Case report: A rare case of bilateral Leber's idiopathic stellate neuroretinitis.

Background: Leber's idiopathic stellate neuroretinitis (LISN) is a rare disease characterized by disk edema, peripapillary and macular hard exudates, and often, the presence of vitreous cells. To enhance clinical understanding of the disease, a retrospective analysis was conducted on a patient diagnosed with LISN at our hospital, and discussions were held regarding its diagnosis and treatment. Methods: We reviewed the medical records of a 26-year-old male patient whose main complaint was a decrease in visual acuity of both eyes for 4 days, which had worsened over the last day. After systemic examination, fundus fluorescein angiography, and indocyanine green angiography, the patient was diagnosed with LISN in both eyes. After treatment with glucocorticoids, the patient's vision showed a significant improvement. Results: Upon admission, the visual acuity of both eyes was: VOD 0.05, VOS 0.25. After 5 days of treatment, the visual acuity of both eyes was: VOD 0.25, VOS 0.4. After 1 month of follow-up, the visual acuity of both eyes was: VOD 0.4, VOS 0.6. After 5 months of follow-up, the patient's vision improved to VOD 0.6, VOS 0.8. Conclusion: The cause of LISN remains unidentified. It is essential to rule out diseases exhibiting similar clinical signs but possessing a clear etiology. The primary treatment approach involves glucocorticoid-based anti-inflammatory therapy, potentially supplemented with antibiotics, antivirals, vasodilators, and traditional Chinese medicine. This disease is usually self-limiting and generally carries a favorable prognosis.

Early changes to retinal structure in patients with diabetic retinopathy as determined by ultrawide swept-source optical coherence tomography-angiography.

Purpose: To investigate retinal vascular changes in patients with diabetic retinopathy (DR) using the newly developed ultrawide rapid scanning swept-source optical coherence tomography angiography (SS-OCTA) device. Methods: This cross-sectional, observational study enrolled 24 patients (47 eyes) with DR, 45 patients (87 eyes) with diabetes mellitus (DM) without DR, and 36 control subjects (71 eyes). All subjects underwent 24 × 20 mm SS-OCTA examination. Vascular density (VD) and the thickness of the central macula (CM; 1 mm diameter) and temporal fan-shaped areas of 1-3 mm (T3), 3-6 mm (T6), 6-11 mm (T11), 11-16 mm (T16), and 16-21 mm (T21) were compared among groups. The VD and the thicknesses of the superficial vascular complex (SVC) and deep vascular complex (DVC) were analyzed separately. The predictive values of VD and thickness changes in DM and DR patients were evaluated by receiver operating characteristic (ROC) curve analysis. Results: The average VDs of the SVC in the CM and the T3, T6, T11, T16, and T21 areas were significantly lower in the DR than in the control group, whereas only the average VD of the SVC in the T21 area was significantly lower in the DM group. The average VD of the DVC in the CM was significantly increased in the DR group, whereas the average VDs of the DVC in the CM and T21 area were significantly decreased in the DM group. Evaluation of the DR group showed significant increases in the thicknesses of SVC-nourishing segments in the CM and T3, T6, and T11 areas and significant increases in the thicknesses of DVC-nourishing segments in the CM and T3 and T6 areas. In contrast, none of these parameters showed significant changes in the DM group. ROC curve analysis showed that the average VD of the SVC in the CM, T3, and T21 had better ability to predict DR, with areas under the ROC curves (AUCs) of 0.8608, 0.8505, and 0.8353, respectively. The average VD of the DVC in the CM was also predictive of DR, with an AUC of 0.8407. Conclusions: The newly developed ultrawide SS-OCTA device was better able to reveal early peripheral retinal vascular changes than traditional devices.

Age-related macular degeneration: Epidemiology, genetics, pathophysiology, diagnosis, and targeted therapy.

Age-related macular degeneration (AMD) is a complex eye disorder and is the leading cause of incurable blindness worldwide in the elderly. Clinically, AMD initially affects the central area of retina known as the macula and it is classified as early stage to late stage (advanced AMD). The advanced AMD is classified into the nonexudative or atrophic form (dry AMD) and the exudative or neovascular form (wet AMD). More severe vision loss is typically associated with the wet form. Multiple genetic factors, lipid metabolism, oxidative stress and aging, play a role in the etiology of AMD. Dysregulation in genetic to AMD is established to 46%-71% of disease contribution, with CFH and ARMS2/HTRA1 to be the two most notable risk loci among the 103 identified AMD associated loci so far. Chronic cigarette smoking is the most proven consistently risk living habits for AMD. Deep learning algorithm has been developed based on image recognition to distinguish wet AMD and normal macula with high accuracy. Currently, anti-vascular endothelial growth factor (VEGF) therapy is highly effective at treating wet AMD. Several new generation AMD drugs and iPSC-derived RPE cell therapy are in the clinical trial stage and are promising to improve AMD treatment in the near future.

A new application of aptamer: One-step purification and immobilization of enzyme from cell lysates for biocatalysis.

Aptamers are nucleic acid-based high affinity ligands that are able to capture their corresponding target through molecular recognition. In this study, several DNA aptamers with high affinity and specificity for ß-glucuronidases (PGUS-E) were obtained by our modified SELEX method. Among them, Apt5 and Apt9 were selected as representatives and covalently linked to magnetic beads, respectively. The aptamer-modified magnetic beads were characterized and successfully applied to one-step purification and immobilization of PGUS-E from the complex cell lysates. By conveniently adjusting the pH and ion strength, the PGUS-E purities reached 84% for Apt5-modified beads and 88% for Apt9-modified beads. Moreover, the maximum PGUS-E capturing capacity of the Apt5 and Apt9 modified magnetic beads were found to be 31.75µg/mg and 32.95µg/mg, respectively. The immobilized PGUS-E on aptamer-based magnetic beads showed good reusability, and the conversion of glycyrrhizin still remained more than 70% after 7 cycles. In addition, the aptamer-modified beads support can be easily regenerated, and the conversion rate of glycyrrhizin (GL) was still 62% after the 7th cycle of regeneration. This investigation can be easily extended to other enzyme systems and may help open a generic route to develop a novel enzyme immobilization technology for biocatalysis based on aptamer.

Time-dependent expression of PEDF and VEGF in blood serum and retina of rats with oxygen-induced retinopathy.

The effects of the balance changes of pigment epithelium growth factor (PEDF) and vascular endothelial growth factor (VEGF) in whole-body and retinal tissue on rats with oxygen-induced retinopathy were investigated. Forty-eight neonatal SD rats at the age of 7 days were randomly divided into 4 groups. The neonatal rats in experimental groups were exposed to 75% to 80% oxygen for 5 days and then to normal air, and those in control groups were kept feeding in normal air. At the age of 17 and 22 days, all the neonatal rats received retina angiography with FITC-dextran and the pathological changes of retinal vessels and perfusion were observed. HE staining of the tissue section and the number counting of endothelial cells extending beyond the inner limiting membrane were performed to evaluate the endothelial proliferation. Immunohistochemistry was applied to detect the expression of PEDF and VEGF in retinal tissue, and ELISA to detect their expression in serum. A hypoxic-ischemic proliferation of retina and more endothelial cells extending beyond the inner limiting membrane were found in the neonatal rats in both experimental groups of 17-day old and 22-day old as compared with those in control group with the difference being statistically significant (P<0.01). VEGF staining of the rats in the 17-day old experimental group was significantly stronger, with an increasing positive rate, than that of the rats in the 17-day old control group (P<0.01). PEDF staining of the rats of 22 days old was weaker than that of the rats of 17 days old in the experimental groups (P<0.01). There was no significant difference in serum VEGF concentration among all groups (P>0.05). The serum PEDF concentration in the rats of 17 days old in experimental group was decreased significantly as compared with that in the rats of 17 days old in control group (P<0.01), and in experimental groups, the serum PEDF concentration of the rats of 22 days old was increased as compared with that of the rats of 17 days old (P<0.01). In conclusion, the obviously decreased serum PEDF concentration and the abnormal enhanced expression of VEGF density in local retinal tissue broke down the balance of PEDF/VEGF in whole-body or local tissues, which might play an important role in retinal vascular proliferation.

A novel PRPF31 mutation in a large Chinese family with autosomal dominant retinitis pigmentosa and macular degeneration.

PURPOSE: This study was intended to identify the disease causing genes in a large Chinese family with autosomal dominant retinitis pigmentosa and macular degeneration. METHODS: A genome scan analysis was conducted in this family for disease gene preliminary mapping. Snapshot analysis of selected SNPs for two-point LOD score analysis for candidate gene filter. Candidate gene PRPF31 whole exons' sequencing was executed to identify mutations. RESULTS: A novel nonsense mutation caused by an insertion was found in PRPF31 gene. All the 19 RP patients in 1085 family are carrying this heterozygous nonsense mutation. The nonsense mutation is in PRPF31 gene exon9 at chr19:54629961-54629961, inserting nucleotide "A" that generates the coding protein frame shift from p.307 and early termination at p.322 in the snoRNA binding domain (NOP domain). CONCLUSION: This report is the first to associate PRPF31 gene's nonsense mutation and adRP and JMD. Our findings revealed that PRPF31 can lead to different clinical phenotypes in the same family, resulting either in adRP or syndrome of adRP and JMD. We believe our identification of the novel "A" insertion mutation in exon9 at chr19:54629961-54629961 in PRPF31 can provide further genetic evidence for clinical test for adRP and JMD.

[Rapid assessment of avoidable blindness cataract in country Anyue in Sichuan Province].

OBJECTIVE: To explore the prevalence of cataract and measure the outcomes after cataract surgery in patients aged ≥ 50 years and to evaluate the validity of Rapid Assessment of Avoidable Blindness (RAAB). METHODS: A total of 76 clusters of 50 patients aged ≥ 50 years were selected through probability proportionate to size sampling. The measurements of visual acuity (VA) were made with a tumbling-E chart and the diagnosis of the principal cause of visual impairment by an ophthalmologist. RESULTS: A total of 3288 patients were examined with a response rate of 86.5%. There were 271 males (38.7%) and 2017 females (61.3%). Among 832 cataract patients, 175 (5.3%) had blindness due to cataract. The prevalence of cataract was 9.2%, 25.2%, 47.6%, 70.1% in 50, 60, 70, 80 years old respectively. And 109 eyes underwent cataract surgery. Among 88 pseudophakic eyes (80.7%), 59 eyes achieved excellent outcomes (VA ≥ 0.3) after surgery (54.1%). CONCLUSION: The major cause of blindness in Anyue is due to cataract. Attention needs to be paid to improving outcomes after surgery. RAAB provides information about the magnitude and cause of avoidable blindness so that it may be used for planning and monitoring cataract.

[Gas pipeline leak detection based on tunable diode laser absorption spectroscopy].

The principle of tunable diode laser absorption spectroscopy and harmonic detection technique was introduced. An experimental device was developed by point sampling through small multi-reflection gas cell. A specific line near 1 653. 7 nm was targeted for methane measurement using a distributed feedback diode laser as tunable light source. The linearity between the intensity of second harmonic signal and the concentration of methane was determined. The background content of methane in air was measured. The results show that gas sensors using tunable diode lasers provide a high sensitivity and high selectivity method for city gas pipeline leak detection.

The influence of low atmospheric pressure on carbon monoxide of n-heptane pool fires.

Qualitative theoretical analysis about air pressure influence upon the gas concentration of a fire plume was given, different scale n-heptane pool fires were conducted in a small and a standard compartment room in Lhasa and Hefei, respectively. The experimental results show that, in Lhasa, the average mass burning rates in the small room and the standard room both decrease, burning time increases at about 53% in small room and 45% in standard room more than in Hefei. Whereas for maximum changes of CO concentration, in the small room, in Lhasa, CO concentrations reach about twice bigger peak values at larger increase rates than in Hefei. While in the standard room, in Lhasa and Hefei, there are no significant changes for CO concentration, which agrees well with the theoretical analysis results.