[The value of cardiac MRI in the risk stratification in patients with hypertrophic cardiomyopathy].

Objective: To explore the value of cardiac magnetic resonance imaging (CMR) in the risk stratification of hypertrophic cardiomyopathy (HCM). Methods: HCM patients who underwent CMR examination in Fuwai Hospital between March 2012 and May 2013 were retrospectively enrolled. Baseline clinical and CMR data were collected and patient follow-up was performed using telephone contact and medical record. The primary composite endpoint was sudden cardiac death (SCD) or and equivalent event. The secondary composite endpoint was all-cause death and heart transplant. Patients were divided into SCD and non-SCD groups. Cox regression was used to explore risk factors of adverse events. Receiver operating characteristic (ROC) curve analysis was used to assess the performance and the optimal cut-off of late gadolinium enhancement percentage (LGE%) for the prediction of endpoints. Kaplan-Meier and log-rank tests were used to compare survival differences between groups. Results: A total of 442 patients were enrolled. Mean age was (48.5±12.4) years and 143(32.4%) were female. At (7.6±2.5) years of follow-up, 30 (6.8%) patients met the primary endpoint including 23 SCD and 7 SCD equivalent events, and 36 (8.1%) patients met the secondary endpoint including 33 all-cause death and 3 heart transplant. In multivariate Cox regression, syncope(HR=4.531, 95%CI 2.033-10.099, P<0.001), LGE% (HR=1.075, 95%CI 1.032-1.120, P=0.001) and left ventricular ejection fraction (LVEF) (HR=0.956, 95%CI 0.923-0.991, P=0.013) were independent risk factors for primary endpoint; Age (HR=1.032, 95%CI 1.001-1.064, P=0.046), atrial fibrillation (HR=2.977, 95%CI 1.446-6.131, P=0.003),LGE% (HR=1.075, 95%CI 1.035-1.116, P<0.001) and LVEF (HR=0.968, 95%CI 0.937-1.000, P=0.047) were independent risk factors for secondary endpoint. ROC curve showed the optimal LGE% cut-offs were 5.1% and 5.8% for the prediction of primary and secondary endpoint, respectively. Patients were further divided into LGE%=0, 0

Infection Characteristics and Physical Prevention Strategy of Panax notoginseng Round Spot Disease Caused by Mycocentrospora acerina.

Panax notoginseng round spot disease (PRSD), caused by Mycocentrospora acerina, is the main leaf disease occurring in cultured P. notoginseng. Aiming to find a safe and efficient control method for PRSD, we studied the disease characteristics of PRSD and the optimal growth conditions of M. acerina and evaluated the efficacy of rain-shelter cultivation in PRSD control. Moreover, we described M. acerina based on morphological characterization and molecular analyses (ITS, ACT, LSU, and TEF-1α). The optimum temperature for M. acerina conidial germination was found to be 14 to 22°C. Furthermore, leaf surface wetness for at least 4 h is required for conidial germination, and conidia can successfully infect P. notoginseng when the leaf wetness lasts for more than 8 h. Additionally, rainwater splashing determines the conidial transfection distance, which is less than 2 m. Finally, our study revealed that rain-shelter cultivation is an effective and simple physical prevention strategy to control PRSD, with an average efficacy of up to 100%.

[Distribution and suitable habitats of ticks in the Yangtze River Delta urban agglomeration].

OBJECTIVE: To investigate the current distribution of ticks and predict the suitable habitats of ticks in the Yangtze River Delta urban agglomeration in 2017, so as to provide insights into tick control and management of tick-borne diseases in these areas. METHODS: All publications pertaining to tick and pathogen distribution in the Yangtze River Delta urban agglomeration were retrieved, and the geographical location of tick distribution was extracted. The effects of 19 climatic factors on the distribution of ticks were examined using the jackknife method, including the mean temperature of the wettest quarter, precipitation of the coldest quarter, mean temperature of the driest quarter, maximum temperature of the warmest month, precipitation of the driest month, minimal temperature of the coldest month, annual precipitation, mean daily temperature range, precipitation seasonality, annual temperature range, temperature seasonality, annual mean temperature, mean temperature of the warmest quarter, precipitation of the wettest quarter, isothermality, mean temperature of the coldest quarter, precipitation of the wettest month, precipitation of the driest quarter and precipitation of the warmest quarter. The distribution of ticks was analyzed in 2020 using the maximum entropy (MaxEnt) model, and the potential suitable habitats of ticks were predicted in 2070 using the MaxEnt model based on climatic data. RESULTS: A total of 380 Chinese and English literatures were retrieved, and 148 tick distribution sites were extracted, with 135 sites included in the subsequent analysis. There were 7 genera (Haemaphysalis, Rhipicephalus, Ixodes, Dermacentor, Boophilus, Hyalomma and Amblyomma) and 27 species of ticks detected in the Yangtze River Delta urban agglomeration. The climatic factors affecting the distribution of ticks in the Yangtze River Delta urban agglomeration mainly included the mean temperature of the wettest quarter and the precipitation of the coldest quarter, with 26.1% and 23.6% contributions to tick distributions. The high-, medium- and low-suitable habitats of ticks were 20 337.08, 40 017.38 km2 and 74 931.43 km2 in the Yangtze River Delta urban agglomeration in 2020, respectively. The climate changes led to south expansion of the suitable habitats of ticks in the Yangtze River Delta urban agglomeration in 2070, and the total areas of suitable habitats of ticks was predicted to increase by 18 100 km2. In addition, the high-, medium- and low-suitable habitats of ticks were predicted to increase to 24 317.84, 45 283.02 km2 and 83 766.38 km2 in the Yangtze River Delta urban agglomeration in 2070, respectively. CONCLUSIONS: Multiple tick species are widespread in the Yangtze River Delta urban agglomeration, and the future climate changes may lead to expansion of tick distribution in these areas.

Reconstructing the Perceived Faces from Brain Signals without Large Number of Training Samples.

Reconstructing the perceived faces from brain signals has become a promising work recently. However, the reconstruction accuracies rely on a large number of brain signals collected for training a stable reconstruction model, which is really time consuming, and greatly limits its application. In our current study, we develop a new framework that can efficiently perform high-quality face reconstruction with only a small number of brain signals as training samples. The framework consists of three mathematical models: principle component analysis (PCA), linear regression (LR) and conditional generative adversarial network (cGAN). We conducted a functional Magnetic Resonance Imaging (fMRI) experiment in which two subjects' brain signals were collected to test the efficiency of our proposed method. Results show that we can achieve state-of-the-art reconstruction performance from brain signals with a very limited number of fMRI training samples.

Downregulation of lncRNA SNHG7 inhibits proliferation and invasion of nasopharyngeal carcinoma cells through repressing ROCK1.

Since this article has been suspected of research misconduct and the corresponding authors did not respond to our request to prove originality of data and figures, "Downregulation of lncRNA SNHG7 inhibits proliferation and invasion of nasopharyngeal carcinoma cells through repressing ROCK1, by L. Wang, T. Xu, X. Cui, M. Han, L.-H. Zhou, Z.-X. Wei, Z.-J. Xu, Y. Jiang, published in Eur Rev Med Pharmacol Sci 2019; 23 (14): 6186-6193-DOI: 10.26355/eurrev_201907_18432-PMID: 31364118" has been withdrawn. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/18432.

The antiviral mechanisms, effects, safety and adverse effects of chloroquine.

Chloroquine, a 4-aminoquinoline derivative, was initially used to treat malaria. It was later found to have immunomodulating, anti-infective, anti-thrombotic, anti-tumor, and metabolic effects. Recently, many studies have focused on the application of chloroquine in viral infections. Most in vitro studies suggested that chloroquine exerted some benefit in infections from viruses. However, animal experiment and clinical trials that attempted to use chloroquine in prevention or treatment of viral infections have reported disappointing results. It might be attributable to inadequate steady-state whole blood chloroquine concentration necessary for exerting its antiviral effects. A 16 µM/L steady-state whole blood concentration of chloroquine should suffice in antiviral treatment with minimal toxicity. Furthermore, chloroquine has both acute and cumulative toxicity. Hence, not only the appropriate treatment dose is crucial, the occurrence of adverse reactions should also be closely monitored and treated in time. Herein, we report the antiviral mechanisms, effects, safety and adverse effects of chloroquine.

Effects of soybean isoflavones on the growth performance, intestinal morphology and antioxidative properties in pigs.

Soybean meal is rich in soybean isoflavones, which exhibit antioxidant, anti-inflammatory, antiviral and anticancer functions in humans and animals. This study was conducted to investigate the effects of soybean isoflavones on the growth performance, intestinal morphology and antioxidative properties in pigs. A total of 72 weaned piglets (7.45 ± 0.13 kg; 36 males and 36 females) were allocated into three treatments and fed corn-soybean meal (C-SBM), corn-soy protein concentrate (C-SPC) or C-SPC supplemented with equal levels of the isoflavones found in the C-SBM diet (C-SPC + ISF) for a 72-day trial. Each treatment had six replicates and four piglets per replicate, half male and half female. On day 42, one male pig from each replicate was selected and euthanized to collect intestinal samples. The results showed that compared to pigs fed the C-SPC diet, pigs fed the C-SBM and C-SPC + ISF diets had higher BW on day 72 (P < 0.05); pigs fed the C-SBM diet had significantly higher average daily gain (ADG) during days 14 to 28 (P < 0.05), with C-SPC + ISF being intermediate; pigs fed the C-SBM diet tended to have higher ADG during days 42 to 72 (P = 0.063), while pigs fed the C-SPC + ISF diet had significantly higher ADG during days 42 to 72 (P < 0.05). Moreover, compared to pigs fed the C-SPC diet, pigs fed the C-SBM diet tended to have greater villus height (P = 0.092), while pigs fed the C-SPC + ISF diet had significantly greater villus height (P < 0.05); pigs fed the C-SBM and C-SPC + ISF diets had significantly increased villus height-to-crypt depth ratio (P < 0.05). Compared with the C-SPC diet, dietary C-SPC + ISF tended to increase plasma superoxide dismutase activity on days 28 (P = 0.085) and 42 (P = 0.075) and reduce plasma malondialdehyde (MDA) content on day 42 (P = 0.089), as well as significantly decreased jejunal mucosa MDA content on day 42 (P < 0.05). However, no significant difference in the expression of tight junction genes among the three groups was found (P > 0.05). In conclusion, our results suggest that a long-term exposure to soybean isoflavones enhances the growth performance, protects the intestinal morphology and improves the antioxidative properties in pigs.

Hybridization Dynamics in CeCoIn_{5} Revealed by Ultrafast Optical Spectroscopy.

We investigate the quasiparticle dynamics in the prototypical heavy fermion CeCoIn_{5} using ultrafast optical pump-probe spectroscopy. Our results indicate that this material system undergoes hybridization fluctuations before the establishment of heavy electron coherence, as the temperature decreases from ∼120 K (T^{†}) to ∼55 K (T^{*}). We reveal that the anomalous coherent phonon softening and damping reduction below T^{*} are directly associated with the emergence of collective hybridization. We also discover a distinct collective mode with an energy of ∼8 meV, which may be experimental evidence of the predicted unconventional density wave. Our findings provide important information for understanding the hybridization dynamics in heavy fermion systems.

Downregulation of lncRNA SNHG7 inhibits proliferation and invasion of nasopharyngeal carcinoma cells through repressing ROCK1.

OBJECTIVE: Recent studies have revealed the important role of long noncoding RNAs (lncRNAs) in the progression of tumorigenesis. This study aimed to identify the biological function of lncRNA small nucleolar RNA host gene 7 (SNHG7) in the progression of nasopharyngeal carcinoma (NPC). PATIENTS AND METHODS: LncRNA SNHG7 expressions in NPC cell lines and 50 paired NPC tissue samples were detected by Real-time quantitative polymerase chain reaction (RT-qPCR). Transwell assay, wound healing assay and proliferation assay were conducted to evaluate the in vitro function of SNHG7 in NPC cells. Xenograft model was established for determining the in vivo effect of SNHG7 on tumor formation and metastasis of NPC. The underlying mechanism of SNHG7 in mediating the progression of NPC was explored by RT-qPCR and Western blot. RESULTS: SNHG7 expression was remarkably downregulated in NPC tissues compared with that in adjacent normal samples. Knockdown of SNHG7 attenuated proliferation, invasion and migration of NPC cells. Moreover, tumor size and the number of metastatic nodules were reduced in mice administrated with NPC cells transfected with sh-SNHG7. Knockdown of SNHG7 downregulated ROCK1 at mRNA and protein level. Besides, the expression of ROCK1 in tumor tissues was positively correlated to SNHG7 expression. CONCLUSIONS: Knockdown of SNHG7 inhibits migration, invasion and proliferation of NPC cells through downregulating ROCK1, which may offer a new therapeutic intervention for NPC patients.

LncRNA FAS-AS1 promotes the degradation of extracellular matrix of cartilage in osteoarthritis.

OBJECTIVE: To investigate the expression of long non-coding RNA (lncRNA) FAS-AS1 in osteoarthritis cartilage and to explore its effect on articular cartilage cells. PATIENTS AND METHODS: A total of 20 tissue samples of primary knee joint osteoarthritis and 20 tissue samples of knee joint cartilage after traumatic amputation were collected. Fluorescence quantitative polymerase chain reaction (PCR) was performed to detect the expression of FAS-AS1, MMP1, MMP13, and COL2A1 in cartilage. FAS-AS1 small interfering RNA (siRNA) was transfected to chondrocytes transiently to observe its effects on proliferation, apoptosis of chondrocytes, and the expressions of MMP1, MMP13, and COL2A1. RESULTS: The expressions of FAS-AS1, MMP1, and MMP13 in osteoarthritis tissues increased significantly, while COL2A1 presented a low expression. Reducing the expression of FAS-AS1 inhibited cell apoptosis and promote cell proliferation. Additionally, in vitro experiments showed that low expression of FAS-AS1 decreased the expressions of MMP1 and MMP13, but increased the expression of COL2A1. CONCLUSIONS: The expression of FAS-AS1 was increased in osteoarthritis, and FAS-AS1 could be involved in the development of the disease by regulating the proliferation, apoptosis of chondrocytes and promoting the degradation of extracellular matrix.

MicroRNA-520d-3p inhibits osteosarcoma progression by degradation of Akt1.

OBJECTIVE: To detect the expression of microRNA-520d-3p in osteosarcoma tissue and the function on the osteosarcoma cells proliferation. PATIENTS AND METHODS: We used qRT-PCR to access microRNA-520d-3p level from 10 cases of osteosarcoma and its adjacent tissues. The osteosarcoma cell lines were screened. The microRNA-520d-3p mimics or inhibitor was transfected into human osteosarcoma cells by liposome method, and the cell proliferation of each group was detected by the CCK8 assay. We used bioinformatics methods to detect and predict the target genes of microRNA-520d-3p. Luciferase reporter assay was utilized to detect the relative luciferase activity between microRNA-520d-3p and Akt1. Meanwhile, after cells were transfected with microRNA-520d-3p mimics, microRNA-520d-3p mimics + OE-Akt1, microRNA-520d-3p inhibitor or microRNA-520d-3p inhibitor + si-Akt1, we detected cell viability using CCK-8 assay, respectively to access the interaction between Akt1 and microRNA-520d-3p. RESULTS: Lowly expressed microRNA-520d-3p in osteosarcoma tissues was observed in comparison with adjacent tissues. After transfecting with microRNA-520d-3p mimics, the viability of MG63 and U-20S cells decreased, which was higher in cells transfecting microRNA-520d-3p inhibitor. Bioinformatics prediction and dual luciferase reporter assay illustrated that microRNA-520d-3p targeted on Akt1. At the same time, Akt1 expression was higher in osteosarcoma tissues than in adjacent ones, cell proliferation was inhibited after blocking its expression. In addition, after transfected with microRNA-520d-3p mimic, viability of MG63 and U-20S cells decreased, which can be reversed by OE-Akt1. In contrast, the viability of MG63 and U-20S cells increased after transfection with microRNA-520d-3p inhibitor and which were reversed by si-Akt1. CONCLUSIONS: Lowly expressed microRNA-520d-3p was observed in osteosarcoma; overexpression of microRNA-520d-3p can target Akt1 thus inhibiting proliferation of osteosarcoma cells.

Efficacy of computed tomography-guided implantation of 125I seeds in the treatment of refractory malignant tumors accompanied with cancer pain and its influence on tumor markers in the serum.

OBJECTIVE: This study intended to explore the efficacy of computed tomography (CT)-guided implantation of iodine-125 (125I) seeds in the treatment of refractory malignant tumors with cancer pain and its influence on tumor markers in the serum. PATIENTS AND METHODS: 76 patients with refractory malignant tumors accompanied by cancer pain that received treatments in LongHua Hospital Shanghai University of Traditional Chinese Medicine from September 2013 to August 2014 were selected. They were divided into control group and observation group using a random number table (38 patients in each group). Patients in the control group received simple chemotherapy, while those in the observation group undergone CT-guided implantation of 125I seeds in combination with chemotherapy. Recent efficacy and 1-3-year survival rate were compared between the two groups of patients. The degree of pain relief after treatment was also compared between the two groups of patients. Electrochemiluminescence method was used to detect the concentrations of carcinoembryonic antigen (CEA), sugar chain antigen 199 (CA 199), sugar chain antigen 125 (CA 125), neuron-specific enolase (NSE) and cytokeratin-19-fragment (CYFRA21-1) in the two groups of patients before treatment, and 3 days, 7 days and 30 days after treatment. RESULTS: Recent disease control rate of the patients in the observation group was higher than that of the patients in the control group (p<0.05). The 1-3-year survival rate after surgery in the observation group was significantly higher than that in the control group (p<0.05). The total efficiency of pain control in the observation group was significantly higher than that in the control group (p<0.05). The levels of tumor markers in the two groups of patients were significantly decreased after treatment, while the reduction in the observation group was more evident than that in the control group (p<0.05). CONCLUSIONS: Our results showed that CT-guided implantation of 125I seeds is effective for the treatment of patients with refractory malignant tumors accompanied by cancer pain. It can reduce the levels of tumor markers, improve the survival rate and prolong the survival time of the patients.

Association between H19 polymorphisms and osteosarcoma risk.

OBJECTIVE: The long non-coding RNA (lncRNA) H19, a maternally expressed imprinted gene, has involvement in cancer susceptibility and disease progression. However, the association between H19 polymorphisms and osteosarcoma susceptibility has remained elusive. We designed this case-control study to explore the association between H19 polymorphism and osteosarcoma risk. PATIENTS AND METHODS: In this study, we genotyped 4 tagger SNPs of the H19 gene in a case-control study including 193 osteosarcoma cases and 393 cancer-free controls. RESULTS: For the main effect analysis, rs217727 (G>A) was associated with osteosarcoma risk (GA/GG: adjusted OR = 1.51, 95% CI: 1.06-2.17, p = 0.024; AA/GG: adjusted OR = 1.89, 95% CI: 1.23-2.91, p = 0.004; additive model: adjusted OR = 1.35, 95% CI: 1.01-1.80, p = 0.043). CONCLUSIONS: This finding indicates that rs217727 polymorphism may play a role in genetic susceptibility to the risk of osteosarcoma, which may improve our understanding of the potential contribution of H19 SNPs to cancer pathogenesis.

Cloning and functional characterization of the HbSYR1 gene encoding a syntaxin-related protein in Tibetan hulless barley (Hordeum vulgare L. var. nudum HK. f.).

Tibetan barley is a staple food for the natives of Qinghai-Tibet Plateau. Drought causes a reduction in barley production. In this study, the full-length cDNA of a gene encoding a syntaxin-associated protein was cloned from the leaves of a drought-resistant variety of barley, "Himalaya 10"; its expression was evaluated during drought stress and rehydration via real-time PCR. The cloned HbSYR1 cDNA sequence was 1300 bp in length, and included an 840-bp open reading frame that encoded 279 amino acids. Sequence analysis predicted the molecular weight of the encoded protein to be 42.08 kDa, with an isoelectric point of 4.98. ScanProsite analysis showed that the HbSYR1 protein contained a SNARE family characteristic motif, five casein kinase II phosphorylation sites, two N-glycosylation sites, four protein kinase C phosphorylation sites, and two N-myristoylation sites. The TMHMM prediction program indicated that the protein does not contain a transmembrane transfer ribbon. According to the SignalP 3.0 server, this protein does not contain a signal peptide, and is not a secretory protein. Instead, this protein was suggested to be localized in the cytoplasm, as predicted by the protein subcellular localization prediction tool (PSORT). Our results indicated that HbSYR was induced by drought stress and rehydration, and was determined to be a key gene for drought resistance and water retention in barley.

NJ cluster analysis of the SnRK2, PYR/PYL/RCAR, and ABF genes in Tibetan hulless barley.

The abscisic acid (ABA) signaling pathway is known as one of the most important signaling pathways in plants and is mediated by multiple regulators. The genes SnRK2, PYR/PYL/RCAR, and ABF are relevant to both ABA-dependent and -independent signaling pathways. To elucidate the profile of these genes from Tibetan hulless barley (Hordeum vulgare L. var. nudum Hook. f.), we collected available sequences from RNA-Seq data, together with NCBI data from five other model plant species (Arabidopsis thaliana, Brachypodium distachyon, Oryza sativa, Populus trichocarpa, and Sorghum bicolor). Gene trees of SnRK2, PYR/PYL/RCAR, and ABF were constructed using a neighbor joining (NJ) method. For all genes, we identified a dominant group in which all six species were represented. Three, four, and five groups were found in the NJ trees of SnRK2, PYR/PYL/RCAR, and ABF, respectively. For each gene, Tibetan hulless barley was divided into three groups. Our analyses indicated that Tibetan hulless barley was associated with B. distachyon. The NJ cluster analysis also suggested that Tibetan hulless barley was affiliated with S. bicolor (SnRK2), A. thaliana (PYR/PYL/RCAR), and O. sativa (ABF). These results illustrate a diverse expression of genes SnRK2, PYR/PYL/RCAR, and ABF, and suggest a relationship among the six species studied. Collectively, our characterization of the three components of the ABA signaling pathway may contribute to improve stress tolerance in Tibetan hulless barley.

Efficacy of intra-arterial neoadjuvant chemotherapy through the superior epigastric artery in the treatment of locally advanced triple negative breast cancer.

Triple negative breast cancer (TNBC) is associated with aggressive behaviour and poor prognosis, but has limited treatment options. To explore novel and effective therapies against TNBC, we retrospectively analyzed the efficacy of neoadjuvant intra-arterial chemotherapy through the superior epigastric artery in the treatment of locally advanced TNBC. Fifty-one locally advanced TNBC patients who received this neoadjuvant therapy from Mar 2001 to Mar 2012 were included in this study. The superior epigastric artery was selected for cannulation to deliver chemotherapy drugs. The regimen for intra-arterial chemoinfusion consisted of 75 mg/m2 epirubicin and 75 mg/m2 docetaxel. Clinical and pathological tumor responses, disease free survival (DFS), overall survival (OS), and toxicity profiles were recorded and retrospectively analyzed. In 51 patients treated with neoadjuvant intra-arterial chemoinfusion through the superior epigastric artery, the overall response rate (ORR) was 84.3%; 16 patients achieved pathological complete response (pCR). Following surgical treatment and adjuvant chemotherapy, 5-year DFS and OS were 72.4% and 75.9%, respectively, in the study population. In addition, this neoadjuvant approach showed favorable toxicity profiles. Moreover, patients who achieved pCR showed a superior survival outcome compared with those who did not. Cox regression analysis indicated that Ki-67 expression is an independent predictor for DFS and OS. Our results suggest that intra-arterial chemotherapy through the superior epigastric artery has great therapeutic potential for the treatment of locally advanced TNBC. This approach merits further clinical evaluation and may become a novel therapeutic option for locally advanced TNBC.

[A 5 year surveillance of blindness in Yilong Commune, Yian County, Heilongjiang Province].

A sample of 35,404 people in Yilong Commune, Yian County, Heilongjiang Province, has been under surveillance since 1985 when the primary eye care system was established. In 1985, there were 52 blind people, representing a blindness prevalence of 0.15%; in 1990, the figure was reduced to 44, representing a prevalence of 0.12%. During the 5 years in between, the original 52 blind people were reduced by 15, while, from 22 cases of blinding eye diseases, 14 new cases of blindness arose, of whom 7 cases were cured. The incidence of blindness was 0.09/1000. The new cases of blindness were mainly elderly people and children, and the blinding diseases were glaucoma, cataract and congenital/hereditary diseases.

[The methodology and focus in blindness prevention from an epidemiologic point of view].

The present main causes of blindness in China are senile cataract, primary glaucoma' trachoma and corneal infections, and 80% of the blind are over 50 years of age, 75% become blind before 10 or after 50 years of age, and among 40% of the blind, the interval between visual loss in both eyes was over 1 year. The authors are of the opinion that the focus of efforts for blindness prevention should be directed to patients over 50 years of age, and particularly those of unilateral blindness, so as to prevent them from becoming bilaterally blind.