General relativistic orbital decay in a seven-minute-orbital-period eclipsing binary system.

General relativity1 predicts that short-orbital-period binaries emit considerable amounts of gravitational radiation. The upcoming Laser Interferometer Space Antenna2 (LISA) is expected to detect tens of thousands of such systems3 but few have been identified4, of which only one5 is eclipsing-the double-white-dwarf binary SDSS J065133.338+284423.37, which has an orbital period of 12.75 minutes. Here we report the discovery of an eclipsing double-white-dwarf binary system, ZTF J153932.16+502738.8, with an orbital period of 6.91 minutes. This system has an orbit so compact that the entire binary could fit within the diameter of the planet Saturn. The system exhibits a deep eclipse, and a double-lined spectroscopic nature. We see rapid orbital decay, consistent with that expected from general relativity. ZTF J153932.16+502738.8 is a strong source of gravitational radiation close to the peak of LISA's sensitivity, and we expect it to be detected within the first week of LISA observations, once LISA launches in approximately 2034.

VERTICAL AND HORIZONTAL METAMORPHOPSIA ONE YEAR AFTER SURGERY FOR MACULAR HOLES ≤ 500 µ m WITH AND WITHOUT INVERTED INTERNAL LIMITING MEMBRANE FLAP.

PURPOSE: To investigate the effect of an inverted internal limiting membrane flap (IF) and other factors on metamorphopsia after macular hole surgery. METHODS: Prospective case series of patients undergoing pars plana vitrectomy with gas tamponade, with either conventional internal limiting membrane peeling (CP) or an IF, for primary idiopathic macular holes ≤ 500 µ m. Vertical and horizontal metamorphopsia were measured as M-scores (degrees) using M-charts preoperatively and at 2, 6, and 12 months postoperatively. RESULTS: Fifty-three eyes of 53 patients were included of whom 27 underwent CP and 26 were treated with an IF. After macular hole surgery, all patients were pseudophakic. Vertical and horizontal metamorphopsia improved from 1.08 (±0.51) and 0.98 (±0.70) preoperatively to 0.58 (±0.37) and 0.45 (±0.36) at 2 months ( P < 0.01), with no further significant improvement at 6 months (0.39 [±0.31], P = 0.07 and 0.31 [±0.28], P = 0.18) or at 12 months (0.37 [±0.30], P = 0.72 and 0.28 [±0.28], P = 0.99). There was no significant difference in the mean vertical and horizontal metamorphopsia between patients with CP and with an IF at 2 months ( P = 0.063, P = 0.10), 6 months ( P = 0.25, P = 0.16), or 12 months ( P = 0.62, P = 0.22). Preoperative vertical M-score improved at 12 months after macular hole surgery by 61% and 64% in the CP and IF groups, respectively ( P = 0.84), and the horizontal M-score by 65% and 71%, respectively ( P = 0.98). CONCLUSION: The use of an IF has no evident bearing on the degree of postoperative metamorphopsia 12 months after surgical repair of macular holes ≤ 500 µ m.

INFLUENCE OF PREOPERATIVE POSTURING ON SUBFOVEAL FLUID HEIGHT IN MACULA-OFF RETINAL DETACHMENTS.

PURPOSE: To evaluate the effect of preoperative posturing on subfoveal fluid height (SFFH) in macula-off retinal detachment. METHODS: A prospective study including patients with macula-off retinal detachment with SFFH measurable on optical coherence tomography (OCT) and duration of loss of central vision (LCV) ≤ 7 days. Linear OCT volume scans were performed at baseline, after 1 minute, 1 hour, 4 hours, and on the next morning. For the first hour, all patients remained in an upright position. Patients were then either instructed to posture until the surgery according to the location of the primary retinal break (posturing group) or were not given any instructions (control group). RESULTS: Twenty-four patients were included in the posturing group and 11 patients in the control group. There was no significant change in SFFH between baseline, 1 minute, 1 hour, and 4 hours. The mean SFFH in the control group increased by 243 µ m from 624 (±268) µ m at baseline to 867 (±303) µ m the next morning ( P < 0.01) but decreased in the posturing group by 150 µ m from 728 (±416) to 578 (±445) µ m ( P = 0.03). There was a significant association of the SFFH the next morning with posturing ( P < 0.01) and SFFH at baseline ( P < 0.01), but not with location of primary break ( P = 0.20). The change in SFFH from baseline to the next morning was significantly associated with posturing and primary break location ( P < 0.01), but not with SFFH at baseline ( P = 0.21). CONCLUSION: Preoperative posturing is an effective measure to prevent progression of macular detachment in macula-off retinal detachment.

Impact of fluoroquinolones and aminoglycosides on P. aeruginosa virulence factor production and cytotoxicity.

The opportunistic pathogen Pseudomonas aeruginosa is one of leading causes of disability and mortality worldwide and the world health organisation has listed it with the highest priority for the need of new antimicrobial therapies. P. aeruginosa strains responsible for the poorest clinical outcomes express either ExoS or ExoU, which are injected into target host cells via the type III secretion system (T3SS). ExoS is a bifunctional cytotoxin that promotes intracellular survival of invasive P. aeruginosa by preventing targeting of the bacteria to acidified intracellular compartments. ExoU is a phospholipase which causes destruction of host cell plasma membranes, leading to acute tissue damage and bacterial dissemination. Fluoroquinolones are usually employed as a first line of therapy as they have been shown to be more active against P. aeruginosa in vitrothan other antimicrobial classes. Their overuse over the past decade, however, has resulted in the emergence of antibiotic resistance. In certain clinical situations, aminoglycosides have been shown to be more effective then fluoroquinolones, despite their reduced potency towards P. aeruginosa in vitro. In this study, we evaluated the effects of fluoroquinolones (moxifloxacin and ciprofloxacin) and aminoglycosides (tobramycin and gentamycin) on T3SS expression and toxicity, in corneal epithelial cell infection models. We discovered that tobramycin disrupted T3SS expression and reduced both ExoS and ExoU mediated cytotoxicity, protecting infected HCE-t cells at concentrations below the minimal inhibitory concentration (MIC). The fluoroquinolones moxifloxacin and ciprofloxacin, however, up-regulated the T3SS and did not inhibit and may have increased the cytotoxic effects of ExoS and ExoU.

Artificial intelligence utilising corneal confocal microscopy for the diagnosis of peripheral neuropathy in diabetes mellitus and prediabetes.

AIMS/HYPOTHESIS: We aimed to develop an artificial intelligence (AI)-based deep learning algorithm (DLA) applying attribution methods without image segmentation to corneal confocal microscopy images and to accurately classify peripheral neuropathy (or lack of). METHODS: The AI-based DLA utilised convolutional neural networks with data augmentation to increase the algorithm's generalisability. The algorithm was trained using a high-end graphics processor for 300 epochs on 329 corneal nerve images and tested on 40 images (1 image/participant). Participants consisted of healthy volunteer (HV) participants (n = 90) and participants with type 1 diabetes (n = 88), type 2 diabetes (n = 141) and prediabetes (n = 50) (defined as impaired fasting glucose, impaired glucose tolerance or a combination of both), and were classified into HV, those without neuropathy (PN-) (n = 149) and those with neuropathy (PN+) (n = 130). For the AI-based DLA, a modified residual neural network called ResNet-50 was developed and used to extract features from images and perform classification. The algorithm was tested on 40 participants (15 HV, 13 PN-, 12 PN+). Attribution methods gradient-weighted class activation mapping (Grad-CAM), Guided Grad-CAM and occlusion sensitivity displayed the areas within the image that had the greatest impact on the decision of the algorithm. RESULTS: The results were as follows: HV: recall of 1.0 (95% CI 1.0, 1.0), precision of 0.83 (95% CI 0.65, 1.0), F1-score of 0.91 (95% CI 0.79, 1.0); PN-: recall of 0.85 (95% CI 0.62, 1.0), precision of 0.92 (95% CI 0.73, 1.0), F1-score of 0.88 (95% CI 0.71, 1.0); PN+: recall of 0.83 (95% CI 0.58, 1.0), precision of 1.0 (95% CI 1.0, 1.0), F1-score of 0.91 (95% CI 0.74, 1.0). The features displayed by the attribution methods demonstrated more corneal nerves in HV, a reduction in corneal nerves for PN- and an absence of corneal nerves for PN+ images. CONCLUSIONS/INTERPRETATION: We demonstrate promising results in the rapid classification of peripheral neuropathy using a single corneal image. A large-scale multicentre validation study is required to assess the utility of AI-based DLA in screening and diagnostic programmes for diabetic neuropathy.

Anatomical and functional outcomes of pneumatic vitreolysis for treatment of vitreomacular traction with and without macular holes.

PURPOSE: To evaluate the outcome of pneumatic vitreolysis (PVL) for vitreomacular traction (VMT) with or without full thickness macular hole (MH) < 400 µm. METHODS: Forty-seven eyes of 47 patients were included who had undergone PVL for VMT with or without MH. Main outcome measures were release of VMT, MH closure, best-corrected visual acuity (BCVA) and adverse events. RESULTS: Thirty-three patients had isolated VMT and 14 patients VMT with a MH. Four weeks after PVL, the overall VMT release rate was 35/47 (74.5%): 25/37 (67.6%) in phakic and 10/10 (100%) in pseudophakic eyes (p = 0.03). Four of 14 MH (28.6%) were closed. Twenty-two of 47 (46.8%) eyes required a subsequent PPV: 12/33 (36.4%) in the VMT only group and 10/14 (71.4%) in the VMT with MH group. Mean BCVA improved from 0.48 (± 0.24) to 0.34 (± 0.23) logMAR at 6 months in patients with VMT alone (p < 0.001), and from 0.57 (± 0.27) to 0.41 (± 0.28) logMAR in patients with VMT and MH (p = 0.008). Adverse events included new formation of a large MH in 4/33 (12.1%) eyes, failure of MH closure in 10/14 (71.4%) eyes, progression of mean minimum linear diameter (MLD) MH size from baseline 139 (± 67) to 396 (± 130) µm (p < 0.001) and development of a retinal detachment in 4/47 (8.5%) eyes. CONCLUSION: While PVL leads to a high VMT release rate particularly in pseudophakic eyes, it is associated with a relatively high incidence of MH formation, MH size progression and retinal detachment.

A pipeline to evaluate inhibitors of the Pseudomonas aeruginosa exotoxin U.

Pseudomonas aeruginosa has recently been highlighted by the World Health Organisation (WHO) as a major threat with high priority for the development of new therapies. In severe P. aeruginosa infections, the phospholipase activity of the type 3 secretion system toxin, ExoU, induces lysis of target host cells and results in the poorest clinical outcomes. We have developed an integrated pipeline to evaluate small molecule inhibitors of ExoU in vitro and in cultured cell models, including a disease-relevant corneal epithelial (HCE-T) scratch and infection model using florescence microscopy and cell viability assays. Compounds Pseudolipasin A, compound A and compound B were effective in vitro inhibitors of ExoU and mitigated P. aeruginosa ExoU-dependent cytotoxicity after infection of HCE-T cells at concentrations as low as 0.5 µM. Addition of the antimicrobial moxifloxacin controlled bacterial load, allowing these assays to be extended from 6 h to 24 h. P. aeruginosa remained cytotoxic to HCE-T cells with moxifloxacin, present at the minimal inhibitory concentration for 24 h, but, when used in combination with either Pseudolipasin A, compound A or compound B, a greater amount of viable cells and scratch healing were observed. Thus, our pipeline provides evidence that ExoU inhibitors could be used in combination with certain antimicrobials as a novel means to treat infections due to ExoU producing P. aeruginosa, as well as the means to identify more potent ExoU inhibitors for future therapeutics.

Epithelial Cell-Derived Extracellular Vesicles Trigger the Differentiation of Two Epithelial Cell Lines.

Extracellular vesicles (EVs), specifically exosomes, carry a cell-type dependent cargo that is transported to the recipient cell and translated in the presence of a required machinery. Differences in the cargo carried by the corneal and conjunctival-derived EVs could be the agent that triggers the transdifferentiation of these two cell populations. Therefore, this study investigates the role of EVs in triggering the plasticity of corneal and conjunctival epithelial cells and identifies prospective miRNA and genes responsible for maintaining ocular surface homeostasis. The EVs were extracted from the conditioned media (after starving) of corneal epithelial (hTCEpi) and conjunctival (HCjE-Gi) cell lines using ultracentrifugation. HCjE-Gi cells were cultured with hTCEpi-derived EVs and vice-versa. The EVs were characterized as exosomes using Nanosight and Flow cytometry. KRT3 and KRT12 were used as associated corneal markers, whereas KRT7 and KRT13 were used as associated conjunctival markers with ΔNp63 as a differentiation marker. Shift of these markers was an indication of transdifferentiation. The cargo of the extracted exosomes from both the cell types was explored using next-generation sequencing. The hTCEpi-derived EVs induced conjunctival epithelial cells to express the corneal-associated markers KRT3 and KRT12, losing their conjunctival phenotype at both the mRNA and protein level. Simultaneously, HCjE-Gi-derived EVs induced corneal epithelial cells to express the conjunctival associated markers KRT7 and KRT13, losing their corneal phenotype. This process of differentiation was accompanied by an intermediate step of cell de-differentiation showed by up-regulation in the expression of epithelial stem cell marker ΔNp63, also shown on the ex vivo human cadaveric donor corneas. miRNA molecules (total of 11 including precursor and mature) with significant differences in their relative abundance between the two populations (p < 0.05) were found and investigated. miR-9-5p expression was higher in HCjE-Gi cells and HCjE-Gi-derived EVs when compared to hTCEpi cells and hTCEPi-derived EVs (p < 0.001). The results suggest that EVs released by the two cell types have the ability to influence the transdifferentiation of human conjunctival and corneal epithelial cells. miR-9-5p could have a role in stem cell homeostasis and cell differentiation via HES-1 gene.

FUNCTIONAL AND MORPHOLOGICAL OUTCOMES OF THE INVERTED INTERNAL LIMITING MEMBRANE FLAP TECHNIQUE IN SMALL-SIZED AND MEDIUM-SIZED MACULAR HOLES <400 µm.

PURPOSE: To assess the effect of an internal limiting membrane flap (IF) in macular hole surgery on the best-corrected visual acuity (BCVA) and integrity of the ellipsoid zone (EZ) and external limiting membrane. METHODS: Patients were included who had successful surgery for macular hole <400 µm with or without an IF. Main outcome measures were BCVA and restoration of the external limiting membrane and EZ at 12 months. RESULTS: Sixty patients were included, 36 with conventional peeling and 24 with an IF. The best-corrected visual acuity improved from 0.74 (±0.30) logarithm of the minimum angle of resolution (20/110 Snellen) to 0.26 (±0.20) (20/36 Snellen) in patients without and from 0.77 (±0.32) logarithm of the minimum angle of resolution (20/118 Snellen) to 0.18 (±0.12) (20/30 Snellen) in patients with an IF, respectively. There was no difference in the integrity of the EZ and external limiting membrane in patients with or without an IF at either 3 (P = 0.58, P = 0.20), 6 (P = 0.81, P = 0.10), or 12 months (P = 0.60, P = 0.20) or in the BCVA at 3 (P = 0.24), 6 (P = 0.18) and 12 months (P = 0.11). In the multivariable model, only preoperative BCVA (P < 0.01), EZ integrity (P = 0.001), and age (P < 0.01) were associated with the post-operative BCVA. CONCLUSION: In patients undergoing surgery for macular hole <400 µm, the use of an IF did not affect the BCVA or the integrity of the EZ and external limiting membrane.

Cost analysis of eye bank versus surgeon prepared endothelial grafts.

BACKGROUND: Selective lamellar corneal transplantation (keratoplasty) has overtaken full thickness penetrating keratoplasty as the graft choice for endothelial failure. Even more recently eye bank prepared tissues are becoming increasing popular as a way to reduce the risks of tissue loss and stress during endothelial keratoplasty preparation in the surgical theatre. This study compares costs between surgeon and eye bank prepared tissues for Descemet's stripping automated endothelial keratoplasty (DSAEK) and Descemet's membrane endothelial keratoplasty (DMEK). METHODS: Retrospective study conducted at the Royal Liverpool University Hospital including endothelial keratoplasties with a minimum of 6 months follow-up time. Cost analysis included surgical expenses, tissue acquisition fees, cost of patient's ward admission and out-patient expenses, including cost of re-bubbling procedures, costs of visits, anterior segment imaging and optometrist visits within the first 6 months follow-up. RESULTS: Ninety-eight eyes of 98 patients were included in the study of which 42 underwent DSAEK surgery and 56 DMEK surgery. Cost analysis of surgical expenses in the DSAEK group showed a significant difference between using surgeon prepared and eye bank prepared tissue (£3866 ± 296 and £4389 ± 360, respectively; p < 0.01) and the same was found in the DMEK group (£3682 ± 167 and £4162 ± 167 for surgeon prepared and eye bank prepared tissues, respectively; p < 0.01). Cost of out-patient visits did not differ significantly in either group. CONCLUSIONS: At the Royal Liverpool University Hospital, eye bank prepared tissues had higher surgical expenses compared to those prepared by the surgeon, while the post-operative care expenses were similar between the two groups.

An artificial intelligence-based deep learning algorithm for the diagnosis of diabetic neuropathy using corneal confocal microscopy: a development and validation study.

AIMS/HYPOTHESIS: Corneal confocal microscopy is a rapid non-invasive ophthalmic imaging technique that identifies peripheral and central neurodegenerative disease. Quantification of corneal sub-basal nerve plexus morphology, however, requires either time-consuming manual annotation or a less-sensitive automated image analysis approach. We aimed to develop and validate an artificial intelligence-based, deep learning algorithm for the quantification of nerve fibre properties relevant to the diagnosis of diabetic neuropathy and to compare it with a validated automated analysis program, ACCMetrics. METHODS: Our deep learning algorithm, which employs a convolutional neural network with data augmentation, was developed for the automated quantification of the corneal sub-basal nerve plexus for the diagnosis of diabetic neuropathy. The algorithm was trained using a high-end graphics processor unit on 1698 corneal confocal microscopy images; for external validation, it was further tested on 2137 images. The algorithm was developed to identify total nerve fibre length, branch points, tail points, number and length of nerve segments, and fractal numbers. Sensitivity analyses were undertaken to determine the AUC for ACCMetrics and our algorithm for the diagnosis of diabetic neuropathy. RESULTS: The intraclass correlation coefficients for our algorithm were superior to those for ACCMetrics for total corneal nerve fibre length (0.933 vs 0.825), mean length per segment (0.656 vs 0.325), number of branch points (0.891 vs 0.570), number of tail points (0.623 vs 0.257), number of nerve segments (0.878 vs 0.504) and fractals (0.927 vs 0.758). In addition, our proposed algorithm achieved an AUC of 0.83, specificity of 0.87 and sensitivity of 0.68 for the classification of participants without (n = 90) and with (n = 132) neuropathy (defined by the Toronto criteria). CONCLUSIONS/INTERPRETATION: These results demonstrated that our deep learning algorithm provides rapid and excellent localisation performance for the quantification of corneal nerve biomarkers. This model has potential for adoption into clinical screening programmes for diabetic neuropathy. DATA AVAILABILITY: The publicly shared cornea nerve dataset (dataset 1) is available at http://bioimlab.dei.unipd.it/Corneal%20Nerve%20Tortuosity%20Data%20Set.htm and http://bioimlab.dei.unipd.it/Corneal%20Nerve%20Data%20Set.htm.

En-face analysis of the human limbal lymphatic vasculature.

PURPOSE: To describe the location and morphometric characteristics of the human limbal lymphatic vasculature and its relation to the marginal corneal vascular arcades (MCA). METHODS: Ex vivo confocal microscopic (CM) imaging and immunofluorescence double staining for CD-31 and D2-40 of histological en-face sections using 12 preserved human cadaveric corneoscleral discs were performed, followed by a semi-automated morphometric analysis of the two-dimensional vascular network architecture. RESULTS: Ex vivo CM confirmed the presence of 2 distinct vascular networks. The haematic limbal vascular complex (HLVC) extended further into the cornea, forming typical MCAs. The lymphatic limbal vascular complex (LLVC) was peripheral from the termination of Bowman's layer and was also found to be peripheral to and deeper than the HLVC. LLVC and HLVC were significantly different with respect to vessel diameter, segment length and wall thickness. CONCLUSION: The lymphatic vasculature of the human corneoscleral limbal region displays specific morphometric features that allow its differentiation from haematic vessels using CM.

EFFECT OF INVERTED INTERNAL LIMITING MEMBRANE FLAP ON CLOSURE RATE, POSTOPERATIVE VISUAL ACUITY, AND RESTORATION OF OUTER RETINAL LAYERS IN PRIMARY IDIOPATHIC MACULAR HOLE SURGERY.

PURPOSE: To investigate the role of an internal limiting membrane (ILM) flap in macular hole (MH) surgery on closure rate, visual acuity, and integrity of the outer retinal layers. METHODS: Retrospective, nonrandomized interventional analysis in which 117 eyes of 117 patients were included who had undergone pars-plana vitrectomy (PPV) and gas tamponade for primary idiopathic MH >400 µm with either conventional ILM peeling or with inverted ILM flap technique at The Royal Liverpool University Hospital between January 2016 and April 2018. Main outcome measures were closure of MH, best-corrected visual acuity (BCVA) at 3, 6, and 12 months, and restoration of external limiting membrane and ellipsoid zone (EZ) using optical coherence tomography. RESULTS: Macular hole closure rate was significantly higher in patients with an ILM flap (67/68; 98.53%) than in those with conventional ILM peeling (43/49; 87.76%) (P = 0.02). Both groups showed significant improvements in their preoperative to postoperative BCVA at 3 months from 1.07 (0.43) logarithm of the minimum angle of resolution (logMAR) (20/235 Snellen) to 0.71 (0.34) logMAR (20/103 Snellen) (P <0.001), but there was no significant difference between the two groups (P = 0.45, P = 0.71). We found significant associations between postoperative BCVA and preoperative BCVA (P < 0.01) and the integrity of the EZ (P < 0.01). In 35 patients who had follow-up to 12 months, there was a significant improvement in BCVA between 3, 6, and 12 months from 0.73 (0.45) logMAR (20/107 Snellen) to 0.53 (0.24) logMAR (20/68 Snellen) and to 0.35 (0.18) logMAR (20/45 Snellen), respectively (P < 0.01). There was no significant difference at these time periods between the two groups (P = 0.62, P = 0.21, P = 0.31). The integrity of the EZ also improved significantly between 3, 6, and 12 months (P = 0.01), irrespective of the presence of an ILM flap (P = 0.58), but with a trend toward delay in restoration in those patients with an ILM flap. The improvement in BCVA at 12 months, taking into account the age of the patient, size and duration of the MH, presence of an ILM flap, and preoperative BCVA was dependent on the state of the EZ (P = 0.01). CONCLUSION: In patients undergoing primary pars-plana vitrectomy for MH >400 µm, the presence of an inverted ILM flap was associated with a significantly higher closure rate than a conventional ILM peeling. Best-corrected visual acuity showed a strong correlation with the integrity of the EZ and both improved significantly between 3, 6, and 12 months, irrespective of the presence of an ILM flap.

Evaluating Refractive Outcomes after Cataract Surgery.

PURPOSE: To compare methods for evaluating refractive outcomes after cataract surgery to detect outliers. DESIGN: Case series database study of the evaluation of diagnostic technology. PARTICIPANTS: Consecutive patients who had uneventful cataract operations over a 5-year period. METHODS: The intended and postoperative refractive outcome and differences between these were analyzed as a spherical equivalent, cylinder, and spherocylinder. The average keratometry and differences between steep and flat keratometric meridians were used to calculate the intended refractive error. MAIN OUTCOME MEASURES: Outliers were defined as patients for whom the difference between the intended and postoperative refractive errors was more than 3 standard deviations (SDs) away from the mean. RESULTS: A total of 9000 patients were included. Twelve patients had missing data and were excluded. The mean intended refractive outcome was -0.12+0.12×2 (95% lower confidence limit [LCL], -1.94+1.06×44; 95% upper confidence limit [UCL], +0.77+1.05×140). The actual postoperative refractive error was -0.30+0.47×6 (95% LCL, -2.36+1.31×36; 95% UCL, +1.00+1.18×148) with a difference from the intended of -0.18+0.35×7 (95% LCL, -1.91+1.22×38; 95% UCL, +0.75+1.09×145). Treating the components of the refractive error independently, outliers were observed in 82 eyes (0.91%) based on the sphere, 46 eyes (0.51%) based on the spherical equivalent, 115 eyes (1.28%) based on treating the cylinder as a scalar, and 76 eyes (0.85%) based on treating the cylinder as a vector. When the differences between the intended and postoperative refractive errors were calculated as a compound spherocylinder, outliers were observed for 233 eyes (2.59%). CONCLUSIONS: Treating the intended refractive outcome as a spherocylinder improves the precision for detecting clinically significant refractive outliers.

A Rare Case of Gestational Choriocarcinoma Presenting as Cornual Ectopic Pregnancy.

BACKGROUND: Choriocarcinoma associated with cornual pregnancy is extremely rare. To our knowledge, only three other cases have been reported in the literature. CASE: A 38-year-old woman was found to have a left cornual ectopic pregnancy on ultrasound after presenting with abdominal pain, irregular vaginal bleeding, and a positive pregnancy test. Laparoscopy confirmed the diagnosis and she underwent total abdominal hysterectomy. Three weeks later, she presented with vaginal bleeding. A solid ulcerating lesion was found arising from the vaginal wall and biopsy revealed metastatic gestational choriocarcinoma. CONCLUSION: Careful histopathological examination of the surgical specimen and diligent monitoring of ß-human chorionic gonadotropin to zero is crucial to prevent potentially missing this very malignant, but highly curable disease. Early systemic metastases are common and presentation can include bleeding from vaginal metastases.

Outcome of Descemet stripping automated endothelial keratoplasty in eyes with an Ahmed glaucoma valve.

PURPOSE: The purpose was to investigate the survival of Descemet stripping automated endothelial keratoplasty (DSAEK) in eyes with an Ahmed glaucoma valve (AGV). METHODS: The study had a retrospective case-series of patients with an AGV in the anterior chamber undergoing a DSAEK. Included in the analysis were graft size, number of previous operations, post-operative glaucoma medications, post-operative intraocular pressure (IOP) control, graft size and donor factors (age, endothelial cell density, and post-mortem time). A generalised linear model with binary logistic regression was used to test for an effect on graft survival at 1 year and 1.5 years. RESULTS: Fourteen eyes from 13 patients were included. The survival rate of the first DSAEK at 6, 12, 18, 24 and 30-months was 85%, 71%, 50%, 36% and 30%, respectively. The mean duration to graft failure was 12.9 ± 6.2 months. Five of the seven failed first grafts went on to have a repeat DSAEK. The mean follow-up in this subgroup was 30.7 ± 18.4 months. The survival rate of second DSAEK at 6, 12, 18 and 24 months was 100% (5/5), 100% (5/5), 75% (3/4) and 67% (2/3). Only one second DSAEK failed in the duration of the study and went on to receive a third DSAEK which failed at 18-months. The mean IOP within the first year was significantly lower for grafts that survived at 1 and 1.5 years (17.4 mmHg, 16.9 mmHg) than for grafts that failed (19.4 mmHg, 19.4 mmHg) (p = 0.04, p = 0.009). CONCLUSION: DSAEK is a viable alternative to PK to restore visual function in eyes with an AGV sited in the anterior chamber. IOP is an important risk factor for graft failure.

High resolution corneal and single pulse imaging with line field spectral domain optical coherence tomography.

We report the development of a Spectral Domain Line Field Optical Coherence Tomography (LF-OCT) system, using a broad bandwidth and spatial coherent Super-Continuum (SC) source. With conventional quasi-Continuous Wave (CW) setup we achieve axial resolutions up to 2.1 µm in air and 3D volume imaging speeds up to 213 kA-Scan/s. Furthermore, we report the use of a single SC pulse, of 2 ns duration, to temporally gate an OCT B-Scan image of 70 A-Scans. This is the equivalent of 35 GA-Scans/s. We apply the CW setup for high resolution imaging of the fine structures of a human cornea sample ex-vivo. The single pulse setup is applied to imaging of a coated pharmaceutical tablet. The fixed pattern noise due to spectral noise is removed by subtracting the median magnitude A-Scan. We also demonstrate that the Fourier phase can be used to remove aberration caused artefacts.

Intraoperative management of macroperforations of Descemet's membrane in deep anterior lamellar keratoplasty.

BACKGROUND: To describe a surgical approach for the completion of pre-descemetic deep anterior lamellar keratoplasty (pdDALK) in the presence of a macroperforation of Descemet's membrane (DM). METHODS: Using case notes, we recorded the details of the intra- and perioperative course of patients who underwent successful pdDALK in the presence of macroperforation. A literature search of pdDALK techniques available to the corneal surgeon in a similar scenario was undertaken. RESULTS: In two very different scenarios with intra- or preoperative perforation of DM, a centripetal layered lamellar dissection was performed and allowed completion of pdDALK with a residual recipient central stromal thickness of 36 and 115 µm and good visual outcome. CONCLUSION: Despite very different scenarios, a centripetal layered lamellar dissection offers an approach for the completion of pdDALK in the presence of a macroperforation.