[10 years of screening for retinopathy of prematurity (2009-2019) : Results analysis of two German level-1 neonatal intensive care units (NICUs) with university on-site screening and a telemedical approach in the non-university NICU]. / 10 Jahre Screening auf Frühgeborenenretinopathie (2009­2019) : Ergebnisanalyse zweier deutscher Level-1-Perinatalzentren mit universitärem Vor-Ort-Screening und telemedizinischem Ansatz in dem nicht universitären Zentrum.

BACKGROUND: Retinopathy of prematurity (ROP) is one of the most common causes of childhood blindness in Germany and worldwide and adequate screening is essential. The telemedical approach with objective documentation of retinal findings opens up the possibility of reliably diagnosing all ROP stages independent of the examiner, if a team of ophthalmologists specialized in ROP evaluates the images. OBJECTIVE: A 10-year comparison of ROP screening at two level­1 neonatal intensive care units (NICU): university and on-site vs. non-university and telemedical. MATERIAL AND METHODS: Retrospective analysis of screened premature infants by gestational age (GA), birth weight (BW), sex, multiple births, time of ROP occurrence, treatment needs and time as well as examination frequency. RESULTS: From 2009 to 2019, we screened 1191 infants of whom 29 had been screened before by an external clinic. The internal 1162 infants were screened on-site with 3713 retinal examinations. We diagnosed 34% with ROP and treated 5.4% (3.7% in Giessen, 7.2% in Siegen). Mean GA was 28.9 weeks (±â€¯2.5 weeks); mean BW 1155 g (±â€¯417.5 g). The number of ROP diagnoses increased by 227.3% in Giessen and by 111.1% in Siegen due to the increasing number of premature births in neonatal care. CONCLUSION: Comparative analysis confirmed nationally and internationally increasing ROP screening and children with acute ROP. Telemedical screening was equivalent to on-site screening and safe. Both screening methods identified infants requiring treatment on time. No child with GA > 29 weeks required treatment, analogous to Swedish ROP registry results; however, in the German ROP registry some premature babies with GA ≥ 30 weeks required treatment.

CEP162 deficiency causes human retinal degeneration and reveals a dual role in ciliogenesis and neurogenesis.

Defects in primary or motile cilia result in a variety of human pathologies, and retinal degeneration is frequently associated with these so-called ciliopathies. We found that homozygosity for a truncating variant in CEP162, a centrosome and microtubule-associated protein required for transition zone assembly during ciliogenesis and neuronal differentiation in the retina, caused late-onset retinitis pigmentosa in 2 unrelated families. The mutant CEP162-E646R*5 protein was expressed and properly localized to the mitotic spindle, but it was missing from the basal body in primary and photoreceptor cilia. This impaired recruitment of transition zone components to the basal body and corresponded to complete loss of CEP162 function at the ciliary compartment, reflected by delayed formation of dysmorphic cilia. In contrast, shRNA knockdown of Cep162 in the developing mouse retina increased cell death, which was rescued by expression of CEP162-E646R*5, indicating that the mutant retains its role for retinal neurogenesis. Human retinal degeneration thus resulted from specific loss of the ciliary function of CEP162.

RETINAL VASCULAR DEVELOPMENT WITH 0.312 MG INTRAVITREAL BEVACIZUMAB TO TREAT SEVERE POSTERIOR RETINOPATHY OF PREMATURITY: A Longitudinal Fluorescein Angiographic Study.

PURPOSE: To report the outcome of intravitreal 0.312 mg bevacizumab (IVB) monotherapy in acute retinopathy of prematurity (ROP) and to describe the vascular development over time. METHODS: Seventeen prematurely born infants were treated with IVB (0.312 mg in 0.025 mL per eye) because of acute ROP in posterior Zone II or Zone I, including aggressive posterior ROP. Infants were examined by fluorescein angiography (FA) using RetCam II or III (Clarity Medical Systems Inc) before IVB (n = 21 eyes), within 6 weeks (n = 23 eyes), 8 to 13 weeks (n = 22 eyes), and up to 45 months (n = 10 eyes). RESULTS: Acute ROP regressed in 19 out of 27 analyzed eyes (70%), including 100% and 80% of posterior Zone II and Zone I eyes, respectively, but only 25% of aggressive posterior ROP eyes. Early recurrences (11%, all aggressive posterior ROP) and late reactivations (18%) were observed within 1 week and at 9 to 12 weeks, respectively. All eyes showed leakage at the junction of the vascularized zone and capillary malformation on FA before treatment. Vessel branching abnormalities and circumferential vessel formation were typical FA features after treatment. Vascular outgrowth after one IVB became complete in 87.5% of eyes for which FA was available up to at least 9 weeks after IVB. CONCLUSION: A single dose of 0.312 mg bevacizumab was efficient to induce regression of ROP in posterior Zone II and most of Zone I cases, but not in aggressive posterior ROP. FA describes vascular abnormalities, the importance of which warrants further investigation.

Ocular morphology and function in juvenile neuronal ceroid lipofuscinosis (CLN3) in the first decade of life.

PURPOSE: CLN3 is a rare lysosomal storage disorder. The majority of the patients suffer from neurological degeneration in the first decade of life leading to death in the second or third decade. One of the first symptoms is a rapid visual decline from retinal degeneration. The aim of this study was to correlate the retinal changes in CLN3 as seen with spectral domain optical coherence tomography (SD-OCT) with functional data in patients in the first years after the subjective onset of ocular symptoms. METHODS: Three unrelated children aged from 5.6 to 8.8 years, and with molecularly confirmed CLN3, underwent a comprehensive ophthalmological examination including visual acuity, fundus photography, fundus autofluorescence (FAF), electrophysiology (multifocal ERG), Goldmann visual fields, and SD-OCT. RESULTS: A predominant loss of the first and second neuron retinal layers progressing from the macula to the periphery was identifed. The retinal nerve fibre layer (RNFL) displayed gliosis and an irregular lining of the inner limiting membrane. Compared to the preferential reduction of photoreceptor layer thickness in other maculopathies with pan-retinal involvement, the thickness of the first and second neuron layers was reduced simultaneously in CLN3. Functional testing by multifocal ERG reflected the degenerative progress. Semiquantitative evaluation revealed a generally reduced FAF. CONCLUSION: This is the first detailed morphological evaluation of CLN3 patients in the first years after the subjective onset of ocular symptoms. CLN3 is characterized by an early degeneration predominant of the first and second neuron compared to other macular and generalized retinal dystrophies. Imaging is instrumental for early diagnosis and gene-directed molecular analysis of this fatal disorder.

Normative values of peripheral retinal thickness measured with Spectralis OCT in healthy young adults.

BACKGROUND: To evaluate the range of peripheral retinal thickness (PRT) in young healthy human subjects by Spectralis HRA + OCT, and to analyze a potential association between the peripheral location, spherical equivalent (SE), axial length (AL), and gender. METHODS: After pupil dilation, the peripheral retina was scanned by means of six volume protocols (9 × 7.5 mm), each consisting of 31 B-scans. PRT was determined at 4,500, 5,500, 6,500 and 7,500 µm eccentricity from the fovea and the optic nerve head (ONH). Data points were collected every 22.5°. Six additional data points at a distance of 9,000 µm were included. In 11 subjects, OCT measurements were performed twice to evaluate reproducibility. Coefficients of variation (COV) were calculated. RESULTS: Randomly selected eyes of 50 subjects (19-30 years) with AL of 21-27 mm (SE: -5.75 to +5.25 dpt) were included in the study. Mean PRT decreased significantly (p ≤ 0.001, r = -0.99) towards the periphery, reaching a minimum at 9,000 µm eccentricity (mean PRT: 187.7 ± 8.9 µm). Multiple regression analysis revealed a significant association of PRT with AL at nasal and temporal locations as well as gender for temporal locations. COVs ranged from 0.44 to 2.90 %, with highest COVs found nasal to the fovea. CONCLUSIONS: This is the first study to report normative data of PRT outside the ETDRS grid and to show a significant continuous almost linear decrease of the RT from the center into the periphery. The data will be valuable to detect peripheral pathologies of the retina in early stages of peripheral retinal dystrophies.

Improving detection of mild loss of retinal light increment sensitivity at the posterior pole with the microperimeter MP1.

PURPOSE: With "standard" stimuli (white, Goldmann size III, 200 ms), the Nidek Microperimeter MP1 underestimates retinal light increment sensitivity (LIS). We thoroughly analyze this problem, suggest alternative settings to improve sensitivity to detect dysfunction, and provide true normal values. METHODS: LIS was tested at 55 positions in the macular region using a 4-2-1 staircase strategy with 200 ms white or red stimuli on a 1.3 cd m⁻² background. Stimulus size was Goldmann III and I, and additionally II in the healthy subjects. All participants underwent a complete ophthalmologic examination, spectral domain optical coherence tomography (OCT), and fundus autofluorescence (FAF). RESULTS: In normals, distributions of LIS for white Goldmann sizes II and III within the central 6° to 10° were clipped off at 20 dB--the MP1 cannot attenuate them any further. When the stimulus size was reduced to Goldmann I or the color changed to red, median LIS in the fovea (∼15 dB) was approximately 5 dB higher than at 10° eccentricity. Estimated from these results, central LIS for white Goldmann sizes II and III stimuli were 21 and 27 dB, respectively. In four patients with either focal or diffuse macular pathology, as confirmed by funduscopy, OCT, or FAF, reduced LIS was detected clearly with Goldmann size I stimuli, but not III. CONCLUSIONS: In all subjects reported here, standard central LIS was above the technical limit of the MP1. To measure true thresholds in healthy subjects, either smaller (Goldmann size I) or dimmer stimuli (red) must be used.

PTBP1 is required for embryonic development before gastrulation.

Polypyrimidine-tract binding protein 1 (PTBP1) is an important cellular regulator of messenger RNAs influencing the alternative splicing profile of a cell as well as its mRNA stability, location and translation. In addition, it is diverted by some viruses to facilitate their replication. Here, we used a novel PTBP1 knockout mouse to analyse the tissue expression pattern of PTBP1 as well as the effect of its complete removal during development. We found evidence of strong PTBP1 expression in embryonic stem cells and throughout embryonic development, especially in the developing brain and spinal cord, the olfactory and auditory systems, the heart, the liver, the kidney, the brown fat and cartilage primordia. This widespread distribution points towards a role of PTBP1 during embryonic development. Homozygous offspring, identified by PCR and immunofluorescence, were able to implant but were arrested or retarded in growth. At day 7.5 of embryonic development (E7.5) the null mutants were about 5x smaller than the control littermates and the gap in body size widened with time. At mid-gestation, all homozygous embryos were resorbed/degraded. No homozygous mice were genotyped at E12 and the age of weaning. Embryos lacking PTBP1 did not display differentiation into the 3 germ layers and cavitation of the epiblast, which are hallmarks of gastrulation. In addition, homozygous mutants displayed malformed ectoplacental cones and yolk sacs, both early supportive structure of the embryo proper. We conclude that PTBP1 is not required for the earliest isovolumetric divisions and differentiation steps of the zygote up to the formation of the blastocyst. However, further post-implantation development requires PTBP1 and stalls in homozygous null animals with a phenotype of dramatically reduced size and aberration in embryonic and extra-embryonic structures.

Interchangeability of macular thickness measurements between different volumetric protocols of Spectralis optical coherence tomography in normal eyes.

BACKGROUNDS: To evaluate in healthy eyes the interchangeability of retinal thickness measurements resulting from different protocols of Spectralis optical coherence tomography (OCT, Heidelberg Engineering, Germany). METHODS: Three different central volumetric protocols were performed in one session by one single operator in a randomly selected eye of 31 healthy adults (range, 19-30 years): (1) area 6 × 6 mm, 25 scan pattern (SP), (2) area 6 × 6 mm, 49 SP, (3) area 6 × 3 mm, 97 SP. Nine ETDRS areas were analyzed, except outer areas for 97 SP. Interclass correlation coefficients (ICC) and limits of agreement (Bland-Altman) were calculated. RESULTS: Mean minimal foveal thickness was 224.0 ± 15.8 µm and central retinal thickness 280.8 ± 16.5 µm. ICC ranged from 0.973 to 0.993. Ninety-five percent limits of agreement between the protocols were <7 µm in all ETDRS areas. The difference between two measurements never exceeded 9 µm. CONCLUSIONS: Spectralis OCT retinal thickness measurements in healthy subjects showed good protocol interchangeability for all tested protocols. Larger differences are to be expected in eyes with macular pathology.

Impaired insulin turnover in islets from type 2 diabetic patients.

Failure of pancreatic ß-cells contributes to the development of type 2 diabetes. Besides evidence of reduced glucose-stimulated insulin secretion and ß-cell mass, little information is available about the molecular deficits of human diabetic islets. Islets were isolated from macroscopically normal pancreatic tissue from 8 patients with type 2 diabetes and 17 matched non-diabetic patients who underwent pancreatic surgery. Insulin content and insulin secretion were measured before and after islet stimulation with 25 mM glucose for 2 hours. In parallel, we also investigated the subcellular localization of polypyrimidine tract-binding protein 1 (PTBP1), whose nucleocytoplasmic translocation is involved in the rapid posttranscriptional up-regulation of insulin biosynthesis following islet stimulation with glucose and GLP-1. Glucose stimulated insulin secretion was decreased, albeit not significantly, in type 2 diabetic islets compared to non-diabetic islets. Stimulation increased the total amount of insulin (islet insulin content + secreted insulin) in islet preparation from non-diabetic patients, but not from type 2 diabetic subjects. Furthermore, the nuclear levels of PTBP1 were decreased in stimulated non-diabetic islets, but not in type 2 diabetic islets. These results suggest that impairment of rapid insulin increase in response to glucose is a specific trait of type 2 diabetic islets. Nuclear retention of PTBP1 is likely to play a role in this deficit, which in turn can contribute to impaired insulin secretion in type 2 diabetes. Overall, these data highlight the importance of investigating mechanisms of insulin biosynthesis and degradation to gain insight into the pathogenesis of type 2 diabetes.

ß2-Syntrophin is a Cdk5 substrate that restrains the motility of insulin secretory granules.

The molecular basis for the interaction of insulin granules with the cortical cytoskeleton of pancreatic ß-cells remains unknown. We have proposed that binding of the granule protein ICA512 to the PDZ domain of ß2-syntrophin anchors granules to actin filaments and that the phosphorylation/dephosphorylation of ß2-syntrophin regulates this association. Here we tested this hypothesis by analyzing INS-1 cells expressing GFP-ß2-syntrophin through the combined use of biochemical approaches, imaging studies by confocal and total internal reflection fluorescence microscopy as well as electron microscopy. Our results support the notion that ß2-syntrophin restrains the mobility of cortical granules in insulinoma INS-1 cells, thereby reducing insulin secretion and increasing insulin stores in resting cells, while increasing insulin release upon stimulation. Using mass spectrometry, in vitro phosphorylation assays and ß2-syntrophin phosphomutants we found that phosphorylation of ß2-syntrophin on S75 near the PDZ domain decreases its binding to ICA512 and correlates with increased granule motility, while phosphorylation of S90 has opposite effects. We further show that Cdk5, which regulates insulin secretion, phosphorylates S75. These findings provide mechanistic insight into how stimulation displaces insulin granules from cortical actin, thus promoting their motility and exocytosis.

cAMP-dependent phosphorylation of PTB1 promotes the expression of insulin secretory granule proteins in beta cells.

Glucose stimulates the exocytosis of insulin secretory granules of pancreatic beta cells. Granule stores are quickly refilled by activation of posttranscriptional mechanisms that enhance the biosynthesis of granule components. Rapid replacement of granules is important to sustain insulin secretion, since new granules appear to be preferentially released. Posttranscriptional regulation of granule biogenesis includes the glucose-induced nucleocytoplasmic translocation of polypyrimidine tract binding protein 1 (PTB1), which binds mRNAs encoding granule proteins, and thus promotes their stabilization and translation. Glucagon-like peptide 1 (GLP-1) potentiates glucose-stimulated insulin gene expression and secretion by increasing cAMP levels in beta cells. Here, we show that elevation of cAMP levels causes the protein kinase A-dependent phosphorylation and nucleocytoplasmic translocation of PTB1, thereby preventing the rapid degradation of insulin mRNA and enhancing the expression of various granule proteins. Taken together, these findings identify PTB1 as a common downstream target of glucose and GLP-1 for the posttranscriptional upregulation of granule biogenesis.

Effect of oxygenated perfluorocarbons on isolated rat pancreatic islets in culture.

One impediment for a wider application of islet transplantation is the limited number of donor pancreata for islet isolation. A more efficient utilization of available organs could in part alleviate this problem. Perfluorocarbons (PFCs) have a high oxygen solubility coefficient and maintain high oxygen partial pressures for extended time. They serve also as oxygen "reservoirs" for harvested organs in pancreas organ transplantation. The aim of this study was to test whether the use of PFCs could also be beneficial for the secretory activity and overall viability of cultured purified islets before transplantation. Purified rat islets were cultured in static conditions with or without oxygen-saturated PFCs for 1 or 7 days. Cell death and apoptosis were assessed by trypan blue staining, DNA strand breaks, and caspase 3/7 activity. mRNA levels of insulin and ICA512/IA-2, a membrane marker of secretory granules (SGs), were quantitated by real-time PCR, whereas insulin content and secretion were measured by RIA. Polypyrimidine tract binding protein (PTB), which promotes SG biogenesis, was assessed by Western blotting. The number of SGs and the ultrastructural appearance of beta5-cells were analyzed by cryoimmunoelectronmicroscopy for insulin. Various parameters, including caspase activity, insulin and ICA512/IA-2 mRNA levels, PTB expression, number of secretory granules, and ultrastructural appearance did not significantly differ between control and PFC-cultured islets. On the other hand, PFC culture islets showed significantly increased DNA fragmentation and a reduced insulin stimulation index at both time points compared to control islets. While advantageous for the transport of human harvested organs, the use of PFH in the culture may be comparable to and/or not provide advantage over conventional protocols for culture of islets for transplantation.

Continuous retrobulbar anesthesia for scleral buckling surgery using an ultra-fine spinal anesthesia catheter.

PURPOSE: To evaluate a novel retrobulbar catheter technique for intraoperative and postoperative analgesia in patients undergoing scleral buckling procedures. METHODS: This prospective noncomparative clinical interventional case-series study included 43 consecutive patients undergoing scleral buckling procedures as treatment of rhegmatogenous retinal detachments. Using a commercially available retrobulbar needle with a diameter of 0.80 mm and a length of 38 mm, 7 mL of local anesthetic were injected into the retrobulbar space. Through the same needle, a 28-gauge commercially available flexible spinal anesthesia catheter was introduced into the retrobulbar space, the needle was withdrawn, and the catheter was fixed. The catheter was removed on the morning of the first postoperative day. When the patients started to feel pain during or after surgery, 2 mL of local anesthetic were re-injected through the catheter. RESULTS: During surgery, 12 (27.9%) patients received a pain-free re-injection through the retrobulbar catheter resulting in a marked reduction of pain. Two (4.7%) patients needed a second re-injection. In the postoperative period, 23 (53.5%) patients experienced pain of grade 3 or higher 5.4 +/- 6.7 hr after start of surgery and received a retrobulbar re-injection. Eleven (25.6%) patients asked for a second postoperative re-injection, and four (9.3%) patients received a third postoperative re-injection. Cardiopulmonary and central nervous adverse effects were not noticed. CONCLUSIONS: Use of an ultra-fine retrobulbar catheter for repeat intraoperative and postoperative injections of local anesthetics is a simple and effective method to achieve analgesia during and after scleral buckling procedures.

Retrobulbar catheter technique for postoperative titratable analgesia after glaucoma surgery.

PURPOSE: To assess an indwelling retrobulbar catheter for delivery of intraoperative anesthesia and postoperative analgesia in patients undergoing painful cyclodestructive and retinal destructive procedures as treatment of neovascular glaucoma. PATIENTS AND METHODS: The prospective clinical interventional study included all 11 patients undergoing cyclocryocoagulation and/or retinal exocryocoagulation as treatment of neovascular glaucoma due to proliferate ischemic retinopathies. Using a commercially available retrobulbar needle with a diameter of 0.80 mm and a length of 38 mm, 7 mL of a local anesthetic were injected. Through the same needle, a 28-gauge commercially available flexible catheter was introduced into the retrobulbar space, the needle was withdrawn, and the catheter was fixed in place. When the patients began to feel pain during or after surgery, 2 mL of a local anesthetic were reinjected through the catheter. The catheter was removed 24 hours after surgery. RESULTS: Due to increasing pain in the postoperative period, 8 (72.7%) patients received a reinjection 156.3 +/- 94.6 minutes after the preoperative injection. Seven (63.6%) patients requested a second reinjection 268.6 +/- 45.7 minutes after the preoperative injection, and three (27.3%) patients requested a third postoperative injection 333.3 +/- 79.1 minutes after the preoperative injection. Reinjection of the local anesthetic through the catheter markedly decreased the pain within 5 minutes of injection in all patients. CONCLUSIONS: Avoiding side effects of systemic analgesics and sedatives, an indwelling retrobulbar catheter for repeat postoperative injections of local anesthetics is useful and effective for titratable postoperative analgesia after painful cyclodestructive or retinal destructive surgery as treatment of neovascular glaucoma.