation properties of IGWs are studied by examining the phase-difference and coherence spectra in the kh - ω diagnostic diagram. We find that IGWs in the upper solar atmosphere show upward propagation in the model with predominantly horizontal field similar to the model without magnetic field. In contrast to that the model with predominantly vertical fields show downward propagation. This crucial difference in the propagation direction is also revealed in the difference in energy transported by waves for heights below 0.8 Mm. Higher up, the propagation properties show a peculiar behaviour, which require further study. Our analysis suggests that IGWs may play a significant role in the heating of the chromospheric layers of the internetwork region where horizontal fields are thought to be prevalent. This article is part of the Theo Murphy meeting issue 'High-resolution wave dynamics in the lower solar atmosphere'.

High-frequency oscillations in small chromospheric bright features observed with Atacama Large Millimetre/Submillimetre Array

We report detection of oscillations in brightness temperature, size and horizontal velocity of three small bright features in the chromosphere of a plage/enhanced-network region. The observations, which were taken with high temporal resolution (i.e. 2 s cadence) with the Atacama large millimetre/ submillimetre array (ALMA) in Band 3 (centred at 3 mm; 100 GHz), exhibit three small-scale features with oscillatory behaviour with different, but overlapping, distributions of period on the order of, on average, 90 ± 22 s, 110 ± 12 s and 66 ± 23 s, respectively. We find anti-correlations between perturbations in brightness, temperature and size of the three features, which suggest the presence of fast sausage-mode waves in these small structures. In addition, the detection of transverse oscillations (although with a larger uncertainty) may also suggest the presence of Alfvénic oscillations which are likely representative of kink waves. This work demonstrates the diagnostic potential of high-cadence observations with ALMA for detecting high-frequency magnetohydrodynamic waves in the solar chromosphere. Such waves can potentially channel a vast amount of energy into the outer atmosphere of the Sun. This article is part of the Theo Murphy meeting issue 'High-resolution wave dynamics in the lower solar atmosphere'.

Acoustic-gravity wave propagation characteristics in three-dimensional radiation hydrodynamic simulations of the solar atmosphere

There has been tremendous progress in the degree of realism of three-dimensional radiation magneto-hydrodynamic simulations of the solar atmosphere in the past decades. Four of the most frequently used numerical codes are Bifrost, CO5BOLD, MANCHA3D and MURaM. Here we test and compare the wave propagation characteristics in model runs from these four codes by measuring the dispersion relation of acoustic-gravity waves at various heights. We find considerable differences between the various models. The height dependence of wave power, in particular of high-frequency waves, varies by up to two orders of magnitude between the models, and the phase difference spectra of several models show unexpected features, including ±180° phase jumps. This article is part of the Theo Murphy meeting issue 'High-resolution wave dynamics in the lower solar atmosphere'.

Ranibizumab versus laser therapy for the treatment of very low birthweight infants with retinopathy of prematurity (RAINBOW): an open-label randomised controlled trial

BACKGROUND

Despite increasing worldwide use of anti-vascular endothelial growth factor agents for treatment of retinopathy of prematurity (ROP), there are few data on their ocular efficacy, the appropriate drug and dose, the need for retreatment, and the possibility of long-term systemic effects. We evaluated the efficacy and safety of intravitreal ranibizumab compared with laser therapy in treatment of ROP.

METHODS

This randomised, open-label, superiority multicentre, three-arm, parallel group trial was done in 87 neonatal and ophthalmic centres in 26 countries. We screened infants with birthweight less than 1500 g who met criteria for treatment for retinopathy, and randomised patients equally (1:1:1) to receive a single bilateral intravitreal dose of ranibizumab 0·2 mg or ranibizumab 0·1 mg, or laser therapy. Individuals were stratified by disease zone and geographical region using computer interactive response technology. The primary outcome was survival with no active retinopathy, no unfavourable structural outcomes, or need for a different treatment modality at or before 24 weeks (two-sided α=0·05 for superiority of ranibizumab 0·2 mg against laser therapy). Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, NCT02375971.

INTERPRETATION

Between Dec 31, 2015, and June 29, 2017, 225 participants (ranibizumab 0·2 mg n=74, ranibizumab 0·1 mg n=77, laser therapy n=74) were randomly assigned. Seven were withdrawn before treatment (n=1, n=1, n=5, respectively) and 17 did not complete follow-up to 24 weeks, including four deaths in each group. 214 infants were assessed for the primary outcome (n=70, n=76, n=68, respectively). Treatment success occurred in 56 (80%) of 70 infants receiving ranibizumab 0·2 mg compared with 57 (75%) of 76 infants receiving ranibizumab 0·1 mg and 45 (66%) of 68 infants after laser therapy. Using a hierarchical testing strategy, compared with laser therapy the odds ratio (OR) of treatment success following ranibizumab 0·2 mg was 2·19 (95% Cl 0·99-4·82, p=0·051), and following ranibizumab 0·1 mg was 1·57 (95% Cl 0·76-3·26); for ranibizumab 0·2 mg compared with 0·1 mg the OR was 1·35 (95% Cl 0·61-2·98). One infant had an unfavourable structural outcome following ranibizumab 0·2 mg, compared with five following ranibizumab 0·1 mg and seven after laser therapy. Death, serious and non-serious systemic adverse events, and ocular adverse events were evenly distributed between the three groups.

FINDINGS

In the treatment of ROP, ranibizumab 0·2 mg might be superior to laser therapy, with fewer unfavourable ocular outcomes than laser therapy and with an acceptable 24-week safety profile.

FUNDING

Novartis.

Resolution patterns and duration of retinal haemorrhages measured by two-dimensional retinal area pixel counts from sequential retinal imaging in childhood encephalopathies: a morphometric study

Objective

To determine the time to resolution of different-layered retinal haemorrhages (RHs), and to describe the main patterns of their resolution in a group of children with encephalopathies.

Methods and analysis

From a prospective study of 114 children with traumatic and non-traumatic encephalopathies, 429 selected individual RHs (iRHs) from 18 children were serially imaged from admission using a RetCam. Photoshop and Scion Imaging software allowed calculation of RH area in pixels.

Results

Two patterns of the resolution were recognised on the basis of area measurements: a progressive decrease (pattern A, 60% of iRHs), and a form of asymmetrical decay in which iRHs first increased in size before then progressively decreasing (pattern B, 35% of iRHs). Within the pattern A group, the Kaplan-Meier median survival time (MST) (95% CI) was 10 (9.3 to 10.7) days for intra-RHs (IRHs) and 38 (10.8 to 65.2) days for pre-RHs (PRHs), log rank (Mantel-Cox) p=0.001. The mean percentage reduction in area per day was 12.5% for all iRHs, 14.5% for IRHs and 6.3% for PRHs.

Conclusion

Serial area measurements of iRHs revealed that 35% haemorrhages became temporarily larger before decreasing to resolution. Serially imaged selected RHs showed a longer MST for PRHs than for IRHs.

Drag Reduction Using Polysaccharides in a Taylor⁻Couette Flow

Three different polysaccharides, aloe vera, Tamarind powder and pineapple fibers, are utilized as drag reducing agents in a turbulent flow. Using a Taylor–Couette setup, consisting of a rotating inner cylinder, for measuring the drag reduction, a range of Reynolds numbers from 4 × 10⁴ to 3 × 10⁵ has been explored in this study. The results are in good agreement with previous studies on polysaccharides conducted in a pipe/channel flow and a maximum drag reduction of 35% has been observed. Further, novel additives such as cellulose nanocrystals (CNC), surfactants and CNC grafted with surfactants are also examined in this study for drag reduction. CNC due to its rigid rod structure reduced the drag by 30%. Surfactant, due to its unique micelle formation showed maximum drag reduction of 80% at low Re. Further, surfactant was grafted on CNC and was examined for drag reduction. However, drag reduction property of surfactant was observed to be significantly reduced after grafting on CNC. The effect of Reynolds number on drag reduction is studied for all the additives investigated in this study.

Meta-analysis of gene-environment-wide association scans accounting for education level identifies additional loci for refractive error

Myopia is the most common human eye disorder and it results from complex genetic and environmental causes. The rapidly increasing prevalence of myopia poses a major public health challenge. Here, the CREAM consortium performs a joint meta-analysis to test single-nucleotide polymorphism (SNP) main effects and SNP × education interaction effects on refractive error in 40,036 adults from 25 studies of European ancestry and 10,315 adults from 9 studies of Asian ancestry. In European ancestry individuals, we identify six novel loci (FAM150B-ACP1, LINC00340, FBN1, DIS3L-MAP2K1, ARID2-SNAT1 and SLC14A2) associated with refractive error. In Asian populations, three genome-wide significant loci AREG, GABRR1 and PDE10A also exhibit strong interactions with education (P<8.5 × 10(-5)), whereas the interactions are less evident in Europeans. The discovery of these loci represents an important advance in understanding how gene and environment interactions contribute to the heterogeneity of myopia.

Correcting LCD luminance non-uniformity for threshold Saccadic Vector Optokinetic Perimetry (SVOP)

The accurate assessment of visual field function can provide valuable information on a range of visual disorders. Saccadic Vector Optokinetic Perimetry (SVOP) is a novel instrument for measuring supra-threshold visual fields in young children who are otherwise unable to perform Automated Static Perimetry (ASP). However, limitations in Liquid Crystal Display (LCD) technology restrict the ability of SVOP to determine threshold values at various points in the visual field, often required in detailed perimetry examinations. This paper introduces a purpose-specific LCD luminance non-uniformity compensation approach to address this limitation. Thorough quantitative evaluation identifies the effectiveness of the proposed approach in (i) compensating for luminance non-uniformities across an LCD, and (ii) enabling SVOP to perform accurate and precise threshold visual field tests. The findings demonstrate that SVOP provides a promising alternative to the current threshold ASP standard (Humphrey Field Analyser).

Saccadic Vector Optokinetic Perimetry (SVOP): a novel technique for automated static perimetry in children using eye tracking

Perimetry is essential for identifying visual field defects due to disorders of the eye and brain. However, young children are often unable to reliably perform the preferred method of visual field assessment known as automated static perimetry (ASP). This paper introduces a novel method of ASP specifically developed for children called Saccadic Vector Optokinetic Perimetry (SVOP). SVOP uses eye tracking to detect the natural saccadic eye response of gaze orientation towards visual field stimuli if they are seen. In this paper, the direction and magnitude of a sample of subject gaze responses to visual field stimuli is used to construct a software decision algorithm for use in SVOP. SVOP was clinically evaluated in a group of 24 subjects, comprising children and adults, with and without visual field defects, by comparison with an equivalent test on the Humphrey Field Analyser (HFA). SVOP provides promising visual field test results when compared with the reference HFA test, and has proven extremely useful in detecting visual field defects in children unable to perform traditional ASP.

International photographic classification and grading system for myopic maculopathy

PURPOSE

To develop a classification and grading system for myopic maculopathy.

DESIGN

Development and evaluation of a classification system for myopic maculopathy based on observational case series.

METHODS

A comprehensive set of myopic macular lesions was defined via literature review and through consensus meetings among retinal specialists and clinician scientists. A classification of myopic maculopathy was formulated based on fundus photographs and a modified Delphi process and consensus. Inter- and intraobserver reproducibility, assessed as agreement (%) and weighted kappa values, were evaluated. One hundred retinal photographs with myopia and myopic macular lesions were selected from case series at the High Myopia Clinic of the Tokyo Medical and Dental University, Tokyo, Japan.

RESULTS

We defined 5 categories of myopic maculopathy including "no myopic retinal degenerative lesion" (Category 0), "tessellated fundus" (Category 1), "diffuse chorioretinal atrophy" (Category 2), "patchy chorioretinal atrophy" (Category 3), and "macular atrophy" (Category 4). Three additional features to supplement these categories were defined as "plus" lesions, namely, lacquer cracks, myopic choroidal neovascularization, and Fuchs spot. Posterior staphyloma was considered as a further, important sign of myopic retinopathy. The intraobserver agreement was ≥85% and the corresponding weighted kappa statistic was ≥0.6 between observations. After a brief training session, interobserver kappa statistics reached the predefined satisfactory level (≥0.4), considered as above moderate agreement.

CONCLUSIONS

We propose a classification system for myopic maculopathy that was found to be reproducible. Applying a uniform classification in different studies will facilitate communication and comparison of findings from clinical trials and epidemiologic studies.

Genome-wide association study for refractive astigmatism reveals genetic co-determination with spherical equivalent refractive error: the CREAM consortium

To identify genetic variants associated with refractive astigmatism in the general population, meta-analyses of genome-wide association studies were performed for: White Europeans aged at least 25 years (20 cohorts, N = 31,968); Asian subjects aged at least 25 years (7 cohorts, N = 9,295); White Europeans aged <25 years (4 cohorts, N = 5,640); and all independent individuals from the above three samples combined with a sample of Chinese subjects aged <25 years (N = 45,931). Participants were classified as cases with refractive astigmatism if the average cylinder power in their two eyes was at least 1.00 diopter and as controls otherwise. Genome-wide association analysis was carried out for each cohort separately using logistic regression. Meta-analysis was conducted using a fixed effects model. In the older European group the most strongly associated marker was downstream of the neurexin-1 (NRXN1) gene (rs1401327, P = 3.92E-8). No other region reached genome-wide significance, and association signals were lower for the younger European group and Asian group. In the meta-analysis of all cohorts, no marker reached genome-wide significance: The most strongly associated regions were, NRXN1 (rs1401327, P = 2.93E-07), TOX (rs7823467, P = 3.47E-07) and LINC00340 (rs12212674, P = 1.49E-06). For 34 markers identified in prior GWAS for spherical equivalent refractive error, the beta coefficients for genotype versus spherical equivalent, and genotype versus refractive astigmatism, were highly correlated (r = -0.59, P = 2.10E-04). This work revealed no consistent or strong genetic signals for refractive astigmatism; however, the TOX gene region previously identified in GWAS for spherical equivalent refractive error was the second most strongly associated region. Analysis of additional markers provided evidence supporting widespread genetic co-susceptibility for spherical and astigmatic refractive errors.

Genome-wide meta-analysis of myopia and hyperopia provides evidence for replication of 11 loci

Refractive error (RE) is a complex, multifactorial disorder characterized by a mismatch between the optical power of the eye and its axial length that causes object images to be focused off the retina. The two major subtypes of RE are myopia (nearsightedness) and hyperopia (farsightedness), which represent opposite ends of the distribution of the quantitative measure of spherical refraction. We performed a fixed effects meta-analysis of genome-wide association results of myopia and hyperopia from 9 studies of European-derived populations: AREDS, KORA, FES, OGP-Talana, MESA, RSI, RSII, RSIII and ERF. One genome-wide significant region was observed for myopia, corresponding to a previously identified myopia locus on 8q12 (p = 1.25×10⁻⁸), which has been reported by Kiefer et al. as significantly associated with myopia age at onset and Verhoeven et al. as significantly associated to mean spherical-equivalent (MSE) refractive error. We observed two genome-wide significant associations with hyperopia. These regions overlapped with loci on 15q14 (minimum p value = 9.11×10⁻¹¹) and 8q12 (minimum p value 1.82×10⁻¹¹) previously reported for MSE and myopia age at onset. We also used an intermarker linkage- disequilibrium-based method for calculating the effective number of tests in targeted regional replication analyses. We analyzed myopia (which represents the closest phenotype in our data to the one used by Kiefer et al.) and showed replication of 10 additional loci associated with myopia previously reported by Kiefer et al. This is the first replication of these loci using myopia as the trait under analysis. “Replication-level” association was also seen between hyperopia and 12 of Kiefer et al.'s published loci. For the loci that show evidence of association to both myopia and hyperopia, the estimated effect of the risk alleles were in opposite directions for the two traits. This suggests that these loci are important contributors to variation of refractive error across the distribution.

Nine loci for ocular axial length identified through genome-wide association studies, including shared loci with refractive error

Refractive errors are common eye disorders of public health importance worldwide. Ocular axial length (AL) is the major determinant of refraction and thus of myopia and hyperopia. We conducted a meta-analysis of genome-wide association studies for AL, combining 12,531 Europeans and 8,216 Asians. We identified eight genome-wide significant loci for AL (RSPO1, C3orf26, LAMA2, GJD2, ZNRF3, CD55, MIP, and ALPPL2) and confirmed one previously reported AL locus (ZC3H11B). Of the nine loci, five (LAMA2, GJD2, CD55, ALPPL2, and ZC3H11B) were associated with refraction in 18 independent cohorts (n = 23,591). Differential gene expression was observed for these loci in minus-lens-induced myopia mouse experiments and human ocular tissues. Two of the AL genes, RSPO1 and ZNRF3, are involved in Wnt signaling, a pathway playing a major role in the regulation of eyeball size. This study provides evidence of shared genes between AL and refraction, but importantly also suggests that these traits may have unique pathways.

Meta-analysis of genome-wide association studies in five cohorts reveals common variants in RBFOX1, a regulator of tissue-specific splicing, associated with refractive error

Visual refractive errors (REs) are complex genetic traits with a largely unknown etiology. To date, genome-wide association studies (GWASs) of moderate size have identified several novel risk markers for RE, measured here as mean spherical equivalent (MSE). We performed a GWAS using a total of 7280 samples from five cohorts: the Age-Related Eye Disease Study (AREDS); the KORA study ('Cooperative Health Research in the Region of Augsburg'); the Framingham Eye Study (FES); the Ogliastra Genetic Park-Talana (OGP-Talana) Study and the Multiethnic Study of Atherosclerosis (MESA). Genotyping was performed on Illumina and Affymetrix platforms with additional markers imputed to the HapMap II reference panel. We identified a new genome-wide significant locus on chromosome 16 (rs10500355, P = 3.9 × 10(-9)) in a combined discovery and replication set (26 953 samples). This single nucleotide polymorphism (SNP) is located within the RBFOX1 gene which is a neuron-specific splicing factor regulating a wide range of alternative splicing events implicated in neuronal development and maturation, including transcription factors, other splicing factors and synaptic proteins.

Genome-wide meta-analyses of multiancestry cohorts identify multiple new susceptibility loci for refractive error and myopia

Refractive error is the most common eye disorder worldwide and is a prominent cause of blindness. Myopia affects over 30% of Western populations and up to 80% of Asians. The CREAM consortium conducted genome-wide meta-analyses, including 37,382 individuals from 27 studies of European ancestry and 8,376 from 5 Asian cohorts. We identified 16 new loci for refractive error in individuals of European ancestry, of which 8 were shared with Asians. Combined analysis identified 8 additional associated loci. The new loci include candidate genes with functions in neurotransmission (GRIA4), ion transport (KCNQ5), retinoic acid metabolism (RDH5), extracellular matrix remodeling (LAMA2 and BMP2) and eye development (SIX6 and PRSS56). We also confirmed previously reported associations with GJD2 and RASGRF1. Risk score analysis using associated SNPs showed a tenfold increased risk of myopia for individuals carrying the highest genetic load. Our results, based on a large meta-analysis across independent multiancestry studies, considerably advance understanding of the mechanisms involved in refractive error and myopia.

Genome-wide association analyses identify multiple loci associated with central corneal thickness and keratoconus

Central corneal thickness (CCT) is associated with eye conditions including keratoconus and glaucoma. We performed a meta-analysis on >20,000 individuals in European and Asian populations that identified 16 new loci associated with CCT at genome-wide significance (P < 5 × 10(-8)). We further showed that 2 CCT-associated loci, FOXO1 and FNDC3B, conferred relatively large risks for keratoconus in 2 cohorts with 874 cases and 6,085 controls (rs2721051 near FOXO1 had odds ratio (OR) = 1.62, 95% confidence interval (CI) = 1.4-1.88, P = 2.7 × 10(-10), and rs4894535 in FNDC3B had OR = 1.47, 95% CI = 1.29-1.68, P = 4.9 × 10(-9)). FNDC3B was also associated with primary open-angle glaucoma (P = 5.6 × 10(-4); tested in 3 cohorts with 2,979 cases and 7,399 controls). Further analyses implicate the collagen and extracellular matrix pathways in the regulation of CCT.

LTBP2 gene analysis in the GLC3C-linked family and 94 CYP1B1-negative cases with primary congenital glaucoma

PURPOSE

Primary congenital glaucoma (isolated trabeculodysgensis, PCG) generally presents between birth and 3 years of age. Recently, mutations in Latent Transforming Growth Factor (TGF)-beta Binding Protein 2 (LTBP2) have been reported in several families that were diagnosed with PCG, who actually had a more complex ocular phenotype with ectopia lentis and Marfanoid features. We screened this gene for mutations in the original Turkish GLC3C-linked PCG family and in a group of CYP1B1-negative British PCG cases and their matched normal control subjects.

METHODS

The 36-coding exons of the LTBP2 gene were sequenced in 94 familial or sporadic CYP1B1-negative PCG cases and 96 matched normal control subjects.

RESULTS

No disease-causing mutations were identified in the original GLC3C-linked family. Screening of LTBP2 in 94 PCG and 96 control subjects identified three novel synonymous variations (L429L, P680P, S1031S) in 12 PCG and seven control subjects. A novel heterozygous missense mutation (R538W) was also identified in 1 of 90 PCG cases that is unlikely to be disease-causative.

CONCLUSIONS

LTBP2 mutations were not found in the Turkish GLC3C-linked PCG family or in 94 British CYP1B1-negative PCG cases. Our data suggest that LTBP2 mutations are not a significant cause for isolated trabeculodysgenesis.

New loci associated with central cornea thickness include COL5A1, AKAP13 and AVGR8

Central corneal thickness (CCT) is a highly heritable trait, which has been proposed to influence disorders of the anterior segment of the eye. A genome-wide association study (GWAS) of CCT was performed in 2269 individuals from three Croatian and one Scottish population. In the discovery set (1445 individuals), two genome-wide significant associations were identified for single nucleotide polymorphisms rs12447690 (β = 0.23 SD, P = 4.4 × 10(-9)) and rs1536482 (β = 0.22 SD, P = 7.1 × 10(-8)) for which the closest candidate genes (although ≥90 kb away) were zinc finger 469 (ZNF469) on 16q24.2 and collagen 5 alpha 1 (COL5A1) on 9q34.2, respectively. Only the ZNF469 association was confirmed in our replication set (824 individuals, P = 8.0 × 10(-4)) but COL5A1 remained a suggestive association in the combined sample (β = 0.16 SD, P = 1.1 × 10(-6)). Following a larger meta-analysis including recently published CCT GWAS summary data, COL5A1 was genome-wide significant (β = 0.13 SD, P = 5.1 × 10(-8)), together with two additional novel loci. The second new locus (defined by rs1034200) was 5 kb from the AVGR8 gene, encoding a putative transcription factor with typical ZNF and KRAB domains, in chromosomal region 13q12.11 (β = 0.14 SD, P = 3.5 × 10(-9)). The third new locus (rs6496932), on 15q25.3 (β = 0.13, P = 1.4 × 10(-8)), was within a wide linkage disequilibrium block extending into the 5' end of the AKAP13 gene, encoding a scaffold protein concerned with signal transduction from the cell surface. These associations offer mechanistic insights into the regulation of CCT and offer new candidate genes for susceptibility to common disorders in which CCT has been implicated, including primary open-angle glaucoma and keratoconus.

Digital image analysis of plus disease in retinopathy of prematurity

An accurate assessment of retinopathy of prematurity (ROP) is essential in ensuring correct and timely treatment of this potentially blinding condition. Current modes of assessment are based upon clinical grading by expert examination of retinal changes. However, this may be subjective, unreliable and difficult and there has been significant interest in alternative means of measurement. These have been made possible through technological advancements in image capture and analysis as well as progress in clinical research, highlighting the specific importance of plus disease in ROP. Progress in these two fields has highlighted the potential for digital image analysis of plus disease to be used as an objective, reliable and valid measurement of ROP. The potential for clinical and scientific advancement through this method is argued and demonstrated in this article. Along with the potential benefits, there are significant challenges such as in image capture, segmentation, measurement of vessel width and tortuosity; these are also addressed. After discussing and explaining the challenges involved, the research articles addressing digital image analysis of ROP are critically reviewed. Benefits and limitations of the currently published techniques for digital ROP assessment are discussed with particular reference to the validity and reliability of outcome measures. Finally, the general limitations of current methods of analysis are discussed and more diverse potential areas of development are discussed.

Incidence of retinopathy of prematurity in Lothian, Scotland, from 1990 to 2004

BACKGROUND

To report the trends in incidence of retinopathy of prematurity (ROP) within Lothian, a geographically defined region in southeast Scotland over a 15-year period from 1990 to 2004.

METHODS

This was a prospective observational study of all infants born with gestational age <32 weeks and/or birth weight <1500 g who were born to mothers resident in Lothian between 1 January 1990 and 31 December 2004. Eligible infants underwent eye screening by two experienced paediatric ophthalmologists (BF and EW). Lothian population data were obtained from the Scottish Health Service. The trends in survival rates, incidence and treatment of ROP were analysed from 1990 to 1994, 1995 to 1999 and 2000 to 2004.

RESULTS

Lothian population data showed a steady decline in the number of live births from 1990 to 2004. The proportion of babies born with birth weight <1500 g and/or gestational age <32 weeks remained constant (p = 0.271 using chi(2) test), although the proportion of these babies surviving to 42 weeks corrected gestation increased from 1990 to 2004 (p<0.001 using chi(2) test for trend). There was a statistically significant linear trend towards a reduction in the number of babies undergoing treatment for ROP throughout the study period (p<0.01 using chi(2) test for trend). A reduction in the incidence of any degree of ROP and severe (stage 3 or greater) ROP was also observed although this did not reach statistical significance.

CONCLUSIONS

There was a significant increase in survival of infants with birth weight <1500 g and/or gestational age <32 weeks together with a significant reduction in the number of infants treated for ROP in the Lothian region of southeast Scotland from 1990 to 2004.

Amniotic membrane grafting for conjunctival and lid surface disease in the acute phase of toxic epidermal necrolysis

Toxic epidermal necrolysis (TEN) is a severe form of Stevens-Johnson syndrome, characterized by extensive sloughing of mucous membranes and skin. It is associated with mortality rates of up to 70% and significant ocular morbidity in long-term survivors. We present a case of TEN with severe bilateral ocular involvement in whom we successfully used amniotic membrane grafts to treat the ocular surface during the acute phase of the disease.

Low oxygen exposure does not cause pulmonary injury in the newborn rat

BACKGROUND

Two recent studies have suggested that low levels of supplemental inspired oxygen may cause lung injury in preterm infants.

AIMS

To assess lung injury of newborn rats exposed to 14 days of low-level variation of oxygen.

STUDY DESIGN

Four groups were compared with 12 animals per group and 4 lung sections per animal. These were, a control group raised in room air and three groups raised in levels of inspired oxygen fluctuating around the following mean values: group Lo (mean FiO(2) 0.179), group N (mean FiO(2) 0.213), and group Hi (mean FiO(2) 0.247). The degree of oxygen variability was identical for each group. Lungs were inflated at 20 cm H(2)O, fixed and stained with H and E and Millers Elastin.

SUBJECTS

Sprague Dawley albino newborn rats.

OUTCOME MEASURES

Random alveolar areas were studied and analysed using imaging software to assess total amount of tissue and elastin, number of secondary septa, and mean linear intercept.

RESULTS

There were no significant differences between the three experimental oxygen groups and the control group in terms of lung/body weight ratio and the measured markers of lung development.

CONCLUSION

We conclude that low-level oxygen supplementation during early lung development does not affect alveolar development in the newborn rat.

Bilateral fourth-nerve palsy occurring after shaking injury in infancy

The shaken baby syndrome is a serious form of child abuse that typically results in serious short- and long-term neurological sequelae. Isolated cranial nerve palsies have been reported after shaking injuries in infants. We report a child with bilateral fourth cranial nerve palsy that developed after a shaking injury.

National study of microphthalmia, anophthalmia, and coloboma (MAC) in Scotland: investigation of genetic aetiology

We report an epidemiological and genetic study attempting complete ascertainment of subjects with microphthalmia, anophthalmia, and coloboma (MAC) born in Scotland during a 16 year period beginning on 1 January 1981. A total of 198 cases were confirmed giving a minimum live birth prevalence of 19 per 100 000. One hundred and twenty-two MAC cases (61.6%) from 115 different families were clinically examined and detailed pregnancy, medical, and family histories obtained. A simple, rational, and apparently robust classification of the eye phenotype was developed based on the presence or absence of a defect in closure of the optic (choroidal) fissure. A total of 85/122 (69.7%) of cases had optic fissure closure defects (OFCD), 12/122 (9.8%) had non-OFCD, and 25/122 (20.5%) had defects that were unclassifiable owing to the severity of the corneal or anterior chamber abnormality. Segregation analysis assuming single and multiple incomplete ascertainment, respectively, returned a sib recurrence risk of 6% and 10% in the whole group and 8.1% and 13.3% in the OFCD subgroup. Significant recurrence risks were found in both unilateral and bilateral disease. In four families, one parent had an OFCD, two of which were new diagnoses in asymptomatic subjects. All recurrences in first degree relatives occurred in the OFCD group with a single first cousin recurrence seen in the non-OFCD group. A total of 84/122 of the MAC cases were screened for mutations in the coding regions of PAX6, CHX10, and SIX3. No pathogenic mutations were identified in the OFCD cases. A single PAX6 homeodomain missense mutation was identified in a subject with partial aniridia that had been initially misclassified as coloboma.

A novel model of retinopathy of prematurity simulating preterm oxygen variability in the rat

PURPOSE

To examine changes in the retinal vasculature of rat pups after 14 days of minute-by-minute small variations in oxygen.

METHODS

Arterial oxygen data from a preterm infant who developed severe retinopathy of prematurity (ROP) was translated to equivalent values for the rat. Newborn rat pups were raised for 14 days in a cage in which a computer controlled the atmosphere to mimic the fluctuating oxygen profile (group V). Positive controls (P) of 12-hour cycles of 80% and 21% were run concurrently, as were room air controls (C). All were killed at day 14.

RESULTS

Groups V and P had significantly larger avascular retinal areas than C [median, interquartile range (IQR) 1.7%, 0-7.9%; 10%, 8.1-13%; 0%, 0-0%, respectively; each group n = 30]. Group P had a higher capillary branch count than C (median, IQR: 310/mm(2); 253-311 mm(2); versus 277/mm(2), 272-364/mm(2), respectively), but this was not significant using a multilevel analysis. Group V had significantly reduced capillary counts compared with C (median, 261/mm(2); IQR, 215-290/mm(2); P < 0.05 multilevel analysis). No neovascularization was seen in any group, though abnormal terminal vessels were seen at the avascular/vascular retina interface in 73% of rats in group P and 21% of rats in group V. In situ hybridization on serial sections demonstrated VEGF in the inner nuclear layer of the retina in P and V, whereas C showed trace levels only.

CONCLUSIONS

The vaso-obliterative stage of ROP can be induced in rats using clinically relevant oxygen levels.

Intensified physiotherapy improves fitness to fly in cystic fibrosis patients

OBJECTIVES

The life expectancy for patients with cystic fibrosis has risen constantly within the last 10 years to an average age over 20 years in western countries. However, most of these patients are partially respiratory insufficient. Frequently their physicians must decide whether it is acceptable to expose them to reduced air pressure on board of an aeroplane during long distance flights or how their fitness to fly can be improved prior to their annual vacation. We investigated the effect of intensified daily physiotherapy -carried out during a four weeks stay on Gran Canaria, Spain- on lung-function parameters, oxygen saturation and saliva neopterin as marker for ongoing inflammation in the respiratory tract.

METHODS

10 out of 12 patients (age 19 34 years, mean 28.6 years) were investigated two weeks prior and two weeks after their trip to the Canaries, Spain. Lung function on ground level and during flights to and from the island, oxygen saturation and saliva-flow adjusted neopterin in saliva were measured.

RESULTS

Over the entire group vital capacity (VC) improved significantly from 2.89 l (range 1.37 3.95) to 3.36 l (range 1.23 5.24). Intrathoracic gas volume as a sign for pulmonary hyperinflation- declined slightly from 3.79 l (range 2.06 6.17) to 3.48 l (range 2. 18 5.85). The oxygen saturation increased from 89.5% (range 79 - 92%) during the flight to the Canaries to 94% (range 82 - 96%) during the return flight. Saliva neopterin dropped from 0.8 pmol/min. (range 0.2 6.8 pmol/min) to 0.6 ( range 0.1 2.6 pmol/min) pointing to diminished inflammation in the respiratory tract.

CONCLUSION

Our results indicate that fitness to fly can be improved by intense physiotherapy as shown by improvement of vital capacity and oxygen saturation during flight. The influence of an additional climate change on the improvement of lung function in CF-patients needs further evaluation.

Blood gas-analyses in patients with cystic fibrosis to estimate hypoxemia during exposure to high altitudes in a hypobaric-chamber

OBJECTIVES

Patients with cystic fibrosis (CF) represent a special risk for commercial airlines. Even on ground conditions the oxygen partial pressure (paO subset2) of these patients is partially clearly reduced. The reduced air pressure on board of an airplane can cause a drop of the paO subset2 to a critical point (below 50 mmHg) during a flight. Therefore, medical assistance or at least oxygen-supply over a longer time period could be necessary. Aim of this study was to investigate reaction and clinical outcome of patients with CF during a hypobaric-chamber-flight at altitudes of 2. 000 and 3.000 m to appraise their risk for a flight-trip.

METHODS

10 CF-patients (age 19-35 years, mean age 30 y) were investigated in a hypobaric chamber prior to an already booked flight-trip to the Baleares (Spain). Lung-function, oxygen saturation (SO subset2) and paO subset2 by pressure adjusted blood gas analysis were measured on ground level, at 2.000 m and 3.000 m pressure-altitude.

RESULTS

Forced expiratory vital capacity (FVC) over the entire group was 2. 9 l (range 1.4 to 4.0 l), forced expiratory 1-second volume (FEV subset1) 2.08 l/sec (range: 1.22 to 3.61 l/sec). Values dropped slightly at 3.000 m chamber altitude (VC=2.7 l, FEV subset1=1.95 l/sec). SO subset2 decreased from 95 % on ground to 89% at 2.000 m and 86 % at 3.000 m chamber altitude. paO2 decreased from 79.5 mmHg at ground level to 60 mmHg at 2000m and 45.5 mmHg at 3.000 m. Only one patient with a paO subset2 of 52 mmHg didn t fall below the critical flight limit of 50 mmHg. No patient felt below a paO subset2 of 40 mmHg. No patient experienced dyspnea during the chamber flight. Two patients without subjective symptoms before the chamber flight developed mild ear blocks during descent presumably due to swollen polyps. Complaints improved quickly by applying decongestant nose-spray. -

CONCLUSION

The results of the chamber flights indicate that chronically adapted adult lung disease patients without accompanying heart disease and a paO subset2 of > 40 mmHg during flight can anticipate a safe flight trip. These results could be confirmed by the consecutive flight trip to Spain.

Severe thyroid eye disease associated with primary hypothyroidism and thyroid-associated dermopathy

Four unusual cases of patients are described with severe thyroid eye disease (TED) who presented with primary hypothyroidism and thyroid-associated dermopathy (TAD). All four patients had moderate or severe TED and elevated circulating thyrotropin (TSH) receptor antibodies.

Comparison of the efficacy of diclofenac and betamethasone following strabismus surgery

AIMS

To compare the relative antiinflammatory potency and safety of topical diclofenac-gentamicin with betamethasone-neomycin following strabismus surgery.

METHODS

A single centre, single observer, prospective, randomised, and double masked clinical trial of 25 children undergoing bilateral symmetrical horizontal strabismus surgery was carried out. One eye received diclofenac-gentamicin and the contralateral eye received betamethasone-neomycin; both treatments were instilled four times a day for 4 weeks postoperatively. Ocular inflammation was assessed at 1 and 4 weeks postoperatively, objectively by comparison with a photographic chart and subjectively by questionnaire.

RESULTS

There was no statistically significant difference in the rate of resolution of the inflammatory response between each group at both visits.

CONCLUSION

Diclofenac appears to be as effective as betamethasone in controlling postoperative inflammation following strabismus surgery and may offer a safer alternative to the use of topical steroids.

An ultrastructural investigation of an early manifestation of the posterior polymorphous dystrophy of the cornea

BACKGROUND

Posterior polymorphous dystrophy of the cornea is an uncommon, but well-recognized, congenital disease affecting Descemet's membrane and endothelium. Visual impairment usually is minimal and slowly progressive. Edema develops in a small number of patients, necessitating a corneal graft in middle age. An early manifestation of posterior polymorphous dystrophy with corneal edema present at birth or soon thereafter is extremely rare; only a few ultrastructural reports are available.

METHODS

The corneal button of a 5-month-old baby with posterior polymorphous dystrophy was examined by conventional light and electron microscopy.

FINDINGS

The anterior banded zone of Descemet's membrane was thinned (2 microns) in the axial part of the cornea, contained defects in the paraxial part, and was absent at the periphery. Where present, the anterior banded zone was lined posteriorly by a fibrocellular layer (containing fibroblast-like spindle cells and striated collagen fibrils) and a fibrillar layer forming an abnormal posterior collagenous layer. This layer was lined posteriorly by degenerate overlapping endothelial cells, which also were in apposition to the stroma in regions with an absent anterior banded zone. The defects in Descemet's membrane were used by the abnormal keratocytes to migrate between the anterior banded zone and the posterior collagenous layer. At the periphery, a multilayer of spindle cells was present behind the stroma.

CONCLUSIONS

Failure to produce a continuous anterior banded zone indicates an onset of the disease before the twelfth week of gestation. It appears that, in posterior polymorphous dystrophy, there is a mosaic of better preserved and dystrophic endothelial cells and that the presence or absence of the normal components of Descemet's membrane is determined by the proportion of dystrophic cells in the endothelial cell population.

Cryotherapy for retinopathy of prematurity in a regional neonatal intensive care unit

Ninety-six low birth-weight premature infants at risk of retinopathy of prematurity (ROP) were screened over a 25-month period, yielding 30 eyes of 15 infants with 'treatable' disease. The response and complications of cryotherapy were prospectively evaluated in these infants over a 3-24-month period. Six eyes of three infants progressed to cicatricial disease despite treatment. One infant developed angle closure glaucoma but neither eye showed cicatricial disease. In 24 eyes of 12 infants regression of active ROP was observed after treatment. The local and systemic complications associated with cryotherapy are discussed.