Clinical characteristics and management outcomes of acute retinal necrosis.

This study investigates patient's clinical characteristics and management outcomes of PCR-positive Acute Retinal Necrosis (ARN). The patient's clinical characteristics of the disease, and therapeutic approaches were assessed. Data from the medical records of 40 eyes of 40 patients were analyzed. The mean ± standard deviation (SD) of the age of the patients was 47.8 ± 14.1 years (16-84 years old). The median follow-up time was 160 days, with a range of 120-370 days. The mean ± SD of patients' primary and final BCVA was 1.24 ± 0.78 and 1.08 ± 0.86 LogMAR, respectively. The final BCVA increased significantly after the treatment in the last follow-up period in patients who did not undergo PPV (p = 0.029). Although, vision changes were not statistically significant in patients who underwent PPV (p = 0.549). 75% of our patients had a positive aqueous PCR for VZV, and the second most common causative agents were CMV and HSV (10% for each). Besides, rhegmatogenous retinal detachment (RRD) occurred in 25% of our patients. Our analysis showed that the presenting visual acuity and RRD occurrence are the significant prognostic factors for final blindness in ARN.

Acute retinal necrosis. Management and visual outcomes: a case series.

BACKGROUND: The present study reports the functional and anatomical outcomes of eyes with acute retinal necrosis(ARN). METHODS: This is a retrospective case series conducted at a tertiary Eye Hospital from March 2015 to March 2020. Medical records of patients with clinical and laboratorial-Polymerase Chain Reaction (PCR)-diagnosis of ARN were reviewed. To identify factors related to the outcomes of visual acuity(VA) and retinal detachment (RD) over time, Cox proportional hazards regression modeling and survival analyses were used. RESULTS: Twenty-three eyes of 23 patients (16 male, 7 female) were reviewed. Based on the PCR results, 16 cases (69.6%) had Varicella zoster virus, 3 cases (13%) had Cytomegalovirus, 1 patient (4.3%) had Herpes simplex virus associated ARN, and 1 case (4.3%) had negative PCR. The incident rate for ≥ 2-line VA gain was 0.28/eye-year (EY) (95% CI 0.21 ± 0.26) while the rate of severe vision loss was 0.09/eye-year (95% CI 0.05 ± 0.08). The RD development was observed at a rate of 0.43/eye-year (0.42 ± 0.02), which occurred in 9 eyes with a mean time of 100 days after the initial presentation of ARN. Patients' age was the only factor associated with 2-line or more gain in VA over time with a hazard ratio of 0.921 (95% CI 0.854-0.993, P = 0.032). CONCLUSIONS: Generally, although being crucial, treatment is not highly effective in improvement of VA and decrease of RD development, as well as vision loss, in patients with ARN. However, treatment prevents fellow eye involvement efficiently. Younger age is associated with better response to treatment and more chance to achieve better VA.

Correlation of Microstructure, Rheological and Morphological Characteristics of Synthesized Polypropylene (PP) Reactor Blends Using Homogeneous Binary Metallocene Catalyst.

A novel binary homogeneous catalyst system based on (I): rac-Me2Si(2-Me-4-PhIn)2ZrCl2 and (II): (2-PhIn)2ZrCl2 catalysts at various molar ratios was utilized for the synthesis of polypropylene (PP) reactor blends with bimodal molecular weight distribution (MWD). The results of gel permeation chromatography analyses revealed that the catalyst (I) was responsible for the production of i-PP with high molecular weight (MW) while the individual use of catalyst (II) led to the production of an elastomeric PP with relatively low MW. However, application of the binary catalyst system led to high MW bimodal MWD products being highly dependent on the catalysts' molar ratios. Increasing the molar ratio of catalyst (II) to catalyst (I) resulted in a notable enhancement of the products' complex viscosity due to the increased MW, a higher level of chains' entanglements and formation of amorphous blocks along the polymer chains. All products exhibited a single relaxation that shifted towards longer times upon changing the catalysts' molar ratios. Scanning electron microscopy results revealed that the fracture surface of the blends, synthesized by the binary catalyst system, became more heterogeneous in comparison with the products obtained by the individual use of the catalyst (I). The observed heterogeneity was found to increase by increasing the amount of catalyst (II). Such morphological change was further corroborated by the dynamic rheological data, indicating a promising correlation between the linear rheological results and the morphological features of the synthesized PP reactor blends.