Successive Acanthamoeba Corneal Isolates Identified in Poland Monitored in Terms of In Vitro Dynamics.

BACKGROUND: Amoebae of the genus Acanthamoeba cause a sight-threatening infection called Acanthamoeba keratitis. It is considered a rare disease in humans but poses an increasing threat to public health worldwide, including in Poland. We present successive isolates from serious keratitis preliminary examined in terms of the identification and monitoring of, among others, the in vitro dynamics of the detected strains. METHODS: Clinical and combined laboratory methods were applied; causative agents of the keratitis were identified at the cellular and molecular levels; isolates were cultivated in an axenic liquid medium and regularly monitored. RESULTS: In a phase-contrast microscope, Acanthamoeba sp. cysts and live trophozoites from corneal samples and in vitro cultures were assessed on the cellular level. Some isolates that were tested at the molecular level were found to correspond to A. mauritanensis, A. culbertsoni, A. castellanii, genotype T4. There was variability in the amoebic strain dynamics; high viability was expressed as trofozoites' long duration ability to intense multiply. CONCLUSIONS: Some strains from keratitis under diagnosis verification and dynamics assessment showed enough adaptive capability to grow in an axenic medium, allowing them to exhibit significant thermal tolerance. In vitro monitoring that was suitable for verifying in vivo examinations, in particular, was useful to detect the strong viability and pathogenic potential of successive Acanthamoeba strains with a long duration of high dynamics.

Pupil diameter during cataract surgery after intracameral injection of the first ready-to-use combination of mydriatics and anaesthetic at the beginning of surgery in patients with a preoperative pupil diameter <6 mm.

PURPOSE: We evaluated, in a real-life setting, the effect of Mydrane® (ready-to-use combination of tropicamide, phenylephrine hydrochloride and lidocaine, injected into the anterior chamber at the beginning of cataract surgery to induce mydriasis and intraocular anaesthesia) on the pupil diameter during cataract surgery in patients with a preoperative pupil diameter <6 mm after the use of topical mydriatics. METHODS: We collected and analysed the data of 59 consecutive patients whose pupils dilated to a diameter <6 mm after the administration of mydriatic eye drops during the preoperative visit and who received Mydrane® during cataract surgery. RESULTS: In the group of 59 patients with a preoperative pupil diameter <6 mm after topical mydriatics, cataract surgery was performed in 36 patients (61.0%) using only Mydrane® to obtain mydriasis, with no additional drug or medical device. The mean pupil diameters in this group (36 of 59) during the preoperative assessment after topical mydriatics and just before capsulorhexis when Mydrane® was injected during surgery were 5.1 ± 0.74 and 6.15 ± 1.14 mm. Additional drugs were used in 23 patients (39%). In this group, the mean pupil diameters after topical mydriatics and just before capsulorhexis using Mydrane® were 4.58 ± 1.06 and 5.6 ± 1.26 mm, respectively. CONCLUSION: In a real-life setting, the mean pupil diameter achieved during cataract surgery after the intracameral injection of Mydrane® in patients with a preoperative pupil diameter <6 mm was over 1 mm larger than the mean pupil diameter after topical mydriatics, despite the trauma caused by the operation.

Canaloplasty - Efficacy and Safety in an 18-Month Follow Up Period, and Analysis of Outcomes in Primary Open Angle Glaucoma Pigmentary Glaucoma and Pseudoexfoliative Glaucoma.

PURPOSE: Open-angle glaucoma (OAG), accounting for 90% of all glaucoma cases, is a progressive optic nerve neuropathy. It may lead to irreversible loss of visual field and complete blindness. When conservative treatment becomes insufficient to stop OAG progression, a surgical intervention is considered. Currently, canaloplasty procedure is being introduced instead of conventional trabeculectomy for invasive OAG treatment. The aim of the study is to asses safety and efficacy of canaloplasty. METHODS: This prospective study included 67 eyes that received 360° canaloplasty with placement of a tensioning suture. Primary OAG (n = 35), secondary OAG in pseudoexfoliative syndrome (n = 13), and pigmentary glaucoma (n = 19) patients were included. Control check-ups were conducted pre-operatively and in a 18-month follow-up time. Study endpoints involved reduction in IOP values and in the number of glaucoma medications after the intervention. RESULTS: The intervention led to a significant 38% reduction in IOP value from the preoperative baseline to 18 months after the intervention. The number of medications decreased significantly by 89%. At 18 months postoperative, 79% eyes did not require any glaucoma medications. The incidence of complications after canaloplasty was low, and none of the adverse effects were vision threatening. A surgically-induced astigmatism was the most frequent complication. Pigmentary glaucoma patients were the most beneficial subgroup, with 50% reduction in IOP, the highest success rate, and 98% reduction in the number of medications used. CONCLUSION: This study proved that canaloplasty is an efficient and safe procedure in OAG eyes.

Stable Mydriasis After Intracameral Injection of a Combination of Mydriatics and Anesthetic During Cataract Surgery: A Real-Life, Multicenter Study.

Purpose: To evaluate the effect of Mydrane (contains tropicamide, phenylephrine hydrochloride, and lidocaine hydrochloride) on time needed to induce mydriasis and mydriasis stability during cataract surgery. Methods: This was an observational, non-interventional, multicenter study of patients undergoing cataract surgery who received Mydrane for mydriasis and intraocular anesthesia. The study was conducted at seven ophthalmology departments at university hospitals in Poland. Patients admitted for cataract surgery within a 2-week period were asked to participate in the study. Patients whose pupils dilated to a diameter ≥6 mm after topical mydriatic administration during preoperative examinations were scheduled to receive Mydrane and included in the registry. No additional inclusion criteria were used. Patients' medical histories, examination results, and operative details were recorded. Pupil diameter was measured during surgery. Surgeons were asked to complete a Likert-based survey in parallel. Results: A total of 307 patients were enrolled. The mean pupil diameter was 7.0 ± 1.0 mm before capsulorhexis and 6.9 ± 1.2 mm before lens implementation. A pupil diameter ≥6 mm was achieved in 91.9% and 87.6% of patients before capsulorhexis and lens implantation, respectively. We asked 58 surgeons whether they agreed with the statement "Mydriasis was obtained in a short time after the administration of Mydrane"; the surgeons agreed with this statement after 92.2% (283/307) of surgeries. In addition, after 88.2% of surgeries, the surgeons agreed with the statement "Mydriasis was stable after the administration of Mydrane." Conclusions: Mydriasis was rapidly and stably obtained after Mydrane injection, as demonstrated by pupil diameter measurements during surgery and surgeons' feedback.

The Genetic and Endoplasmic Reticulum-Mediated Molecular Mechanisms of Primary Open-Angle Glaucoma.

Glaucoma is a heterogenous, chronic, progressive group of eye diseases, which results in irreversible loss of vision. There are several types of glaucoma, whereas the primary open-angle glaucoma (POAG) constitutes the most common type of glaucoma, accounting for three-quarters of all glaucoma cases. The pathological mechanisms leading to POAG pathogenesis are multifactorial and still poorly understood, but it is commonly known that significantly elevated intraocular pressure (IOP) plays a crucial role in POAG pathogenesis. Besides, genetic predisposition and aggregation of abrogated proteins within the endoplasmic reticulum (ER) lumen and subsequent activation of the protein kinase RNA-like endoplasmic reticulum kinase (PERK)-dependent unfolded protein response (UPR) signaling pathway may also constitute important factors for POAG pathogenesis at the molecular level. Glaucoma is commonly known as a 'silent thief of sight', as it remains asymptomatic until later stages, and thus its diagnosis is frequently delayed. Thereby, detailed knowledge about the glaucoma pathophysiology is necessary to develop both biochemical and genetic tests to improve its early diagnosis as well as develop a novel, ground-breaking treatment strategy, as currently used medical therapies against glaucoma are limited and may evoke numerous adverse side-effects in patients.

Retinal arterial remodeling in patients with pheochromocytoma or paraganglioma and its reversibility following surgical treatment.

OBJECTIVE: Structural abnormalities in resistance arteries are a hallmark of patients with hypertension. In hypertensive patients with pheochromocytoma or paraganglioma (PPGL), it is still a matter of debate whether structural vascular changes are because of elevated blood pressure (BP) or to toxic effects of elevated circulating catecholamines. Hence, the aim of our study was to assess whether catecholamine excess and/or elevated BP affect the structure of small retinal arteries in patients with catecholamine-producing tumors. METHODS: The study included 27 patients with PPGL and 27 hypertensive patients. All patients underwent biochemical tests for catecholamine excess, echocardiography and analyses of scanning-laser-Doppler-flowmetry (SLDF) both at baseline and 12 months following surgical resection of PPGL. RESULTS: Baseline retinal arterial diameter, arterial wall thickness and wall cross sectional area (WCSA) were higher in patients with PPGL as compared with subjects without PPGL (arterial diameter: 110 ±â€Š16.5 vs. 99.5 ±â€Š10.8 µm, wall thickness: 16.3 ±â€Š6.0 vs. 13.5 ±â€Š4.0 µm, WCSA: 4953.9 ±â€Š2472.8 vs. 3784.1 ±â€Š1446.3 µm, P < 0.05). Significant correlations were noted between wall thickness and WCSA and echocardiographic parameters assessing diastolic and systolic function of left ventricle. No correlations between retinal parameters, BP level and plasma concentrations of metanephrines were observed. In patients with PPGL, there were postoperative decreases in wall thickness (16.4 ±â€Š15.8 vs. 14.8 ±â€Š4.7 µm; P = 0.011) and WLR (0.42 ±â€Š0.13 vs. 0.37 ±â€Š0.10; P = 0.003) at 12 months after surgical removal of tumors. CONCLUSION: This is the first study to demonstrate that catecholamine excess is related to thickening of retinal arteries independent of BP and reversible after surgical cure. These data support a role of catecholamines in vascular remodeling in PPGL patients.

Prevalence of bacteria and fungi in samples of cornea preservation fluid.

INTRODUCTION: Recipients of corneal transplants are at risk of healthcare-associated infections, which, apart from other causes of surgical site infections, may also occur as a result of the transfer of infected corneal tissue. In this study we assessed the risk of bacterial and fungal infections based on the results of routine microbiological testing of cornea preservation fluid samples. MATERIAL AND METHODS: We examined a total of 725 samples of corneal preservation fluid, obtained during a period of 3 years (2011-2013). Corneal preservation fluid samples were cultured and identified in accordance with standard microbiological methods. RESULTS: The analysis comprised 725 samples of corneal preservation fluid, of which 32 (4.4%) samples tested positively in microbiological cultures. In total, 34 strains of bacteria and fungi were cultured. Gram-positive bacteria, Gram-negative bacteria and fungi comprised 85.3%, 8.8% and 5.9% of these strains, respectively. Analysis of the susceptibility of the cultured bacterial isolates to gentamicin was also performed, as this antibiotic is present in the composition of corneal preservation fluid. Among the cultured bacterial strains, 10 (33.3%) were resistant to gentamicin. None of the 32 patients who received a cornea stored in preservation fluid contaminated with bacteria and/or fungi demonstrated infectious complications in the surgical site within 1 year following cornea transplantation. CONCLUSIONS: We postulate that perioperative antibiotic prophylaxis in cornea transplant recipients is important in preventing bacterial infections derived from the donor cornea. We believe that the addition of an antifungal agent to commercially available cornea preservation fluids should also be considered.

The relationship between HDAC6, CXCR3, and SIRT1 genes expression levels with progression of primary open-angle glaucoma.

BACKGROUND: Primary open-angle glaucoma (POAG) belongs to neurodegenerative diseases. Its etiology is not fully understood. However, a lot of reports have indicated that many biochemical molecules are involved in the retinal ganglion cell damage. Therefore, the purpose of this study was to evaluate a relationship between HDAC6, CXCR3, and SIRT1 genes expression levels with the occurrence risk of POAG and its progression. MATERIALS AND METHODS: The study included 34 glaucoma patients and 32 subjects without glaucoma symptoms. RNA was isolated from peripheral blood lymphocytes. Level of mRNA expression was determined by real-time PCR method. RESULTS: Our results have shown significant association of the HDAC6 and SIRT1 expression levels with progression of POAG according to rim area (RA) value, p = 0.041; p = 0.012. Moreover, the analysis of the CXCR3 expression level showed a correlation with progression of POAG based on RA and cup disc ratio (c/d) value, p = 0.006 and p = 0.012, respectively. CONCLUSIONS: The expression level of HDAC6, CXCR3, and SIRT1 genes may be involved in the progression of POAG.

Analysis of the polymorphic variants of RAN and GEMIN3 genes and risk of Primary Open-Angle Glaucoma in the Polish population.

BACKGROUND: Glaucoma is considered as a neurodegenerative disorder in which the optic nerve damage leads to irreversible blindness. Many scientific findings indicate miRNA implication in the neurodegeneration process. In this study, we aimed to evaluate the polymorphic variants of miRNA processing genes, RAN (rs14035) and GEMIN3 (rs197388), and their association with a risk of primary open-angle glaucoma (POAG) in relation to selected clinical parameters. MATERIALS AND METHODS: The study included 246 POAG patients and 188 controls. The selected gene polymorphisms were analyzed by TaqMan SNP Genotyping Assay using DNA extracted from blood samples. RESULTS: The obtained results indicated that the AA genotype of rs197388 as well as the A allele in the same gene may be associated with an elevated risk of POAG development (P = 0.021, P = 0.017 respectively). The correlation between the data and clinical parameters has shown that the A allele of rs197388 in relation to retinal nerve fiber layer(RNFL) could be responsible for an increased risk of glaucoma occurrence (P = 0.028), while the AT genotype could be associated with a decreased risk of POAG according to the mean deviation parameter (P = 0.023). CONCLUSION: Our data has shown that GEMIN3 gene (rs197388) polymorphisms might be associated with a risk of POAG development in the Polish population. This is the first report evaluating the polymorphic variants of miRNA processing genes, RAN and GEMIN3, with a changed risk of glaucoma.

Retinal Photoreceptors and Microvascular Changes in Prediabetes Measured with Adaptive Optics (rtx1™): A Case-Control Study.

BACKGROUND: Patients with prediabetes are at risk for diabetes, cardiovascular events, and microvascular complications. The rtx1 (Imagine Eyes, France) permits early detection of changes in the retinal photoreceptors and vessels. OBJECTIVE: Cone parameters and retinal microvasculature were analyzed with the rtx1 in 12 prediabetic patients and 22 healthy subjects. The analysis was based on cone density (DM), interphotoreceptor distance (SM), cone packing regularity, and retinal vessel parameters: wall thickness, lumen diameter (LD), wall-to-lumen ratio (WLR), and cross-sectional area of the vascular wall. RESULTS: DM in the prediabetic group was not significantly lower than that in the control group (18,935 ± 1713 cells/mm2 and 19,900 ± 2375 cells/mm2, respectively; p = 0.0928). The LD and WLR means differed significantly between the prediabetic and the control groups (LD 94.3 ± 10.9 versus 101.2 ± 15, p = 0.022; WLR 0.29 ± 0.05 versus 0.22 ± 0.03, p < 0.05). A multivariate regression analysis showed that the WLR was significantly correlated with BMI and total cholesterol. CONCLUSIONS: Abnormalities found in rtx1 examinations indicated early signs of arteriolar dysfunction, prior to impaired glucose tolerance progressing to diabetes. The rtx1 retinal image analysis offers noninvasive measurement of early changes in the vasculature that routine clinical examination cannot detect.

Is atrial fibrillation a risk factor for normal-tension glaucoma?

Glaucoma (GL) and atrial fibrillation (AF) are diseases of significant social importance. Cardiovascular disorders such as systemic hypertension, hypotension, increased blood viscosity, vasospasm, and diabetes are potential risk factors of GL, especially when intraocular pressure is not elevated. Only a few studies have reported a possible connection between cardiac arrhythmias and GL. The purpose of this study was to evaluate the risk of GL in patients with AF.A total of 117 patients were included in the study, 79 with AF (AF group) and 38 with sinus rhythm (Control group), matched for age and sex. The mean ±â€Šstandard deviation age was 73.6 ±â€Š7.2 and 71.6 ±â€Š4.7 years for the AF and control groups, respectively. There were no statistically significant differences in the percentage of systemic hypertension, congestive heart failure, diabetes mellitus type 2, or vascular disease between the groups. Patients were examined for the presence of normal-tension glaucoma (NTG) by an ophthalmologist.NTG was confirmed in 40 patients (34.2%) in the entire group, with 35 (44.3%) in the AF group and 5 (13.15%) in the Control group. The incidence of NTG was significantly higher in the AF group (P = .0221). Women represented 60% of GL patients in the AF group and 80% in the control group. There were no significant differences in intraocular pressure between the groups (mean ±â€Šstandard deviation, 14.3 ±â€Š2.3 vs. 14.2 ±â€Š2.8 mmHg, P = .4202). Approximately three-fourths of patients with AF and NTG had early visual field damage based on the Hodapp classification.AF, independent of other known cardiovascular risk factors, increases the risk of developing NTG. Many AF patients do not have conspicuous symptoms of GL, so understanding the possible risk of its development is critical because early detection might help to prevent later visual impairment and even irreversible blindness.

Human photoreceptor cone density measured with adaptive optics technology (rtx1 device) in healthy eyes: Standardization of measurements.

The anatomic structures of the anterior segment of the eye enable correct reception of stimuli by the retina, which contains receptors that receive light impulses and transmit them to the visual cortex. The aim of this study was to assess the effect of the size of the sampling window in an adaptive optics (AO) flood-illumination retinal camera (rtx1) on cone density measurements in the eyes of healthy individuals and to investigate the differences in cone density and spacing in different quadrants of the retina. Thirty-three subjects with no ophthalmic or systemic disease underwent a detailed ophthalmologic examination. Photographs of retinal fragments 3 degrees from the fovea were taken using the rtx1 AO retinal camera. We used sampling windows with 3 sizes (50 × 50, 100 × 100, and 250 × 250 µm). Cone density, spacing, and shape were determined using AOdetect software. The median (interquartile range) cone density was 19,269 (4964) cones/mm. There were statistically significant differences between measurements taken with the 50/50 and 250/250-m windows. There were no significant differences in the cone spacing results between any of the windows examined, but the measurements differed according to location between the superior and temporal quadrants. The most common cone shape was hexagonal (47.6%) for all window sizes and locations. These findings may help in the development of a normative database for variation in cone density in healthy subjects and to allow the best window to be chosen for obtain the most correct values for eccentricity measurements of 3 degrees. In our study, the optimal sampling window was 100 × 100 µm.

MicroRNAs in glaucoma and neurodegenerative diseases.

MicroRNAs (miRNAs) constitute a class of short, non-coding RNAs, which have important role in post-transcriptional regulation of genes expression by base-pairing with their target messenger RNA (mRNA). In recent years, miRNAs biogenesis, gene silencing mechanism and implication in various diseases have been thoroughly investigated. Many scientific findings indicate the altered expression of specific miRNA in the brains of patients affected by neurodegenerative diseases (NDs) such as Alzheimer's disease, Parkinson's disease and Huntington disease. The progressive optic nerve neuropathy associated with changed miRNA profile was also observed during glaucoma development. This suggests that the miRNAs may have a crucial role in these disorders, contributing to the neuronal cell death. A better understanding of molecular mechanism of these disorders will open a new potential way of ND treatment. In this review, the miRNAs role in particular neurodegenerative disorders and their possible application in medicine was discussed.

Analysis of antioxidative factors related to AMD risk development in the polish patients.

PURPOSE: Age-related macular degeneration (AMD) is a major cause of blindness in developed countries. Oxidative mechanisms may play a key role in the aetiology of AMD. The main aim of this study was to investigate antioxidative markers in the pathogenesis of AMD. METHODS: A total of 510 subjects including 240 patients with AMD (mean age 77.9 ± 8.5 year) and 270 controls (mean age 74.0 ± 10.4 year) were allowed in this study. We measured activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) and examined their association with the SNPs of respective genes (SOD1 + 35A/C, CAT C-262T and GPx Pro197Leu). Restriction fragment length polymorphism (RFLP) technique was used to determine the selected gene polymorphisms. Sixty subjects including 30 patients with AMD (mean age 69.4 ± 9.3) and 30 controls (mean age 64.6 ± 8.2) were enrolled to determine the activity of antioxidant enzymes by spectrometry method. RESULTS: A significant decrease in enzymes, SOD (p = 0.011), CAT (p = 0.002) and GPx (p ≤ 0.001) in AMD patients compared to controls, was indicated. The risk of susceptibility to AMD was significantly higher in patients with AMD who had Pro197Leu C/T genotype of GPx (OR = 2.78; 95% CI = 1.78-4.35). The A/C genotype and the C allele frequencies of A/C polymorphism of SOD1 gene significantly reduce the risk of AMD (OR=0.48; 95% CI 0.27; 0.85). CONCLUSION: In conclusion, our data showed that insufficient antioxidant capacity may have an important role in age-related macular degeneration. The polymorphism of GPx Pro197Leu may reduce the ability to scavenge free radicals in retina and contribute to the development of AMD.

Immunomodulation on the ocular surface: a review.

The increasing understanding of immune mechanisms changed our perception of the ocular surface, which is now considered a compartment of the common mucosal immune system. It offered the possibility to alter the physiological immune response on the ocular surface and effectively combat inflammation, which impairs stability of the tear film and causes tear hyperosmolarity, causing symptoms of dry eye disease. The paper provides an overview of ocular surface anatomy and physiology, explains the underlying mechanisms of dry eye disease and discusses novel and promising treatment modalities, such as cyclosporine A, biological therapies using autologous serum and various growth factors as well as experimental treatment methods which are currently being investigated.

The role of Cat -262C/T, GPX1 Pro198Leu and Sod1+35A/C gene polymorphisms in a development of primary open-angle glaucoma in a Polish population.

The development of glaucoma may be connected with a long-term exposure to oxidative stress caused by free radical (ROS). The main aim of this work was an analysis of associations of Cat-262C/T, GPX1 Pro198Leu and SOD1 35 A/C gene polymorphisms of antioxidant enzymes with a risk of open-angle glaucoma (POAG) in a Polish population. DNA samples collected from 209 patients with POAG and 191 healthy controls were used in this study. Polymorphisms were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). We found that the +35A/C polymorphisms of SOD1 were not associated with a risk of POAG. We found that C/T genotype (1-GPX1Pro198Leu, 2-Cat C262T) is associated with increased risk of open angle glaucoma (1-OR = 2.24; 95% CI: 1.46-3.44; p = 0.0001, 2-OR = 2.16; 95% CI: 1.35-3.34; p = 0.001). We also found that T/T genotype is a risk factor for progression of POAG (1-OR = 3.86; 95% Cl: 1.36-10.96; p = 0.007, 2-OR = 6.37; 95% CI: 1.39-29.28; p = 0.007). Finally our data suggest that gene polymorphisms of GPX1 Pro198Leu and CAT C262T may have a protective role in the development of primary open-angle glaucoma in a Polish population.

Molecular Screening of Keratoconus Susceptibility Sequence Variants in VSX1, TGFBI, DOCK9, STK24, and IPO5 Genes in Polish Patients and Novel TGFBI Variant Identification.

PURPOSE: Keratoconus (KTCN) is a degenerative disorder of the eye that results in the conical shape and thinning of the cornea and is a leading cause for corneal transplantations. A number of studies suggest that genetic factors play a role in KTCN etiology. Some candidate gene variants have recently been shown to be associated with KTCN. The purpose of our study was to verify the role of VSX1, TGFBI, DOCK9, IPO5, and STK24 sequence variants in Polish KTCN patients. METHODS: Forty-two Polish patients with sporadic KTCN and 50 control individuals were enrolled into this study. Both affected and unaffected individuals underwent detailed ophthalmic examination. The mutations screening in the candidate genes was performed by the direct sequencing method. RESULTS: Analysis of VSX1, TGFBI, DOCK9, IPO5, and STK24 genes identified numerous sequence variants. Variants c.-264_-255delGGGGTGGGGT, c.627 + 23G > A, c.809-6_809-5insT, and c.*200G > T in the VSX1 gene, and heterozygous c.1598G > A mutation (Arg533Gln) in exon 12 of TGFBI were detected for the first time in KTCN patients. Two known sequence variants of TGFBI c.1620T > C (Phe540Phe) and c.1678 + 23G > A were observed in KTCN patients and control individuals. The newly reported c.717 + 43A > G substitution in intron 7 of DOCK9 was identified in both KTCN patients and healthy individuals. CONCLUSIONS: Our investigation showed that KTCN-related sequence variants of analyzed genes were found in a very small proportion of the studied patients indicating that genes other than VSX1, TGFBI, DOCK9, IPO5, and STK24 are involved in the development and progression of KTCN in Polish patients. Our results support the hypothesis about the genetic heterogeneity of KTCN.

Next-generation sequencing of ABCA4: High frequency of complex alleles and novel mutations in patients with retinal dystrophies from Central Europe.

Variation in the ABCA4 locus has emerged as the most prevalent cause of monogenic retinal diseases. The study aimed to discover causative ABCA4 mutations in a large but not previously investigated cohort with ABCA4-related diseases originating from Central Europe and to refine the genetic relevance of all identified variants based on population evidence. Comprehensive clinical studies were performed to identify patients with Stargardt disease (STGD, n = 76) and cone-rod dystrophy (CRD, n = 16). Next-generation sequencing targeting ABCA4 was applied for a widespread screening of the gene. The results were analyzed in the context of exome data from a corresponding population (n = 594) and other large genomic databases. Our data disprove the pathogenic status of p.V552I and provide more evidence against a causal role of four further ABCA4 variants as drivers of the phenotype under a recessive paradigm. The study identifies 12 novel potentially pathogenic mutations (four of them recurrent) and a novel complex allele p.[(R152*; V2050L)]. In one third (31/92) of our cohort we detected the p.[(L541P; A1038V)] complex allele, which represents an unusually high level of genetic homogeneity for ABCA4-related diseases. Causative ABCA4 mutations account for 79% of STGD and 31% of CRD cases. A combination of p.[(L541P; A1038V)] and/or a truncating ABCA4 mutation always resulted in an early disease onset. Identification of ABCA4 retinopathies provides a specific molecular diagnosis and justifies a prompt introduction of simple precautions that may slow disease progression. The comprehensive, population-specific study expands our knowledge on the genetic landscape of retinal diseases.

Systemic immunosuppression with mycophenolate mofetil to prevent corneal graft rejection after high-risk penetrating keratoplasty: a 2-year follow-up study.

PURPOSE: In this study, we aimed to evaluate the efficacy and safety of systemic immunosuppression with mycophenolate mofetil (MMF) to prevent corneal graft rejection after high-risk penetrating keratoplasty. METHODS: One hundred and ninety-six consecutive patients who underwent high-risk penetrating keratoplasty defined as the presence of deep vascularization in more than two quadrants, keratouveitis, emergency keratoplasties, and retransplantations were enrolled in the study. Ninety-eight prospectively followed up patients were treated with MMF [with dose adjustment based on mycophenolic acid (MPA) serum concentration], and 98 patients were in the non-MMF-treated retrospectively assessed control group. RESULTS: During a mean of 24 months of observation, immune reactions occurred in eight cases (8 %) and graft rejection with subsequent graft failure occurred in three cases (3 %) in the MMF group. In the control group, graft rejection occurred in 76 cases (78 %) and failure due to graft rejection occurred in 30 cases (31 %). Kaplan-Meier analysis demonstrated that 93 % of the grafts in the MMF-treated group and 47 % in the control group showed no immune rejection (p < 0.01, log-rank test) after a year. Cox regression analysis proved that MMF treatment decreased the risk of graft rejection 11 times (RR = 11, 95.0 % CI 4.8-25, p < 0.0001). Among 98 MMF-treated patients, 13 had gastric discomfort, three developed leucopenia, and two had anemia that resolved after MMF dose reduction. CONCLUSIONS: MMF treatment after high risk penetrating keratoplasty is safe and reduces the incidence of immune graft rejection and graft failure. Side effects were rare and reversible in all but one case.