Welcome to the Ophthalmology Journal News page! This page will showcase the latest news from the world of Ophthalmology, as published by The British Journal of Ophthalmology (BMJ).
For the British Ophthalmology Journal Archives, please visit http://bjo.bmj.com/ .
These news items are mainly specific study results that are relevant to the layman.
We have also added another news page with more ‘general’ Opthalmogy news here: Opthamologist News.
Furthermore, we have added a page with general news articles about Eye Health here: Eye Problems Articles , which is a good read for both patients and Ophthalmologists alike.
Ophthalmology Journal News:
The rare mitochondrial DNA (mtDNA) variant m.8340G>A has been previously reported in the literature in a single, sporadic case of mitochondrial myopathy. In this report, we aim to investigate the case of a 39-year-old male patient with sensorineural deafness who presented to the eye clinic with nyctalopia, retinal pigmentary changes and bilateral cortical cataracts.
The patient was examined clinically and investigated with autofluorescence, full-field electroretinography, electro-oculogram and dark adaptometry. Sequencing of the mitochondrial genome in blood and muscle tissue was followed by histochemical and biochemical analyses together with single fibre studies of a muscle biopsy to confirm a mitochondrial aetiology.
Electrophysiology, colour testing and dark adaptometry showed significant photoreceptor dysfunction with macular involvement. Sequencing the complete mitochondrial genome revealed a rare mitochondrial tRNALys (MTTK) gene variant—m.8340G>A—which was heteroplasmic in blood (11%) and skeletal muscle (65%) and cosegregated with cytochrome c oxidase-deficient fibres in single-fibre studies.
We confirm the pathogenicity of the rare mitochondrial m.8340G>A variant the basis of single-fibre segregation studies and its association with an expanded clinical phenotype. Our case expands the phenotypic spectrum of diseases associated with mitochondrial tRNA point mutations, highlighting the importance of considering a mitochondrial diagnosis in similar cases presenting to the eye clinic and the importance of further genetic testing if standard mutational analysis does not yield a result.
This study evaluates ocular biometrics and aqueous humour dynamics (AHD) in healthy Chinese volunteers to determine how the various ocular parameters interact to maintain physiological intraocular pressure (IOP) at all ages.
Sixty-nine volunteers enrolled in this cross-sectional study and were categorised into young (20–30 years) and old (≥50 years) groups. Measurements included IOP, ocular biometrics and AHD. Data were analysed using mixed model with random sampling to account for both eyes from the same individual. Spearman’s rank correlation with bootstrap resampling was used to find associations between parameters.
Compared with young subjects, old subjects had significantly (p<0.05) thinner corneas (CCT; 549.7±5.7 vs 530.6±5.3 µm; mean±SEM), shallower anterior chambers (3.14±0.05 vs 2.37±0.05 mm) and slower aqueous flow (Fa; 3.0±0.1 vs 2.7±0.1 µL/min). Uveoscleral outflow slowed (Fu; 1.0±0.2 vs 0.7±0.1) but not significantly. A positive linear association between IOP and episcleral venous pressure was found (young: R2=0.16; old: R2=0.08). Negative correlation between Fa and CCT (R2=0.06) and positive correlation between Fa and outflow facility (R2=0.08) was found in old participants.
In the healthy ageing Chinese eye, IOP remains unchanged, while Fa slows, which is counterbalanced by slowing of Fu. Aqueous humour exits the eye preferentially through the trabecular route at all ages. Ageing is also associated with shallowing of the anterior chamber and thinning of the cornea. A slower Fa with lower outflow facility supports existence of autoregulatory mechanisms.
Patients with rhegmatogenous retinal detachment (RRD) who develop postoperative proliferative vitreoretinopathy (PVR) have been found to have higher preoperative laser flare values than patients with RRD who do not develop this complication. Measurement of laser flare has therefore been proposed as an objective, rapid and non-invasive method for identifying high-risk patients. The purpose of our study was to validate the use of preoperative flare values as a predictor of PVR risk in two additional patient cohorts, and to confirm the sensitivity and specificity of this method for identifying high-risk patients.
We combined data from two independent prospective studies: centre 1 (120 patients) and centre 2 (194 patients). Preoperative aqueous humour flare was measured with a Kowa FM-500 Laser Flare Meter. PVR was defined as redetachment due to the formation of traction membranes that required reoperation within 6 months of initial surgery. Logistic regression and receiver operating characteristic analysis determined whether higher preoperative flare values were associated with an increased risk of postoperative PVR.
PVR redetachment developed in 21/314 patients (6.7%). Median flare values differed significantly between centres, therefore analyses were done separately. Logistic regression showed a small but statistically significant increase in odds with increasing flare only for centre 2 (OR 1.014; p=0.005). Areas under the receiver operating characteristic showed low sensitivity and specificity: centre 1, 0.634 (95% CI 0.440 to 0.829) and centre 2, 0.731 (95% CI 0.598 to 0.865).
Preoperative laser flare measurements are inaccurate in discriminating between those patients with RRD at high and low risk of developing PVR.
To evaluate how closely neuropathic-like ocular pain (NOP) symptoms align with a metric of central sensitisation (ie, the presence of persistent ocular pain after topical anaesthetic placement) in individuals with dry eye (DE) symptoms.
Cross-sectional study of 224 individuals with DE symptoms seen in the Miami Veterans Affairs eye clinic. An evaluation was performed consisting of questionnaires regarding DE symptoms, NOP descriptors and evoked pain sensitivity testing on the forehead and forearm, followed by a comprehensive ocular surface examination including corneal mechanical sensitivity testing. Subsequent analyses were performed to examine for differences between those with and without ocular pain after topical anaesthetic placement.
The mean age was 62 years with 91% being men. DE symptoms and NOP symptoms were higher in subjects with persistent ocular pain after anaesthesia. Most DE signs were not related to persistent pain, with the exception of meibum quality. Individuals with persistent ocular pain also demonstrated greater sensitivity to evoked pain at testing sites on the forehead and forearm. When examining receiver operator characteristic curves considering persistent pain as a gold standard for central sensitisation within the corneal pathway, intensity of ocular pain ratings, Ocular Surface Disease Index scores and sensitivity to light provided the most robust relationships, each with an area under the curve of 0.72.
Individuals with DE symptoms and persistent ocular pain after topical proparacaine (a marker of central sensitisation to pain) more frequently report NOP-like symptoms and demonstrate increased sensitivity to evoked pain.
The aim of this study was to map out the developmental curve of the orbital volume of Chinese children aged 1–15 years.
CT scanning was performed on 109 children and the orbital volume, interlateral orbital rim distance (IORD), and extent of exophthalmos were measured on the CT images and plotted against age.
The development of the orbit structure followed a biphasic pattern. The first growth phase was before 3 years and the second growth phase was between 7 years and 12 years of age. The growth speed in the first phase was about 3 times that of the second one (first vs second phase: 2.28 cm3/year vs 0.67 cm3/year for orbital volume, 5.01 mm/year vs 1.57 mm/year for IORD, 1.29 mm/year vs 0.42 mm/year for the exophthalmos). During development, there was no significant difference between the left and right orbits. There was no significant difference between boys and girls before 12 years of age. However, after 12 years of age, boys had significantly larger orbital volumes (22.16±2.28 cm3/year vs 18.57±1.16 cm3/year, p<0.001) and a greater IORD (96.29±3.18 mm/year vs 91.00±4.54 mm/year, p<0.001) than girls.
In Chinese children, the development of orbital volume follows a biphasic pattern and a sex difference becomes significant after the age of 12 years.
To assess peripapillary perfused capillary density (PCD) in primary open-angle glaucoma (POAG) across stage of disease.
In this observational, cross-sectional study, 60 eyes with varying stages of POAG and 24 control eyes were imaged on a spectral domain optical coherence tomography angiography system (AngioVue, Optovue, Fremont, California, USA) generating images centred on the optic nerve head. Major blood vessels were removed using custom automated software. PCD was calculated as a percentage as the ratio of pixels associated with perfused capillaries to the total number of pixels in the corresponding region-of-interest (ROI). Analysis of covariance was used to compare PCD among the subject groups and control for possible covariates. Area under the receiver operating characteristic curve (AROC) and sensitivity at 95% specificity were calculated to assess the capability of PCD to distinguish mild glaucoma from control. The Pearson's product-moment correlation coefficient was used to assess correlations between PCD and circumpapillary retinal nerve fibre layer thickness (cpRNFLT) and visual field mean deviation (MD).
PCD demonstrated a progressive stepwise decrease from control eyes throughout worsening POAG stage at all ROIs. PCD demonstrated AROC and sensitivity values comparable to cpRNFLT and visual field parameters and exhibited significant correlations with cpRNFLT and MD at all corresponding ROIs.
PCD displayed significant correlations with morphological and functional indices and exhibited diagnostic capabilities comparable to currently employed clinical variables. Our preliminary results suggest that PCD analysis may prove to be a useful tool in monitoring POAG across stage and identifying early POAG.
To identify differences in neuronal tissue from retinal and brain structures in children born small for gestational age (SGA) with no abnormality in neonatal brain ultrasonography and no previous neurological impairment, and to evaluate the relationship between retinal structure and brain changes in school-age children born SGA.
Two cohorts of children were recruited: 25 children born SGA and 25 children born with an appropriate birth weight according to gestational age. All the children underwent an ophthalmic examination, which included retinal imaging using spectral-domain optical coherence tomography, and a brain MRI. MRI images were automatically segmented and global and regional brain volumes were obtained.
Although visual function did not differ between both groups, the complex ganglion cell and inner plexiform layers (GCL-IPL) was thinner in SGA children. Total intracranial volume, and global grey and white matter volumes in brain and cerebellum were correlated with birthweight centile, as were certain regional volumes (temporal and parietal lobes, hippocampus and putamen). Abnormal GCL-IPL measurements accurately identified SGA children with the most severe grey and white matter changes in the brain.
SGA children, both preterm and term born, showed evidence of structural abnormalities in the retina, which may be an accurate and non-invasive biomarker of neuronal damage in brain tissue.
To evaluate the efficacy of topical tacrloimus eye drops in the treatment of keratitis associated with autoimmune polyglandular syndrome (APS)-1.
This is a retrospective review of 10 patients with APS-1. The patients were treated with topical tacrolimus 0.01% solution at The Eye Center, between 1 March 2012 and 30 April 2016. The outcome measures included improvement in visual acuity, photophobia and keratitis following treatment. Clinical assessment was carried out before, during and on the last visit following initiation of therapy.
A total of 10 patients were included. There were five male and five female patients. The mean age was 11 years with age range of 3–42 years. The mean duration of treatment with topical tacrolimus was 26 months (range 8–46 months). There was improvement of photophobia in 7 out of 10 patients following therapy with topical tacrolimus. In three patients, the photophobia was persistent. There was no clinically detectable improvement in the severity of keratitis in all patients. The mean best corrected visual acuity was 0.1 before and following therapy.
Topical tacrolimus is effective in reducing the photophobia in patients with APS-1-associated keratitis, but showed no effects on the severity of keratitis.
To explore any relationship between the markers of early retinal neuronal damage and peripheral diabetic neuropathy in subjects with no diabetic retinopathy (DR).
A cross-sectional study in which type 2 diabetic subjects (n=743) without DR were studied. Visual functions including visual acuity, contrast sensitivity, colour vision, retinal sensitivity using microperimeter and retinal thicknesses by spectral domain optical coherence tomography were measured. Vibration perception thresholds of greater than or equal to 20 µV, measured by sensitometer using a biothesiometer probe, were defined as having peripheral diabetic neuropathy. Statistical analyses were performed using independent t-test, multivariate logistic regression and Pearson's correlation.
Of 743 subjects who had no DR, 24.9% had diabetic neuropathy. Independent comparisons among subjects who had diabetic neuropathy compared with those who did not showed statistically significant retinal nerve fibre layer thinning (p=0.01), reduced contrast sensitivity (p=0.0001), reduced retinal sensitivity (p=0.03), impaired colour vision (p=0.04) and reduced visual acuity (p=0.0001). Multivariate analysis showed significant association between the mean retinal sensitivity (measured using a microperimeter) and diabetic neuropathy (adjusted OR (95% CI): 0.76 (0.60 to 0.95), p=0.01).
Significant association of neuroretinal dysfunction with the presence of diabetic neuropathy was noted among subjects with no DR.
To evaluate the efficacy of Fourier domain-optical coherence tomography (FD-OCT) in imaging and quantifying the limbal palisades of Vogt and to correlate these images with histological findings.
The superior and inferior limbal region of both eyes of 50 healthy volunteers were imaged by FD-OCT. Images were processed and analysed using Matlab software. In vitro immunofluorescent staining of a cadaveric donor limbus was analysed to correlate the presence of stem cells in the visualised structures.
FD-OCT could successfully visualise limbal crypts and the palisades of Vogt in the limbus region. Fluorescent labelling confirmed the presence of stem cells in these structures. The mean palisade ridge width (PR) and the mean interpalisade epithelial rete peg width (ERP) were both of the order of 72 μm, leading to a palisade density (PD) of about 7.4 palisades/mm. A significant difference in PR, ERP and PD was seen between the inferior and superior sides of the right eye and the superior sides of the left and right eye(p<0.05.). A significant influence of iris colour on parameters PR, ERP and PD was found, and of age on PD and ERP (p<0.05).
In vivo OCT imaging is a safe and effective modality to image the limbus and can be used to visualise the palisades of Vogt. Image processing using Matlab software enabled quantification and density calculation of imaged limbal palisades of Vogt. This technique may enhance targeted limbal biopsies for transplantation.
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