Simultaneous Comparison of Aqueous Humor and Serum Metabolic Profiles of Diabetic and Nondiabetic Patients Undergoing Cataract Surgery-A Targeted and Quantitative Metabolomics Study.

The aim of this study was to compare the aqueous humor (AH) and serum concentrations of metabolites in diabetic (n = 36) and nondiabetic (n = 36) senior adults undergoing cataract surgery. Blood samples were collected before surgery and AH during surgery. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS)-based targeted metabolomic and lipidomic analyses of samples were performed using the AbsoluteIDQ® p180 kit. Out of 188 metabolites targeted by the kit, 41 and 133 were detected in >80% of AH and serum samples, respectively. Statistical analysis performed to indicate metabolites differentiating diabetic and nondiabetic patients showed 8 and 20 significant metabolites in AH and serum, respectively. Pathway analysis performed for significant metabolites revealed that galactose metabolism is mostly affected in the AH, while arginine biosynthesis is mostly affected in the serum. Among metabolites that differentiate diabetic and nondiabetic patients, arginine was the only metabolite common to both serum and AH samples, as well as the only one with a decreased concentration in both body fluids of diabetic patients. Concentrations of the rest were elevated in AH and lowered in serum. This may suggest different mechanisms of diabetes-related dysregulation of the local metabolism in the eye in comparison to systemic changes observed in the blood.

Long-term outcomes of the intravitreal injection of ranibizumab for the treatment of choroidal neovascularization secondary to pathologic myopia.

PURPOSE: To analyze the long-term outcomes and safety of intravitreal ranibizumab injections in myopic choroidal neovascularization (CNV). METHODS: A retrospective non-randomized analysis of consecutive cases included 17 eyes from 17 patients with subfoveal myopic CNV, treated with intravitreal ranibizumab with at least 30-month follow-up. The patients received three injections monthly, followed by pro re nata regimen. Best-corrected visual acuity (BCVA) measurement, optical coherence tomography and fluorescein angiography were carried out at the baseline and at monthly intervals thereafter. RESULTS: Mean follow-up period was 51 months (range 30-98 months). In 12 patients (70.6%), BCVA improved by at least 1 Snellen line, with at least 3-line improvement observed in the case of 8 eyes (47%). Mean central foveal thickness (CFT) decreased from 384.65 ± 103.3 µm at the baseline to 264 ± 86.2 µm at the last follow-up examination (p < 0.001). The final OCT examination revealed 59% (10/17) eyes with CNV-related macular atrophy. Mean number of injections over the follow-up period was 4.82 ± 2.04 per person. Nine patients (53%) required re-injection of the anti-VEGF agent; the mean number of re-injections in this group was 3.44 ± 1.34 per person (range 2-6). No significant adverse events were recorded during the study period. CONCLUSIONS: Intravitreal ranibizumab is an effective and safe treatment for CNV secondary to pathologic myopia, contributing to long-term vision improvement and CFT reduction.

An exploratory LC-MS-based metabolomics study reveals differences in aqueous humor composition between diabetic and non-diabetic patients with cataract.

Cataract is the leading cause of blindness worldwide. Epidemiological studies revealed up to a fivefold increased prevalence of cataracts in diabetic subjects. Metabolomics is nowadays frequently implemented to understand pathophysiological processes responsible for disease occurrence and progression. It has also been used recently to study the metabolic composition of aqueous humor (AH). AH is a transparent fluid which fills the anterior and posterior chambers of the eye. It supplies nutrients and removes metabolic waste from avascular tissues in the eye. The aim of this study was to use metabolomics to compare the AH of diabetic and non-diabetic patients undergoing cataract surgery. Several antioxidants (methyltetrahydrofolic acid, taurine, niacinamide, xanthine, and uric acid) were found decreased (-22 to -61%, p-value 0.05-0.003) in AH of diabetics. Also amino acids (AA) and derivatives were found decreased (-21 to -36%, p-value 0.05-0.01) while glycosylated AA increased (+75-98%, p-value 0.03-0.009) in this group of patients. Metformin was detected in AH of people taking this drug. To our knowledge, this is the first metabolomics study aiming to assess differences in AH composition between diabetic and non-diabetic patients with cataract. An increased oxidative stress and perturbations in amino acid metabolism in AH may be responsible for earlier cataract onset in diabetic patients.

Extent of interocular (a)symmetry based on the metabolomic profile of human aqueous humor.

Aims: Interocular comparison of the metabolomic signature of aqueous humor (AH) was performed. The aim of the study was to quantitatively evaluate the symmetry in concentrations of various metabolites belonging to different categories. Methods: The study included AH samples from 23 patients, 74.17 ± 11.52 years old, undergoing simultaneous bilateral cataract surgery at the Ophthalmology Department of the Medical University of Bialystok, Poland. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS)-based targeted metabolomics and lipidomics analyses of AH samples were performed using the AbsoluteIDQ® p180 kit. Out of 188 metabolites available in the kit, 67 were measured in the majority (>70%) of the samples: 21/21 amino acids, 10/22 biogenic amines, 9/40 acylcarnitines, 0/14 lysophosphatidylcholines, 21/76 phosphatidylcholines, 5/15 sphingolipids, and 1/1sum of hexoses. Results: The comparison of both eyes revealed that the concentrations of metabolites did not differ significantly (p < 0.05) except for taurine (p = 0.037). There was moderate-to-strong positive interocular correlation (r > 0.5) between most metabolites regarding concentration. This was confirmed by the high intraclass correlation coefficient (ICC) values of different levels, which varied for the different metabolites. However, there were exceptions. Correlations were not significant for 2 acylcarnitines (tiglylcarnitine and decadienylcarnitine) and 3 glycerophospholipids (PC aa C32:3, PC aa C40:2, and PC aa C40:5). Conclusion: With a few exceptions, a single eye was found to be representative of the fellow eye in terms of the concentration of most of the analyzed metabolites. The degree of intraindividual variability in the AH of fellow eyes differs for particular metabolites/metabolite categories.

A prospective, randomised study of the effect of fixation sutures during phacotrabeculectomy on intraocular pressure and incidence of ptosis.

We investigated the effects of different intraoperative eyeball fixation techniques (superior rectus muscle suture [MS] and traction suture at the corneal limbus [CS]), on intraocular pressure (IOP) and the incidence of ptosis after phacotrabeculectomy. Forty-one eyes with different glaucoma types which qualified for phacotrabeculectomy were included. Twenty-three and eighteen patients were included in the CS and MS groups, respectively. The IOP, best-corrected visual acuity (BCVA), and margin reflex distance were assessed preoperatively and 3, 6, and 12 months post-operatively. Preoperatively, the mean IOPs (± standard deviation) in the CS and MS groups were 23.6 ± 7.3 mmHg and 24.3 ± 6.6 mmHg (p > 0.05), respectively. At 3 and 6 months post-surgery, the mean IOPs were significantly lower in the CS group than in the MS group: 13.9 ± 3.0 mmHg vs. 17.7 ± 3.5 mmHg (p = 0.001), and 13.9 ± 4.9 mmHg vs. 17.2 ± 3.5 mmHg (p = 0.005), respectively (mean difference: 3.9, 95% confidence interval 1.7-6.1). At 12 months, the mean postoperative IOPs were 15.2 ± 3.5 mmHg and 14.9 ± 3.6 mmHg in the CS and MS groups, respectively (p > 0.05). At 6 months, the BCVAs were 0.91 ± 0.15 and 0.71 ± 0.3 (p = 0.029) in the CS and MS groups, respectively; BCVAs were 0.91 ± 0.15 and 0.71 ± 0.3 (p = 0.029) in the CS and MS groups, respectively; the difference was non-significant 12 months post-surgery (0.78 ± 0.32 vs. 0.74 ± 0.30, p = 0.553). Postoperative ptosis was observed in 4 (17%) and zero patients in the CS and MS groups, respectively, but the difference was not statistically significant (p = 0.118). The study was not powered sufficiently to detect statistically significant changes in exploratory endpoints. The study was not powered sufficiently to detect statistically significant differences between groups in exploratory endpoints.

LC-MS-Based Metabolic Fingerprinting of Aqueous Humor.

Aqueous humor (AH) is a transparent fluid which fills the anterior and posterior chambers of the eye. It supplies nutrients and removes metabolic waste from avascular tissues in the eye. Proper homeostasis of AH is required to maintain adequate intraocular pressure as well as optical and refractive properties of the eye. Application of metabolomics to study human AH may improve knowledge about the molecular mechanisms of eye diseases. Until now, global analysis of metabolites in AH has been mainly performed using NMR. Among the analytical platforms used in metabolomics, LC-MS allows for the highest metabolome coverage. The aim of this study was to develop a method for extraction and analysis of AH metabolites by LC-QTOF-MS. Different protocols for AH preparation were tested. The best results were obtained when one volume of AH was mixed with one volume of methanol : ethanol (1 : 1). In the final method, 2 µL of extracted sample was analyzed by LC-QTOF-MS. The method allowed for reproducible measurement of over 1000 metabolic features. Almost 250 metabolites were identified in AH and assigned to 47 metabolic pathways. This method is suitable to study the potential role of amino acids, lipids, oxidative stress, or microbial metabolites in development of ocular diseases.

[Ocular findings in patients with Steinert myotonic dystrophy]. / Objawy okulistyczne u chorych z dystrofia miotoniczna Steinerta.

The authors present one of many myotonic dystrophies: Steinert myotonic dystrophy (Steinert disease), which is a disease occuring seldom, and causing a lot of problems during the diagnostic and treatment process. Genetic factors, results of the histopathology tests, main clinical symptoms, particularly ophtalmic manifestation are described in this article.

[Genetic abnormalities underlying formation of choroidal melanoma]. / Podloze genetyczne czerniaka zlosliwego blony naczyniowej oka.

Genetic mechanisms underlying formation of ocular and skin melanoma differ in many aspects, the former being still poorly understood. It has been suggested that choroidal melanoma can develop due to accumulation of genetic alterations in the DNA of normal melanocytes. Neoplastic transformation in the choroid can be triggered as a consequence of the following genetic alterations: --deletions and/or amplifications in the genetic material, usually in the chromosome 3, 6, 8, 9, 11, and 18; --point mutations, especially within some egzones, which leads to monosomia or loss of heterozygosity of the chromosome. As a consequence of the above alterations a number of false codons can appear resulting in formation of defective enzymatic proteins. Some of these proteins, like p16 and p14, normally play a role of suppressors of oncogenesis and defects in their structure may result in melanoma formation.

[Loss of heterozygosity at microsatellite marker localised near the metalloproteinase gene in patients with PEX syndrome]. / Utrata heterozygotycznosci w markerze mikrosatelitarnym zlokalizowanym w poblizu genu metaloproteinazy u chorych z zespolem pseudoeksfoliacji.

PURPOSE: The aim of the study was to evaluate the possible occurrence of loss of heterozygosity (LOH) at microsatellite marker localised near the area for metalloproteinase gene in the anterior capsule, lens nucleus, iris and trabeculum samples taken from patients with pseudoexfoliation syndrome (PEX). MATERIAL AND METHODS: In our study we examined 19 patients (12 women and 7 men) with PEX syndrome who underwent surgical treatment for glaucoma, cataract or both at the same time. The mean age was 75.5 +/- 4.7, range 64-86. Specimens of the iris, anterior capsule, trabeculum and lens nucleus were taken to evaluate the possible occurrence of LOH at microsatellite marker D7S820 with fluorescent multiplex PCR method. RESULTS: LOH was displayed in 44% specimens of anterior capsule, 33% of iris specimen. In lens nucleus and trabeculum specimen LOH did not occur. CONCLUSIONS: The high frequency of LOH in PEX patients at locus D7S820 suggests that genetic factors may be involved in the etiology and pathogenesis of PEX.