Digital contrast sensitivity chart with varying visual acuity: Development and validation.

BACKGROUND: Contrast sensitivity (CS) evaluation is very much necessary for the diagnosis and management of eye conditions. Several disadvantages seen in the traditionally used Pelli-Robson (PR) chart persuaded us to develop a novel digital device for the evaluation of CS at various levels of visual acuity (VA) for early detection of deteriorating vision. MATERIALS AND METHODS: The new chart was constructed on the Debian software. Letters were constructed at each level of VA from 6/60 to 6/6 with a contrast of 0-2.25 logCS. The newly constructed chart was validated against the PR chart. The data were analyzed on the SPSS software version 23. The Pearson's correlation test was used to find out the correlation between the digital CS chart (DCSC) and PR charts. RESULTS: On successful construction of a DCSC with varying VA, 56 participants were examined with a mean age of 20.43 ± 1.44 years. The mean CS with PR was 1.84 ± 0.13 logCS, whereas DCSC was 2.09 ± 0.14 logCS. The correlation between the two charts was moderate having r = 0.489 with P = 0 (confidence interval 95%). CONCLUSION: A newly developed CS chart is efficient in examining the CS in clinical practice and has good repeatability; it may help in the early detection and monitoring of ocular diseases.

Screening of cryptogamic secondary metabolites as putative inhibitors of SARS-CoV-2 main protease and ribosomal binding domain of spike glycoprotein by molecular docking and molecular dynamics approaches.

The unprecedented quick spreading of newly emerged SARS-CoV-2, the virus responsible for causing COVID-19 has put the whole world in vast crisis. Several prophylactic interventions are being performed to discover the effective anti-COVID-19 agent. Thus, the present study aims to identify the cryptogamic secondary metabolites (CSMs) as potent inhibitors of two major targets of SARS-Cov2, namely 3-chymotrypsin-like protease (3CLpro) and receptor-binding domain (RBD) of spike glycoprotein (SGP), by implementing a computational approach. Molecular docking was carried out on Autodock 4.2 software with the 3CLpro (PDB ID:6LU7) and RBD of SGP (PDB ID:6W41) of the virus. Lopinavir and Arbidol were taken as positive controls to compare the efficacy of randomly selected 53 CSMs. The drug-likeness and pharmacokinetics properties of all metabolites were accessed to discern the anti-COVID 19 activity acting well at the physiological conditions. The docking results predicted that Marchantin E and Zeorin would potentially block the catalytic site of 3CLpro with the interaction energy values of -8.42 kcal/mol and -9.04 kcal/mol, respectively. In addition, Usnic acid revealed its ability to combat the interaction of RBD of SGP to angiotensin-converting enzyme-2 in docking analysis. To certify the potent metabolites for both targets of SARS-CoV-2, MD analysis was performed for 100 ns. The results confirmed that Marchantin E could inhibit SARS-CoV-2 3CLpro and RBD of SGP as well as reveals excellent pharmacokinetic properties. The present study suggests that the identified CSMs could be quickly positioned for further experimental validation to propose promising inhibitors of SARS-CoV-2.