Gene Expression Divergence is Coupled to Evolution of DNA Structure in Coding Regions

Sequence changes in coding region and regulatory region of the gene itself (cis) determine most of gene expression divergence between closely related species. But gene expression divergence between yeast species is not correlated with evolution of primary nucleotide sequence. This indicates that other factors in cis direct gene expression divergence. Here, we studied the contribution of DNA three-dimensional structural evolution as cis to gene expression divergence. We found that the evolution of DNA structure in coding regions and gene expression divergence are correlated in yeast. Similar result was also observed between Drosophila species. DNA structure is associated with the binding of chromatin remodelers and histone modifiers to DNA sequences in coding regions, which influence RNA polymerase II occupancy that controls gene expression level. We also found that genes with similar DNA structures are involved in the same biological process and function. These results reveal the previously unappreciated roles of DNA structure as cis-effects in gene expression

Bilateral Subinternal Limiting Membrane Crystalline Deposits Secondary to Terson Syndrome

Background. We report the case of bilateral, subinternal limiting membrane crystalline deposits in a patient with Terson syndrome, describe the possible pathogenesis, and highlight management. Case Presentation. A 24-year-old male with a history of traumatic massive parenchymal and subdural frontal hemorrhage presented to our clinic seven months after a motor vehicle accident, prolonged hospitalization, and rehabilitation, complaining of decreased vision in both eyes. The Snellen visual acuity was 1/60 in the right eye, and 6/60 in the left eye. Fundus examination showed an organized white vitreous hemorrhage in both eyes with almost no view of the retina. The anterior segments were normal. He underwent a 25-gauge pars plana vitrectomy in both eyes. During the surgery, golden crescent-shaped sediment consisting of small crystals was observed under the internal limiting membrane in both eyes: anterior to the inferior temporal vascular arcade in the right eye and posterior to it in the left eye. Internal limiting membrane (ILM) peeling after staining with ILM-blue dye was performed in the left eye, where the finding involved the macula. One year after the surgery, visual acuity significantly improved to 6/8.5 on the right and 6/6 on the left. Epiretinal membrane formation was observed in the right eye, where ILM peeling was not performed. Conclusion. Subinternal limiting membrane crystalline deposit finding is a rare condition. Consider performing internal limiting membrane peeling and sediment removal in cases with macular involvement. In cases where crystals are concentrated outside of the macula, follow-up may be considered

COVID-19 Pandemic Lockdowns Impact on Visual Acuity of Diabetic Macular Edema: A Large cohort

Introduction: Evaluating the impact of unplanned treatment gap, secondary to COVID-19 pandemic lockdowns, on visual acuity in previously treated diabetic macular edema (DME) patients.Methods: A multi-center, retrospective, study of DME patients, previously treated with anti-VEGF injections who were followed-up during COVID-19 pandemic (2020) comparing to pre COVID-19 period (2019) Results: A total of 634 DME patients with a mean age of 68.4 years met the inclusion criteria, 385 were assessed in 2019 (pre COVID-19) and 239 patients assessed in 2020 (COVID-19). Baseline BCVA among patients in 2019 and 2020 was 0.52 +/- 0.44, 0.45 +/- 0.43 (LogMAR, respectively). There was no significant difference between the years 2020 and 2019 in baseline BCVA (p=0.07). Mean number of anti-VEGF injections was significantly lower (5 Vs 6, p<0.01), with a major lower ratio of injections per patient in the COVID-19 first lockdown period (March-June 2020) in the COVID-19 group. Baseline BCVA (p<0.01) was the only significant predictor of final BCVA. Number of injections, age, gender and the year weren't found as a predictor of final BCVA.Conclusions: In a large cohort of DME patients, an unplanned delay in treatment with anti- VEGF injections for 2-3 months due to COVID-19 pandemic lockdown, had no significance impact on visual acuity. For most patients, returning to routine treatment regimen was sufficient for BCVA maintaining

IMPACT OF COVID-19 PANDEMIC LOCKDOWNS ON VISUAL ACUITY OF PATIENTS WITH NEOVASCULAR AMD A Large Cohort

Purpose: Evaluating the impact of delayed care, secondary to coronavirus disease 2019 (COVID-19) pandemic lockdowns, on visual acuity in previously treated neovascular age-related macular degeneration (nAMD) patients. Methods: This was a multicenter, retrospective, study of patients with nAMD previously treated with anti-VEGF injections who were followed up during 2019 (pre-COVID-19) and compared with patients with nAMD during 2020 (COVID-19). Results: A total of 1,192 patients with nAMD with a mean age of 81.5 years met the inclusion criteria. Of these, 850 patients were assessed in 2019 (pre-COVID-19) and 630 patients were assessed in 2020 (COVID-19). Three hundred eight patients were assessed through both 2019 and 2020 and thus were included in both cohorts. There was no significant difference between 2020 and 2019 in baseline and change in best-corrected visual acuity (BCVA; P = 0.342 and P = 0.911, respectively). The mean number of anti-VEGF injections was significantly lower (5.55 vs. 6.13, P < 0.01), with constant lower ratio of injections per patient in the COVID-19 period. Baseline BCVA (0.859, P < 0.01), number of injections (-0.006, P = 0.01), and age (0.003, P < 0.01) were predictors of final BCVA. Conclusion: In patients with nAMD, delayed care secondary to COVID-19 pandemic lockdowns has no statistically significant impact on BCVA. Best-corrected visual acuity, older age, and lower number of yearly anti-VEGF injections are predictors for decrease BCVA