Multidisciplinary management of patients affected with pseudoxanthoma elasticum / Pseudoxanthoma elasticumban szenvedo betegek multidiszciplináris ellátása

Pseudoxanthoma elasticum (PXE, OMIM # 264800) is an autosomal recessive, multisystemic disorder, associated with mutations of the ABCC6 gene. Ectopic mineralization is in the background of the clinical manifestations of the disease. Calcium-salt crystals are deposited primarily in the skin, in the Bruch membrane of the eyes, and in the vascular endothelium. Thus, in addition to the skin lesions, visual impairment and cardiovascular involvement also occur. Clinical symptoms show varying severity and display heterogeneous appearance. The identification of the phenotype and care of the patients require a multidisciplinary perspective based on the collaboration of a dermatologist, ophthalmologist, cardiologist, and clinical geneticist. The aim of our work is to describe the development of symptoms of the disease, in order to facilitate the diagnosis. In addition, we aim to draw attention to the importance of early diagnosis of pseudoxanthoma elasticum, and to present modern diagnostic methods. Considering the development of severe systemic complications, the early diagnosis with the collaboration between related specialists is crucial to provide optimal clinical care and management of the patients.

Perioperative analgesia of infants during the therapy for retinopathy of prematurity.

BACKGROUND: In this retrospective investigation, we compared the main anesthesiologic aspects in the preoperative, perioperative, and postoperative care of 2 different surgical methods (cryotherapy, laser coagulation) for retinopathy of prematurity. MATERIAL/METHODS: A retrospective analysis of analgesia for retinopathy of prematurity was performed for a 14-year period. Infants treated from January 1994 to December 2007 were involved in the study. Before 1997, we performed transconjunctival cryotherapy with ketamine analgesia for 28 newborn infants, while in the last 10 years, laser photocoagulation was done with nalbuphine-diazepam analgesia in 85 cases. RESULTS: Significant differences were verified in gestational age of birth in the group of retinopathy of prematurity patients treated with cryotherapy compared with those treated with laser coagulation 27.9+/-2.7 weeks vs 26.4+/-2.4 weeks (P<.05). The difference in the need for postoperative ventilation (43% vs 19%; P<.05) as well as the number of cases with hypoxemia (54% vs 21%; P<.05) was significant, compared with the group of infants treated with cryotherapy with those treated with laser coagulation. CONCLUSIONS: This study demonstrates that intravenous analgesia (with ketamine or nalbuphine-diazepam) can be used in the surgical treatment of retinopathy of prematurity.

Truncation of retinoschisin protein associated with a novel splice site mutation in the RS1 gene.

PURPOSE: To present the ocular findings of a Hungarian family with X-linked juvenile retinoschisis (XLRS) and to reveal a novel putative splice mutation leading to serious truncation of retinoschisin (RS1) protein. Our genetic results were compared to a mouse model of XLRS. METHODS: Complete ophthalmic examinations were performed on five members (two male patients, two female carriers, and one healthy fraternal male twin) of the family. The examinations included optical coherence tomography (OCT) and full-field and multifocal electroretinography (mfERG). OCT and ERG results were compared to the normative database of our laboratory. All exons and the flanking intronic regions of the RS1 gene were amplified by polymerase chain reaction and directly sequenced in all family members and in 50 male controls. RESULTS: Typical microcystic foveal changes were found on fundoscopy and OCT in two male patients. Large foveal and smaller perifoveal cysts were detected by OCT in the inner nuclear layer and another deeper retinal cleavage in the photoreceptor layer. The standard combined b-wave amplitudes and b/a amplitude ratios of full-field ERGs of the male patients were decreased compared with controls, but the typical "negative-type" ERG was not observed. The amplitudes of mfERGs were reduced in all rings but mainly in the central part of the examined retina. Implicit times were delayed across almost the whole testing field. Female carriers and the healthy fraternal twin brother were without any symptoms and had normal clinical examination results, but the implicit times of female carriers were delayed in all rings. DNA sequence analyses revealed a novel putative splice mutation (c.78+1G>C) in the splice donor site of intron 2 in RS1 of two male patients and two female carriers. Mutations were absent in the 50 control samples. CONCLUSIONS: Male patients exhibited typical bilateral foveal retinoschisis in two retinal layers and characteristic ERG changes. The inheritance of the novel putative splice mutation (c.78+1G>C) followed the classic inheritance of an X-linked recessive disease in two male patients and two female obligate carriers. There are two possible ways the c.78+1G>C splice site mutation may lead to frameshift and introduce a premature termination codon at the beginning of exon 3: after activation of the next cryptic splice site by a 10 bp insertion or after exon skipping by a 26 bp deletion. The splice site mutation in the second intron of RS1 identified in these XLRS patients is practically identical to the N-ethyl-N-nitrosourea (ENU) induced splice site mutation in the mouse model of XLRS described by the Tennessee Mouse Genome Consortium. The genetic findings of the mutant mouse model confirm and support our human results.

Optical coherence tomography of the macula in congenital achromatopsia.

PURPOSE: It is known that symptoms of congenital achromatopsia are caused by the lack of functioning cones, but there are very few published data on histologic changes in the retina in these cases. This study was conducted to examine in vivo the anatomic structure of the retina of patients with achromatopsia. METHODS: Fifteen eyes of eight patients with congenital achromatopsia and 18 eyes of nine control subjects were examined by optical coherence tomography. Radial 6-mm scans were taken of the macula. The thickness of the neuroretina was measured both automatically and manually. Measurements were taken at the foveola and at distances of 1.5 and 3 mm. Total macular volume and the retinal thickness in the nine ETDRS regions were also calculated. RESULTS: In patients with achromatopsia, statistically significant reductions were found in total macular volume and in the thickness of the central retina. Remarkable differences were found between the results obtained from different methods of measuring retinal thickness. Automated methods underestimated retinal thickness compared with manual measurements. CONCLUSIONS: The structure of the macula in achromats differs from that in normal subjects. A possible reason for the structural alteration is the qualitative and/or quantitative disorder of the cone photoreceptors, as the morphologic change is most expressed in the foveola. The automated methods are not always suitable for measuring retinal thickness in the foveola. The structural changes seen in the central retina of the patients could provide useful information for future gene therapy.

Leber congenital amaurosis: first genotyped Hungarian patients and report of 2 novel mutations in the CRB1 and CEP290 genes.

PURPOSE: To introduce the first Hungarian patients with genetically defined Leber congenital amaurosis (LCA) and to report 2 novel mutations. METHODS: Seven otherwise healthy patients (4-29 years, 5 male and 2 female) who had an onset of severe visual impairment before age 2 years were investigated. The diagnosis was established in all individuals by medical history, funduscopy, and full-field electroretinogram (ERG). Ocular examination included visual acuity testing, digital fundus photography, and in 6 patients retinal imaging with optical coherence tomography (OCT). Arrayed primer extension microarray screening was performed in all probands. In 2 patients, further Sanger sequencing and targeted next-generation sequencing revealed the second disease allele. RESULTS: A cone-rod type LCA was revealed in 4 patients and a rod-cone type disease in 3 patients. Five patients presented with maculopathy. Optical coherence tomography (OCT) imaging showed diffuse retinal thickening in 3 probands with severe macular atrophy in one. Full-field ERGs were undetectable or residual in all patients. Genetic screening revealed AIPL1, CRB1, and CEP290 gene-related pathology in 6 patients; in 1 proband, no mutation was found. Three homozygous and 3 compound heterozygous mutations were identified. Two novel variants were detected: c.2536G>T (p.G846X) in the CRB1 gene and c.4929delA (p.Lys1643fsX2) in the CEP290 gene. CONCLUSIONS: Genetic subtypes identified are among the most common ones in LCA; the phenotypes are consistent with those reported previously. Both novel mutations are predicted to result in a premature translation termination. The phenotype related to the novel CRB1 mutation results in severe atrophic maculopathy.

Mutation Detection in Patients with Retinal Dystrophies Using Targeted Next Generation Sequencing.

Retinal dystrophies (RD) constitute a group of blinding diseases that are characterized by clinical variability and pronounced genetic heterogeneity. The different nonsyndromic and syndromic forms of RD can be attributed to mutations in more than 200 genes. Consequently, next generation sequencing (NGS) technologies are among the most promising approaches to identify mutations in RD. We screened a large cohort of patients comprising 89 independent cases and families with various subforms of RD applying different NGS platforms. While mutation screening in 50 cases was performed using a RD gene capture panel, 47 cases were analyzed using whole exome sequencing. One family was analyzed using whole genome sequencing. A detection rate of 61% was achieved including mutations in 34 known and two novel RD genes. A total of 69 distinct mutations were identified, including 39 novel mutations. Notably, genetic findings in several families were not consistent with the initial clinical diagnosis. Clinical reassessment resulted in refinement of the clinical diagnosis in some of these families and confirmed the broad clinical spectrum associated with mutations in RD genes.

Correlation of clinical and genetic findings in Hungarian patients with Stargardt disease.

PURPOSE: Autosomal recessive Stargardt disease (arSTGD) presents with substantial clinical and genetic heterogeneity. This study was conducted to correlate foveolar thickness (FT) and total macular volume (TMV), measured by optical coherence tomography (OCT), with other clinical characteristics and with specific genetic variation in Hungarian patients with arSTGD. METHODS: After a standard ophthalmic workup, both eyes of 35 patients with STGD from Hungary and of 25 age-matched healthy control subjects were tested with OCT. FT and TMV were measured automatically with the OCT mapping software in the nine Early Treatment Diabetic Retinopathy Study areas of 3500 microm in diameter. All patients were screened for mutations by a combination of the ABCR400 microarray and direct sequencing. RESULTS: The patients with STGD presented with markedly thinned retina in the foveola and decreased macular volume, 72 microm and 1.69 mm3, respectively, compared with 169 microm and 2.48 mm3 in the normal subjects, respectively. Statistically significant correlation was observed between visual acuity (VA) and TMV and between VA and FT. Disease-associated mutations were detected in 23 (65.7%) of 35 patients, including 48.5% with both alleles and 17.2% with one allele. The most frequent ABCA4 alleles in Hungarian patients with STGD were L541P/A1038V (in 28% of all patients), G1961E (20%) and IVS40+5G-->A (17%). Specific genotypes correlated with some phenotypic features and allowed for predictions of the disease progression. CONCLUSIONS: Hungarian patients with STGD presented with extensive foveolar thinning and macular volume loss. Genetic analysis detected several ABCA4 alleles at high frequency in the cohort of patients, suggesting founder effect(s). Unusually homogeneous distribution of disease-associated mutations aided genotype-phenotype correlation analyses in this population.

Laser treatment of zone I prethreshold and stage 3 threshold retinopathy of prematurity.

PURPOSE: To analyze the structural outcomes of zone I prethreshold and stage 3 threshold retinopathy of prematurity following laser ablation. PATIENTS AND METHODS: This nonrandomized observational case series evaluated 71 eyes of 36 infants who weighed less than 1,250 g at birth. Infants were treated at either prethreshold or threshold severity. The structural outcomes were compared using Fisher's exact test. RESULTS: The structural outcome was favorable in 96% and 80% of the prethreshold and threshold groups, respectively (P = .069). When an unfavorable outcome was defined as dragging of the temporal vessels, the difference was significant (P = .0257). CONCLUSION: Early treatment of zone I disease may result in a better structural outcome.

The structure and function of the macula in patients with advanced retinitis pigmentosa.

PURPOSE: To assess the structure and function of the macula in advanced retinitis pigmentosa (RP). METHODS: Twenty-nine eyes of 22 patients with RP were compared against 17 control eyes. Time-domain optical coherence tomography (OCT) data were processed using OCTRIMA (optical coherence tomography retinal image analysis) as a means of quantifying commercial OCT system images. The thickness of the retinal nerve fiber layer (RNFL), ganglion cell layer and inner plexiform layer complex (GCL+IPL), inner nuclear layer and outer plexiform layer complex (INL+OPL), and the outer nuclear layer (ONL) were measured. Multifocal electroretinography (mfERG) was performed; two groups were formed based on the mfERG findings. Fourteen eyes had no detectable central retinal function (NCRF) on mfERG; detectable but abnormal retinal function (DRF) was present in the mfERG of the other 15 eyes. RESULTS: The thickness of the ONL in the central macular region was significantly less in the NCRF eyes compared with that in both DRF eyes and controls. The ONL was significantly thinner in the pericentral region in both patient groups compared with that in controls, whereas the thickness of the GCL+IPL and INL+OPL was significantly decreased only in the NCRF eyes. The RNFL in the peripheral region was significantly thicker, whereas the thickness of the GCL+IPL and ONL was significantly thinner in both patient groups compared with that in controls. CONCLUSIONS: The results are consistent with degeneration of the outer retina preceding inner retinal changes in RP. OCT image segmentation enables objective evaluation of retinal structural changes in RP, with potential use in the planning of therapeutic interventions and conceivably as an outcome measure.

Role of multifocal electroretinography in the diagnosis of idiopathic macular hole.

PURPOSE: To analyze the preoperative results of multifocal electroretinography (mfERG) in the fellow eyes of patients with idiopathic unilateral macular hole and to evaluate the usefulness of this method in predicting the likelihood of macular hole formation in the fellow eye. METHODS: Over a period of 5 years, 80 eyes of 40 patients (mean age, 64.9 years) with unilateral idiopathic macular hole were examined. The diagnosis of idiopathic macular hole was confirmed by optical coherence tomography (OCT). The fellow eyes were intact in all cases. All patients underwent vitreoretinal surgery. Before the surgery, both eyes of the patients were examined by mfERG. During the follow-up period, the 40 fellow eyes were also observed by OCT, and the changes in the vitreofoveal attachment were investigated. The preoperative response densities and ring ratios of mfERG were analyzed in both eyes, and discriminant analysis was used to calculate the best separator function. RESULTS: Preoperative mfERGs demonstrated significantly lower mean response densities in the central area of the 40 eyes with macular hole than in the fellow eyes. During the follow-up period, macular hole was diagnosed in 13 fellow eyes by OCT. The preoperative values of the mfERGs in these eyes were significantly lower than in the other 27 cases. The mfERG ring ratios were significantly lower in the fellow eyes in which macular holes developed than in those that remained intact. CONCLUSIONS: The analysis of ERG in the fellow eyes of patients with macular hole seems clinically useful. The lower amplitude may forecast the propensity for subsequent development of a macular hole. Patients with low central ERG amplitude and lower ring ratios in the healthy fellow eyes should have stricter follow-up.

Association of genetic polymorphisms of vascular endothelial growth factor and risk for proliferative retinopathy of prematurity.

The intention of our retrospective study was to determine whether vascular endothelial growth factor (VEGF) genetic polymorphisms are associated with risk for proliferative retinopathy of prematurity (ROP), a condition that is characterized by abnormal retinal neovascularization and can lead to retinal detachment and result in blindness. We enrolled 86 very low birth weight infants (birth weight < or =1500 g) who had been treated with cryo/laser therapy because of the risk for proliferative ROP (treated group). Their VEGF T-460C and G+405C genotypes were determined from dried blood samples and were compared with VEGF genotypes of 115 VLBW infants who were not treated with cryo/laser therapy (untreated group). We found that the allele frequency of VEGF +405C was higher in the treated group than in the untreated group (0.30 versus 0.41; p <0.05). The likelihood of being treated for ROP was higher in heterozygous and homozygous carriers of VEGF +405C alleles [odds ratios adjusted for risk factors of ROP (95% CI): 2.00 (1.02-3.92; p=0.04) and 3.37 (1.17-9.65; p=0.007), respectively]. VEGF -460TT/+405CC haplotype was more prevalent in the treated patients than in the untreated patients (13 of 86 versus 1 of 115; p <0.001), and the association remained significant (p <0.01) even after the adjustment for risk factors of ROP (gestational age, supplemental oxygen therapy, and gender). These findings suggest that the VEGF genotype may be associated with risk for proliferative ROP in VLBW infants.

Utilization of lacrimal urea assay in the monitoring of hemodialysis: conditions, limitations and lacrimal arginase characterization.

The lacrimal urea content was found to be proportional to that of blood, which suggested its possible utilization in the monitoring of hemodialysis as a less invasive method. On the other hand, however, arginase activity was detected in tears, which may influence the urea content independently of blood urea concentration. The feasibility of using lacrimal urea measurement to replace blood urea measurement in the monitoring hemodialysis was also investigated. Blood and tear samples of 35 healthy persons and 43 renal patients undergoing hemodialysis were tested. Tear samples were collected on Schirmer paper strips. After elution the lacrimal urea content was measured by a colorimetric method. The determination of arginase activity was based on the release of urea and ornithine. The correlation between blood and lacrimal urea and arginase was studied by multivariate regression analysis. The lacrimal arginase isoenzyme pattern was investigated by native polyacrylamide gel electrophoresis and Western blotting. The effect of partially isoform-specific inhibitors was also studied. Blood urea levels in blood were significantly higher in the renal patients before dialysis than in the control patients (12.86 +/- 0.59 vs. 6.45 +/- 0.41 mM, p < 0.0001). Blood sera arginase activity was very low. Lacrimal arginase activity was significantly higher in tears than in sera (p < 0.0001 for each group). The tear/serum ratio of urea content was significantly different between controls and renal patients, particularly in postdialytic samples (1.89 +/- 0.07 vs. 3.49 +/- 0.31, p < 0.0001). The correlation between lacrimal and blood sera urea was best in controls (r = 0.89) and was better in predialytic (r = 0.75) than in postdialytic (r = 0.52) samples, depending on the level of arginase activity. In postdialytic samples a stronger correlation (r = 0.77) between tear urea and arginase was observed. Both arginase isoforms were detected in tears, but the extrahepatic (arginase II) isoenzyme was present in higher concentration. In conclusion, the determination of lacrimal urea level as a possible less invasive replacement for blood urea determination could only be utilized in the monitoring of hemodialysis if lacrimal arginase is also measured. Blood urea levels can be correctly determined by using equations, which take into account arginase activity. The accuracy of these equations was checked on a new patient population. Both arginase isoenzymes were observed in lacrimal samples.