Bibliometric analysis of research relating to refractive cataract surgery over a 20-year period: from 2003 to 2022.

AIM: To investigate the research trend on refractive cataract surgery, compare the contributions of different countries, institutions, journals, and authors in the past 20y, and explore its potential research hotspots. METHODS: All publications were extracted relating to refractive cataract surgery from 2003 to 2022 from Web of Science. Document types were limited to original articles and reviews, and the language was limited to English. Quantitatively and qualitatively of the publications were analyzed through Microsoft Excel and GraphPad Prism. VOSviewer and CiteSpace were used for bibliometric and visualized analysis. RESULTS: A total of 2090 publications were enrolled. The United States contributed the most publications (434, 20.8%), followed by China (345, 16.5%) and England (163, 7.80%). Publications from the United States were cited more frequently (9552 citations) with the highest H-index of 48. China ranked second in the total number of publications, the papers were not cited that frequently (3237 citations), and the H-index ranked sixth (H-index=29). Journal of Cataract and Refractive Surgery published the most papers (333, 15.9%), and the University of London had the highest number of publications (75, 3.59%). Dick HB from Germany published the most papers. Corneal astigmatism-related research, cataract surgery method-related research, postoperative visual-quality relate to research, and postoperative complications-relate research are the hotspots in this field. The most significant limitation was that the database was updated frequently and the latest publications were not included. CONCLUSION: The bibliometric analysis shows a brief summarization of the contribution of the authors, institutions, countries, and journals. Corneal astigmatism, cataract surgery method, postoperative visual-quality and postoperative complications related researches have become the emerging hotspots, which can give a direction in the future researches.

Trends in operating room-based glaucoma procedures at a single eye center from 2016-2020.

AIM: To evaluate trends in glaucoma procedures at the Peking University Eye Center in 2016-2020. METHODS: A retrospective search of all glaucoma procedures performed at our institution were performed. Data were analyzed by calculating the absolute numbers and relative weightage of each procedure per year. RESULTS: The average age of glaucoma patients undergoing surgical procedures was 62.33±17.87y, and 55% were women. From 2016 to 2019, the number of surgical procedures performed in glaucoma patients showed an overall upward trend from 749 to 1460, although it decreased slightly in 2020 (n=1393), probably due to the COVID-19 pandemic. The number of trabeculectomies did not change significantly in 2016 (n=161) to 2018 (n=164) but decreased in 2019 (n=139) to 2020 (n=121), indicating a reduction in its relative weightage among glaucoma procedures (from 21.50% to 8.69%). The number of glaucoma drainage device implantations and minimally invasive glaucoma surgeries both increased (50 and 58 respectively in 2019), except in 2020. The number of transscleral cyclophotocoagulation procedures was relatively stable, increasing until 2017 (n=218) and then decreasing. Cataract surgeries with or without glaucoma procedures accounted for a large number of the total surgeries, increasing from 247 (32.97%) in 2016 to 967 (69.42%), among which cataract extraction combined with goniosynechialysis was the most frequent. CONCLUSION: The overall increase in the number of operating room-based surgical procedures is significant. Trabeculectomy is one of the most commonly performed procedures, despite the relative decline in its weightage. Other procedures, including use of glaucoma drainage devices and mini shunts and minimally invasive glaucoma surgeries, are gaining greater acceptance. Notably, lens-related surgery plays an important role in glaucoma management.

Discovery of NLO Semiorganic (C5H6ON)+(H2PO4)-: Dipole Moment Modulation and Superior Synergy in Solar-Blind UV Region.

We herein report a novel semiorganic NLO material, (C5H6ON)+(H2PO4)-, 4HPP, showing promising excellent properties in the important solar-blind UV region where LAP and its deuterated form DLAP are the only commercialized semiorganic materials. For the first time, the 4-hydroxypyridine (4HP+, (C5H6ON)+) cation is identified as NLO active and how to eliminate the dipole-dipole interaction to avoid the unwanted center-symmetry-trap caused by the polar-induced susceptibility is well demonstrated. Remarkably, 4HPP exhibits competitive and even better properties compared with LAP that include better thermal stability (decomposition at 166 vs 112 °C of LAP); wider transparency range (0.26-1.50 µm); very strong SHG response (3 × KDP); a suitable large birefringence (Δncal = 0.25 vs 0.075 of LAP); and a high laser-induced damage threshold (2.2 × KDP). First-principles calculations show that the π-conjugated organic (4HP)+ cation governs the optical anisotropy, whereas the synergy of the organic and inorganic moieties dominates the SHG process. Our discovery points out a new path for the rational design of high performance semiorganic materials that require an acentric structure.

How To Maximize Birefringence and Nonlinearity of π-Conjugated Cyanurates.

Materials with large birefringence (Δn) are highly needed by fiber-optic isolators, whereas crystals showing strong second-order harmonic generation (SHG) are the key component for all-solid-state laser devices. Cyanurate constructed by the planar π-conjugated ring (C3N3O3, CY) is a class of fascinating materials exhibiting not only very large Δn (larger than that of calcite) but also strong SHG (2 times that of ß-BaB2O4, BBO). Here, we report five new cyanurates (I-V) and their single-crystal structures; among them, II realizes a Δn = 0.4, the maximum in the cyanurate family, and IV realizes a d33 = 6.69 pm/V, one of the highest values in the cyanurate family. We discover a dependence between Δn and the coplanarity of the CY rings that is explicitly described by a Boltzmann function, in which the coplanarity is defined by the dihedral angle (γ) between the CY plane and the principal optical axes XY plane. II realizes the maximum Δn due to its zero γ that indicates perfect coplanarity. Such a Δn-γ dependence also allows the Δn prediction of cyanurates. Furthermore, we uncover that the SHG intensity of cyanurates increases monotonically as the angle (θ) between the maximum hyperpolarizability (ßmax) vector and the crystal 21 polar axis decreases. We predict the dij to extend well beyond such a value and to maximize at θ = 0°. Our results have significant implications for the future rational design and discovery of high-performance materials of π-conjugated and other related systems.