Enhancing the optical properties of [P(MMA-co-AN)/ZrO2]TF by doping fluorescein dye, TD-DFT/DMOl3 simulations and COVID-19 main protease docking

Poly methyl methacrylate-co-acrylonitrile [P(MMA-co-AN)]HB hybrid blend was first synthesized by precipitation polymerization and characterized by static light scattering. With a thickness of 200 ± 5 nm, the hybrid nanocomposite of [P(MMA-co-AN)/ZrO2]HNC thin films were fabricated by spin coating method. X-Ray diffraction studies showed a monoclinic cell structure with an average crystalline size of 180 nm for the fabricated films. An improvement in the optical properties were figured out when fluorescein dye was doped in the hybrid nanocomposite. Where the optical energy gap was decreased from 4.31 to 4.025 eV for fluorescein doped hybrid nanocomposite. While a possible energy transfer between ZrO2 and fluorescein was investigated in the laser photoluminescence spectra. DFT-CASTEP simulations were deployed to calculate the theoretical optical properties for the molecules under consideration. The structural and optical simulations of [P(MMA-co-AN)/ZrO2]HNC were found to match the experimental data. Molecular docking studies of [P(MMA-co-AN)/ZrO2]Iso against the main protease of novel corona virus COVID 19 (PDB code 6LU7 Hormone) showed an interesting interaction.

Sodium fluorescein dye as an adjunct in vitrectomy for rhegmatogenous retinal detachment in oculocutaneous albinism

A 48-year-old male with oculocutaneous albinism (OCA) presented with bilateral diminution of vision. Ocular examination revealed bilateral central corneal thinning, scarring with ectasia, depigmented irides, transillumination defects, and pseudophakia. Examination of the right eye also revealed a hyperoleon, emulsified silicon oil in the vitreous cavity, and an attached retina, while the left eye had a total rhegmatogenous retinal detachment (RRD). This case describes a unique set of challenges (the presence of an ectatic scarred cornea and a hypopigmented fundus) and sodium fluorescein dye as an adjunct in the surgical management of a complex RRD. A review of literature highlighting the association of keratoconus and RRD in OCA is also presented in this report.

Effects of fluorescein on corneal endothelial morphology after fundus fluorescein angiography in patients with diabetic macular edema

PURPOSE

To evaluate the effects of fluorescein dye on corneal endothelial morphology (CEM) after fundus fluorescein angiography (FFA) in patients with diabetic macular edema (DME).

METHODS

In this retrospective study, patients were divided into two groups, nonproliferative diabetic retinopathy (Group-1, NPDR) and proliferative diabetic retinopathy (Group-2, PDR). CEM properties including endothelial cell density (ECD), coefficient of variation of cell area (CV), average cell area (AVG), percentage of hexagonal cells (HEX), and central corneal thickness (CCT) were measured before FFA and at week 1 and month 1 after FFA were collected from patients' charts.

RESULTS

The study consisted of 48 patient's 48 eyes in Group-1 and 50 patient's 50 eyes in Group-2. In both groups, the mean ECD, CV, AVG, HEX, and CCT measurements at week 1 and month 1 after FFA did not differ statistically from the mean measurements before FFA (p > 0.05). The mean ECD measurements in Group-1 were higher than that in Group-2 and showed statistically significant differences among the groups (p < 0.01 for all). In the Pearson correlation analysis in Group-1, there was no statistically significant relationship between best-corrected visual acuity (BCVA) and (intraocular pressure) IOP values and ECD, AVG, CV, HEX, and CCT measurements (except central macular thickness [CMT] and HEX) before FFA, at week 1 and month 1 after FFA (p > 0.05). In Group-2 there was no statistically significant relationship between BCVA, IOP, and CMT measurements and ECD, AVG, CV, HEX, and CCT measurements before FFA, at week 1 and month 1 after FFA (p > 0.05).

CONCLUSIONS

There is no significant change in CEM after FFA in patients with NPDR and PDR with DME.

Use of intra operative fluorescein dye for prediction of flap viability

BACKGROUND

A successful flap is dependent on its vascularity. During dissection, flap viability may become compromised due to inadequate perfusion from the vascular pedicle(s) on which the flap is based. Various methods have been proposed to determine viability of a flap both, intraoperatively and postoperatively. The ideal method must be simple, accurate, reproducible and safe. The purpose of this study was to study the role of fluorescein dye for prediction of flap viability.Materials &amp; Methods: Thirty patients undergoing flap coverage for various defects were evaluated. Flaps were elevated and evaluated clinically for viability. Intravenous fluorescein was injected into the patients prior to flap inset and its course through the flap was monitored under ultraviolet light. Fluorescent areas were marked intraoperatively (size and location documented). Areas of viable flaps were documented on post-operative day 5 and comparisons made.

RESULT

The area of viable flap as determined using intra operative fluorescein dye administration corresponded to surviving flap area on post-operative day 5, in 27 of the 30 cases studied, giving positive predictive value of 90%. Overall, the dye had an accuracy of 99.03% compared to intraoperative clinical flap assessment accuracy of 95.70%. Marginal necrosis was seen in 16.6 % of all cases. No allergic reaction to the dye was observed.

CONCLUSION

- Accurate assessment of flap viability is an area of constant research. Use of intraoperative fluorescein dye for prediction of flap viability has an accuracy of 99.03% compared to intraoperative clinical flap assessment accuracy of 95.70%. In a few cases, the dye is prone to underpredict the area of viable flap tissue. The dye can be used to corroborate clinical asessment of viable flap tissue when used intraoperatively. The dye was found to be safe and easy to use.

Cerebrospinal fluid rhinorrhea: endoscopic repair based on a combined diagnostic approach

BACKGROUND

The treatment of cerebrospinal fluid rhinorrhea has evolved since the first recorded instance of this condition by Willis in 1676. The advancements in radiology and endoscopic nasal surgery have provided ways to solve this potentially dangerous condition. But even now quite a few questions remain unanswered while tackling this difficult clinical situation. Laboratory tests for confirming the presence of cerebrospinal fluid in nasal fluid can yield false positive results and radiological evaluation has never been foolproof when it comes to small leaks and multiple leaks. Also the postoperative recurrence needs to be brought within acceptable limits.

OBJECTIVES

We have tried to evaluate endoscopic repair of CSF rhinorrhea based on a combined diagnostic approach. The methods for diagnosis of CSF rhinorrhea have been reevaluated based on our experience with a view to prevent recurrences and complications.

MATERIALS AND METHODS

The study group included twenty patients of CSF rhinorrhea who have been treated by endoscopic repair and spans over a period of five years from January 2001 to December 2005. A combination of retrospective and prospective methods of study has been used. Patients have been subjected to laboratory, radiological and dye studies for confirmation and localization of leak. Endoscopic repair of CSF fistula with composite graft and fibrin glue has been performed. Postoperative management included intracranial pressure reducing measures and control of primary condition in cases of spontaneous leak.

RESULTS

Endoscopic repair of CSF rhinorrhea produced a first time success rate of 92%. CT/MR Cisternogram could localize the defect in 85% cases while intrathecal fluorescein aided localization whenever it was used. The use of fibrin glue with composite graft and postoperative intracranial pressure reducing measures could improve the success rate.

CONCLUSION

Management of a suspected CSF leak requires a combined diagnostic approach. Endoscopic repair with composite graft and fibrin glue should be the first line of management in cases of CSF rhinorrhea requiring surgical closure. Intracranial pressure reducing measures play an important role in preventing postoperative recurrence.