Glutathione and a Pool of Metabolites Partly Related to Oxidative Stress Are Associated with Low and High Myopia in an Altered Bioenergetic Environment.

Oxidative stress forms part of the molecular basis contributing to the development and manifestation of myopia, a refractive error with associated pathology that is increasingly prevalent worldwide and that subsequently leads to an upsurge in degenerative visual impairment due to conditions that are especially associated with high myopia. The purpose of our study was to examine the interrelation of potential oxidative-stress-related metabolites found in the aqueous humor of high-myopic, low-myopic, and non-myopic patients within a clinical study. We conducted a cross-sectional study, selecting two sets of patients undergoing cataract surgery. The first set, which was used to analyze metabolites through an NMR assay, comprised 116 patients. A total of 59 metabolites were assigned and quantified. The PLS-DA score plot clearly showed a separation with minimal overlap between the HM and control samples. The PLS-DA model allowed us to determine 31 major metabolite differences in the aqueous humor of the study groups. Complementary statistical analysis of the data allowed us to determine six metabolites that presented significant differences among the experimental groups (p < 005). A significant number of these metabolites were discovered to have a direct or indirect connection to oxidative stress linked with conditions of myopic eyes. Notably, we identified metabolites associated with bioenergetic pathways and metabolites that have undergone methylation, along with choline and its derivatives. The second set consisted of 73 patients who underwent a glutathione assay. Here, we showed significant variations in both reduced and oxidized glutathione in aqueous humor among all patient groups (p < 0.01) for the first time. Axial length, refractive status, and complete ophthalmologic examination were also recorded, and interrelations among metabolic and clinical parameters were evaluated.

Recovery course of persistent posterior subretinal fluid after successful repair of rhegmatogenous retinal detachment.

PURPOSE: To investigate best corrected visual acuity (BCVA), subretinal fluid (SRF) absorption time or ellipsoid zone (EZ) restoration time and various variables in patients with persistent SRF after successful primary repair of rhegmatogenous retinal detachment (RRD). METHODS: This retrospective multicenter study allowed independent analysis of the healing pattern by two observers based on composite of serial cross-sectional macular optical coherence tomography (OCT) scans. Univariate and multivariate analyses were implemented. RESULTS: One hundred and three cases had persistent SRF after pars plana vitrectomy, scleral buckling, or pneumatic retinopexy. By univariate analysis, SRF resolution time correlated positively with the number of retinal breaks (p < 0.001) and with increased myopia (p = 0.011). Using multivariate analysis, final BCVA (log MAR) correlated positively with age, duration of RRD, initial BCVA (OR = 3.28; [95%CI = 1.44-7.47]; p = 0.015), and SRF resolution time (OR = 0.46 [95%CI 0.21-1.05]; p = 0.049). EZ restoration time was longer with increasing number of retinal tears (OR = 0.67; [95%CI 0.29-1.52]; p = 0.030), worse final BCVA, and presence of macula-off RRD (OR = 0.26; [95%CI 0.08-0.88]; p = 0.056). SRF resolution time correlated marginally with prone position. CONCLUSIONS: Residual posterior SRF is more common in eyes with multiple breaks or in myopic eyes. Final BCVA is better in younger subjects and in eyes with shorter duration of RRD. Persistent SRF is a self-limited disorder with a mean resolution of 11.2 months with good visual prognosis improving from a mean baseline logMAR of 1.08 to 0.25 at one year.

Recovery course of foveal microstructure in the nonsurgical resolution of full-thickness macular hole.

PURPOSE: To analyze the recovery course of foveal microstructures in eyes with nonsurgical healing of full-thickness macular hole (FTMH). METHODS: By serial OCT scans, the temporal healing sequences were analyzed in ocular trauma, vitreomacular traction (VMT), cystoid macular edema (CME), and the remaining group. We evaluated correlations between the final best-corrected spectacle visual acuity and reconstruction time of external limiting membrane (ELM), and inner segment/outer segment (IS/OS). RESULTS: The healing (mean±standard deviation in months) most involved fusion at the level of the outer nuclear layer (ONL) (6.3±10.5) followed by restoration of ELM (9.1±13.8), and lastly, by IS/OS regeneration (13.1±19.5). In severe blunt ocular trauma, healing was fast and involved subretinal zipper glue-like reapposition with resulting outer retinal atrophy. Best spectacle-corrected visual acuity correlated with normalization of the clivus (p=0.012), faster ELM (p=0.006), and IS/OS reconstitution (p=0.024). Recurrence of FTMH occurred when the healing was halted (3 eyes) or was aberrant by lamellar hole epiretinal proliferation (LHEP) (3 eyes) or by the persistence of VMT (1 eye). CONCLUSION: Recovery sequences proceeded from the ONL to the deeper layers with BCVA correlating absolutely and temporally with the restoration of outer retinal layer integrity.

Clinical characteristics of full thickness macular holes that closed without surgery.

PURPOSE: To ascertain the anatomic factors that help achieve non-surgical sealing in full thickness macular hole (FTMH). METHODS: Retrospective collaborative study of FTMH that closed without surgical intervention. RESULTS: A total of 78 patients (mean age 57.9 years) included 18 patients with blunt ocular trauma, 18 patients that received topical or intravitreal therapies and 42 patients with idiopathic FTMH. Mean±SD of the initial corrected visual acuity (VA) in logMAR improved from 0.65±0.54 to 0.34±0.45 (p<0.001) at a mean follow-up of 33.8±37.1 months. FTMH reopened in seven eyes (9.0%) after a mean of 8.6 months. Vitreomacular traction was noted in 12 eyes (15.8%), perifoveal posterior vitreous detachment in 42 (53.8%), foveal epiretinal membrane in 10 (12.8%), cystoid macular oedema (CME) in 49 (62.8%) and subretinal fluid (SRF) in 20 (25.6%). By multivariate analysis, initial VA correlated to the height (p<0.001) and narrowest diameter of the hole (p<0.001) while final VA correlated to the basal diameter (p<0.001). Time for closure of FTMH (median 2.8 months) correlated to the narrowest diameter (p<0.001) and the presence of SRF (p=0.001). Mean time for closure (in months) was 1.6 for eyes with trauma, 4.3 for eyes without trauma but with therapy for CME, 4.4 for eyes without trauma and without therapy in less than 200 µm in size and 24.7 for more than 200 µm. CONCLUSION: Our data suggest an observation period in new onset FTMH for non-surgical closure, in the setting of trauma, treatment of CME and size <200 µm.

High Myopia and the Complement System: Factor H in Myopic Maculopathy.

High myopia (HM) is both a medical problem and refractive error of the eye owing to excessive eyeball length, which progressively makes eye tissue atrophic, and is one of the main causes for diminishing visual acuity in developed countries. Despite its high prevalence and many genetic and proteomic studies, no molecular pattern exists that explain the degenerative process underlying HM, which predisposes patients to other diseases like glaucoma, cataracts, retinal detachment and chorioretinal atrophy that affect the macular area. To determine the relation between complement Factors H (CFH) and D (CFD) and the maculopathy of patients with degenerative myopia, we studied aqueous humor samples that were collected by aspiration from 122 patients during cataract surgery. Eyes were classified according to eyeball axial length as high myopia (axial length > 26 mm), low myopia (axial length 23.5-25.9 mm) and control (axial length ˂ 23.4 mm). The degree of maculopathy was classified according to fundus oculi findings following IMI's classification. Subfoveal choroid thickness was measured by optical coherence tomography. CFH and CFD measurements were taken by ELISA. CFH levels were significantly high in the high myopia group vs. the low myopia and control groups (p ˂ 0.05). Significantly high CFH values were found in those eyes with choroid atrophy and neovascularization (p ˂ 0.05). In parallel, the CFH concentration correlated inversely with choroid thickness (R = -0.624). CFD levels did not correlate with maculopathy. All the obtained data seem to suggest that CFH plays a key role in myopic pathology.

Lipid Peroxidation in Subretinal Fluid: Some Light on the Prognosis Factors.

The aim of this study was to identify a relation between the clinical characteristics and differences in lipid peroxidation in the subretinal fluid (SRF) of rhegmatogenous retinal detached patients by malondialdehyde (MDA) quantification. We collected 65 SRF samples from consecutive patients during scleral buckling surgery in rhegmatogenous retinal detachment (RRD) eyes. In addition to a complete ophthalmic evaluation, we studied the refractive status, evolution time, and the number of detached retinal quadrants to establish the extension of RRD. We studied the clinical aspects and oxidative stress and compared the characteristics among groups. We found that neither the evolution time of RRD nor the patients' age correlated with the MDA concentration in the SRF. The MDA and the protein content of the SRF increased in the patients with high myopia and with more extended RRD. Our results suggest that oxidative imbalance was important in more extended retinal detachment (RD) and in myopic eyes and should be taken into account in the managing of these cases.

Validation of Automated Screening for Referable Diabetic Retinopathy With an Autonomous Diagnostic Artificial Intelligence System in a Spanish Population.

PURPOSE: The purpose of this study is to compare the diagnostic performance of an autonomous artificial intelligence (AI) system for the diagnosis of referable diabetic retinopathy (RDR) to manual grading by Spanish ophthalmologists. METHODS: Subjects with type 1 and 2 diabetes participated in a diabetic retinopathy (DR) screening program in 2011 to 2012 in Valencia (Spain), and two images per eye were collected according to their standard protocol. Mydriatic drops were used in all patients. Retinal images-one disc and one fovea centered-were obtained under the Medical Research Ethics Committee approval and de-identified. Exams were graded by the autonomous AI system (IDx-DR, Coralville, Iowa, United States), and manually by masked ophthalmologists using adjudication. The outputs of the AI system and manual adjudicated grading were compared using sensitivity and specificity for diagnosis of both RDR and vision-threatening diabetic retinopathy (VTDR). RESULTS: A total of 2680 subjects were included in the study. According to manual grading, prevalence of RDR was 111/2680 (4.14%) and of VTDR was 69/2680 (2.57%). Against manual grading, the AI system had a 100% (95% confidence interval [CI]: 97%-100%) sensitivity and 81.82% (95% CI: 80%-83%) specificity for RDR, and a 100% (95% CI: 95%-100%) sensitivity and 94.64% (95% CI: 94%-95%) specificity for VTDR. CONCLUSION: Compared to manual grading by ophthalmologists, the autonomous diagnostic AI system had high sensitivity (100%) and specificity (82%) for diagnosing RDR and macular edema in people with diabetes in a screening program. Because of its immediate, point of care diagnosis, autonomous diagnostic AI has the potential to increase the accessibility of RDR screening in primary care settings.

Use in clinical practice of an automated screening method of diabetic retinopathy that can be derived using a diagnostic artificial intelligence system. / Uso en la práctica clínica, de un método de cribado automatizado de retinopatía diabética derivable mediante un sistema de inteligencia artificial de diagnóstico.

BACKGROUND AND OBJECTIVE: To compare the diagnostic performance of an autonomous diagnostic artificial intelligence (AI) system for the diagnosis of derivable diabetic retinopathy (RDR) with manual classification. MATERIALS AND METHODS: Patients with type 1 and type 2 diabetes participated in a diabetic retinopathy (DR) screening program between 2011-2012. 2 images of each eye were collected. Unidentifiable retinal images were obtained, one centered on the disc and one on the fovea. The exams were classified with the autonomous AI system and manually by anonymous ophthalmologists. The results of the AI system and manual classification were compared in terms of sensitivity and specificity for the diagnosis of both (RDR) and diabetic retinopathy with decreased vision (VTDR). RESULTS: 10,257 retinal inages of 5,630 eyes of 2,680 subjects were included. According to the manual classification, the prevalence of RDR was 4.14% and that of VTDR 2.57%. The AI system recorded 100% (95% CI: 97-100%) sensitivity and 81.82% (95% CI: 80 -83%) specificity for RDR, and 100% (95% CI: 95-100%) of sensitivity and 94.64% (95% CI: 94-95%) of specificity for VTDR. CONCLUSIONS: Compared to the manual classification, the autonomous diagnostic AI system registered a high sensitivity (100%) and specificity (82%) in the diagnosis of RDR and macular edema in people with diabetes. Due to its immediate diagnosis, the autonomous diagnostic AI system can increase the accessibility of RDR screening in primary care settings.

Non-Mydriatic Ultra-Wide Field Imaging Versus Dilated Fundus Exam and Intraoperative Findings for Assessment of Rhegmatogenous Retinal Detachment.

BACKGROUND: to compare the extent of the detached retina and retinal tears location in rhegmatogenous retinal detachment (RRD) among non-mydriatic ultra-wide field (UWF) imaging, dilated fundus exam (DFE), and intraoperative evaluation. METHODS: this retrospective chart review comprised 123 patients undergoing surgery for RRD. A masked retina specialist analyzed the UWF fundus images for RRD area, status of the macula, and presence and location of retinal breaks. The same variables were collected from a database including DFE and intraoperative recordings. Evaluation methods were compared. RESULTS: mean age was 59.8 ± 14.9 years. Best-corrected visual acuity improved from 0.25 ± 0.3 (Snellen) to 0.67 ± 0.3 at 12 months (p = 0.009). The RRD description and assessment of macula status (34.5% macula-on) did not differ between UWF, DFE, and intraoperative examination. The inferior quadrant was involved most frequently (41.5%), followed by the superior (38.9%), temporal (27.8%) and nasal quadrant (14.8%). Intraoperative exam detected 96.7% of retinal tears compared with DFE (73.2%, p = 0.008) and UWF imaging (65%, p=0.003). UWF imaging and DFE did not differ significantly. CONCLUSION: RRD extent on DFE and UWF images was consistent with intraoperative findings. UWF and DFE detection of peripheral retinal tears was similar, but 25% of retinal breaks were missed until intraoperative evaluation.

Imbalance Between Oxidative Stress and Growth Factors in Human High Myopia.

Myopia is one of the commonest eye pathologies that could affect 2.56 billion people by 2020. Today high myopia is a leading cause of blindness worldwide due to associated ocular illness. Nevertheless, the cellular bases for these diseases to develop are unclear in many areas. We conducted a prospective study of oxidative stress and growth factors in human myopic and non myopic eyes in an attempt to increase our understanding of the underlying physiopathological conditions to adequately early diagnose, prevent and treat the retina problem that derives from myopia. Aqueous humor samples were obtained from 41 patients being operated for cataracts in our hospital. Axial length, refractive status and complete ophthalmologic examination were recorded. The VEGF and HGF levels were determined by an ELISA kit. Total antioxidant capacity and total nitrites/nitrate levels were established with a lab kit. We show for the first time an increase in the total nitrite levels in high myopia. We also propose for the first time the concurrence of three factors: myopia, oxidative stress, and oxidative stress together with growth factors in the same group of patients. In this way, it would not be accurate to envision high myopia as a type of normal myopia, but one with more diopters or longer axial length.

CNNs for automatic glaucoma assessment using fundus images: an extensive validation.

BACKGROUND: Most current algorithms for automatic glaucoma assessment using fundus images rely on handcrafted features based on segmentation, which are affected by the performance of the chosen segmentation method and the extracted features. Among other characteristics, convolutional neural networks (CNNs) are known because of their ability to learn highly discriminative features from raw pixel intensities. METHODS: In this paper, we employed five different ImageNet-trained models (VGG16, VGG19, InceptionV3, ResNet50 and Xception) for automatic glaucoma assessment using fundus images. Results from an extensive validation using cross-validation and cross-testing strategies were compared with previous works in the literature. RESULTS: Using five public databases (1707 images), an average AUC of 0.9605 with a 95% confidence interval of 95.92-97.07%, an average specificity of 0.8580 and an average sensitivity of 0.9346 were obtained after using the Xception architecture, significantly improving the performance of other state-of-the-art works. Moreover, a new clinical database, ACRIMA, has been made publicly available, containing 705 labelled images. It is composed of 396 glaucomatous images and 309 normal images, which means, the largest public database for glaucoma diagnosis. The high specificity and sensitivity obtained from the proposed approach are supported by an extensive validation using not only the cross-validation strategy but also the cross-testing validation on, to the best of the authors' knowledge, all publicly available glaucoma-labelled databases. CONCLUSIONS: These results suggest that using ImageNet-trained models is a robust alternative for automatic glaucoma screening system. All images, CNN weights and software used to fine-tune and test the five CNNs are publicly available, which could be used as a testbed for further comparisons.

The influence of storage method on the transparency of pig crystalline lens / A influência do método de armazenamento na transparência do cristalino de porco

ABSTRACT Purpose: The porcine eye is frequently used as a research model. This paper analyzes the effect of different storage methods on the transparency of pig crystalline lens. Methods: A spectral transmission curve (from 220 to 780 nm) for the crystalline lens was determined experimentally after storage in different conditions: saline solution, formalin, castor oil, and freezing at -80°C. The total transmission in the visible spectrum, which was used as an index of transparency, was calculated from these curves. For comparative purposes, fresh lenses were evaluated and used as controls. Results: Storing the porcine crystalline lens in saline solution or castor oil resulted in a transparency loss of approximately 10% after 24 h and storage in formalin resulted in a loss of nearly 30%. Storage by freezing at -80°C for 4 weeks maintained the transparency of the crystalline lens; the spectral transmission measured immediately after defrosting at room temperature coincided exactly with that of the freshly extracted lens. Conclusions: The transparency of porcine crystalline lens is affected by the storage method. The visible spectrum is the most affected, evidenced by the effect on the transparency and consequently the amount of light transmitted. The results show that freezing at -80°C maintains the transpa rency of the crystalline lens for at least 4 weeks.

RESUMO Objetivos: Olho de porco é frequentemente usa do como modelos de pesquisa. Este estudo analisa o efeito de di ferentes métodos de armazenamento na preservação da transparência do cristalino de porco. Métodos: Uma curva de transmissão espectral (de 220 até 780 nm) para o cristalino foi experimentalmente determinada após armazenamento em diferentes condições: solução salina, formol, óleo de mamona e congelamento a -80°C. Transmissão total do espectro visível, que foi usada como um índice de transparência foi calculada a partir dessas curvas. Para fins comparativos, lentes frescas foram avaliadas e usadas como controles. Resultados: O armazenamento do cristalino suíno em solução salina ou óleo de mamona resultou uma perda de transparência de aproximadamente 10% após 24 h e o armazenamento em formol resultou uma perda de quase 30%. O armazenamento por congelamento a -80°C durante 4 semanas manteve a transparência do cristalino; a transmissão espectral medida imediatamente após o descongelamen to à temperatura ambiente coincidiu exatamente com a da lente extraída recentemente. Conclusão: A transparência do cristalino suíno é afetada pelo método de armazenamento. O espectro visível é o mais afetado, evidenciado pelo efeito sobre a transparência e consequentemente a quantidade de luz transmitida. Os resultados mostram que o congelamento a -80°C mantém a transparência do cristalino suíno por pelo menos 4 semanas.

The influence of storage method on the transparency of pig crystalline lens.

PURPOSE: The porcine eye is frequently used as a research model. This paper analyzes the effect of different storage methods on the transparency of pig crystalline lens. METHODS: A spectral transmission curve (from 220 to 780 nm) for the crystalline lens was determined experimentally after storage in different conditions: saline solution, formalin, castor oil, and freezing at -80°C. The total transmission in the visible spectrum, which was used as an index of transparency, was calculated from these curves. For comparative purposes, fresh lenses were evaluated and used as controls. RESULTS: Storing the porcine crystalline lens in saline solution or castor oil resulted in a transparency loss of approximately 10% after 24 h and storage in formalin resulted in a loss of nearly 30%. Storage by freezing at -80°C for 4 weeks maintained the transparency of the crystalline lens; the spectral transmission measured immediately after defrosting at room temperature coincided exactly with that of the freshly extracted lens. CONCLUSIONS: The transparency of porcine crystalline lens is affected by the storage method. The visible spectrum is the most affected, evidenced by the effect on the transparency and consequently the amount of light transmitted. The results show that freezing at -80°C maintains the transpa rency of the crystalline lens for at least 4 weeks.

Bevacizumab Diminishes Inflammation in an Acute Endotoxin-Induced Uveitis Model.

Introduction: Uveitis is an eye disease characterized by inflammation of the uvea and an early and exhaustive diagnosis is essential for its treatment. The aim of our study is to assess the potential toxicity and anti-inflammatory efficacy of Bevacizumab in an experimental uveitis model by subcutaneously injecting lipopolysaccharide into Lewis rats and to clarify its mechanism. Material and Methods: Blood-aqueous barrier integrity was assessed 24 h after endotoxin-induced uveitis (EIU) by analyzing two parameters: cell count and protein concentration in aqueous humors. Histopathology of all eye structures was also studied. Enzyme-linked immunosorbent analyses of the aqueous humor samples were performed in order to calculate the diverse chemokine and cytokine protein levels and oxidative stress-related markers were also evaluated. Results: The aqueous humor's cellular content significantly increased in the group treated with only Bevacizumab, but it had no effect on retina histopathological grading. Nevertheless, the inflammation noted in ocular structures when administering Bevacizumab with endotoxin was mostly prevented since aqueous humor cell content considerably lowered, and concomitantly with a sharp drop in uveal, vitreous, and retina histopathological grading. The values of the multi-faceted cytokine IL-2 also significantly decreased (p < 0.05 vs. endotoxin group), and the protective IL-6 and IL-10 cytokines values rose with related anti-oxidant system recovery (p < 0.05 vs. endotoxin group). Concurrently, some related M1 macrophage chemokines substantially increased, e.g., GRO/KC, a chemokine that also displays any kind of protective role. Conclusion: All these results revealed that 24 h after being administered, Bevacizumab treatment in EIU significantly prevented inflammation in various eye structures and correct results in efficacy vs. toxicity balance were obtained.

Intra-ocular lens optical changes resulting from the loading of dexamethasone.

To study the optical changes on hydrogel-silicone intraocular lenses (IOLs) resulting from loading them with dexamethasone. We used prototype hydrogel(pHEMA)-silicone IOLs and loaded the matrices with an anti-inflammatory drug (dexamethasone). The optical properties we analyzed experimentally were a) modulation transfer function (MTF); b) spectral transmission; c) diopter power. These determinations were performed on drug-loaded IOLs, IOLs that had released the drug, and IOLs that had not been drug-loaded. Loading a hydrogel-silicone IOL with dexamethasone results in impairment of its optical qualities, in particular its MTF and spectral transmission, but not dioptric power. However, once the drug has been released, it almost recovers its initial optical properties.

Electrophysiological and clinical tests in dry age-related macular degeneration follow-up: differences between mfERG and OCT.

BACKGROUND: Age-related macular degeneration (AMD) is one of the major causes of progressive and debilitating visual impairment in developed countries and has become a growing health and social issue that needs to be addressed. Imaging techniques and functional tests are useful to assess the degree of macular dysfunction and AMD progression. However, given the slow progression of the disease, it is necessary to identify which techniques are more sensitive for the diagnosis and monitoring of patients with AMD. PURPOSE: To study changes observed with both imaging techniques and electrophysiological tests in dry AMD-diagnosed patients during 2 years in order to identify the most sensitive technique. METHODS: Fundus photography, OCT (macular thickness and number of drusen), Pattern VEP (P100 wave), Pattern ERG (P50 wave) and multifocal ERG (central rings) were carried out in 30 patients that were diagnosed with dry AMD in both eyes. The tests were repeated 1 and 2 years later. RESULTS: No statistically significant changes were observed in visual acuity or in the severity of the disease throughout the study. OCT showed an increase in the number of drusen, as well as in macular thickness. As for the electrophysiological techniques, no significant changes were observed throughout the study in Pattern VEP or Pattern ERG. mfERG showed significant alterations. Statistical analysis showed that mfERG is more efficient in detecting changes throughout the experimental period. CONCLUSIONS: OCT and mfERG are useful in the diagnosis and monitoring of dry AMD patients, whilst mfERG is the most sensitive technique to study the progression of this disease in short periods of time.

Looking into aqueous humor through metabolomics spectacles - exploring its metabolic characteristics in relation to myopia.

Aqueous humor is the transparent fluid found in the anterior chamber of the eye that provides the metabolic requirements to the avascular tissues surrounding it. Despite the fact that metabolomics could be a powerful tool in the characterization of this biofluid and in revealing metabolic signatures of common ocular diseases such as myopia, it has never to our knowledge previously been applied in humans. In this research a novel method for the analysis of aqueous humor is presented to show its application in the characterization of this biofluid using CE-MS. The method was extended to a dual platform method (CE-MS and LC-MS) in order to compare samples from patients with different severities of myopia in order to explore the disease from the metabolic phenotype point of view. With this method, a profound knowledge of the metabolites present in human aqueous humor has been obtained: over 40 metabolites were reproducibly and simultaneously identified from a low volume of sample by CE-MS, including among others, a vast number of amino acids and derivatives. When this method was extended to study groups of patients with high or low myopia in both CE-MS and LC-MS, it has been possible to identify over 20 significantly different metabolite and lipid signatures that distinguish patients based on the severity of myopia. Among these, the most notable higher abundant metabolites in high myopia were aminooctanoic acid, arginine, citrulline and sphinganine while features of low myopia were aminoundecanoic acid, dihydro-retinoic acid and cysteinylglycine disulfide. This dual platform approach offered complementarity such that different metabolites were detected in each technique. Together the experiments presented provide a whelm of valuable information about human aqueous humor and myopia, proving the utility of non-targeted metabolomics for the first time in analyzing this type of sample and the metabolic phenotype of this disease.

Light transmission and ultraviolet protection of contact lenses under artificial illumination.

PURPOSE: To determine the spectral transmission of contact lenses (CLs), with and without an ultraviolet (UV) filter to evaluate their capacity for protection under UV radiation from artificial illumination (incandescent, fluorescent, xenon (Xe) lamps, or white LEDs (light-emitting diode)). METHODS: The transmission curves of nine soft CLs were obtained by using a PerkinElmer Lambda 35 UV-vis spectrophotometer. A CIE standard was used for the emission spectra of incandescent and fluorescent lamps, and Xe lamps and white LEDs were measured by using an International Light Technologies ILT-950 spectroradiometer. RESULTS: Five of the nine soft CLs analysed state that they incorporate UV filters, but the other four do not specify anything in this regard. The spectral transmission of all the CLs studied is excellent in the visible region. The CLs with UV filters filter out this radiation more or less effectively. Xe lamps emit a part in the UV region. Incandescent, fluorescent and white LEDs do not emit at all in the UV. CONCLUSIONS: Incorporating UV filters is important when the illumination is from a Xe lamp since this light source emits in the UV region. This, however, does not occur with incandescent and fluorescent lamps or white LEDs. The CLs that do incorporate UV filters meet all the standard requirements that the U.S. FDA (Food and Drug Administration) has for UV-blocking CLs Class II (OcularScience, CooperVision and Neolens), and AcuvueMoist and HydronActifresh400 even comply with the stricter Class I. The CLs without UV filters let UVA, UVB and even some UVC through.

A rapid method for measuring intraocular lens power in vitro with a focimeter.

In this paper we describe a new method for measuring the intraocular lens (IOL) power using a focimeter, a negative ophthalmic lens and a saline solution (0.9% NaCl). To test this we measured the power of 58 different IOLs and we compared them with the power stated by the manufacturer. Despite the limitations, the results show a good correlation.