Purpose: To determine the distribution of the corneal asphericity coefficient (Q value) and related factors in an Iranian geriatric population.
Methods: This population-based study was conducted in 2019 in Tehran, using stratified multistage random cluster sampling. The study population was ≥60 years of age. Participants underwent corneal imaging using a Pentacam HR. Mean keratometry, corneal astigmatism, central corneal thickness, anterior chamber depth and the overall anterior and posterior Q values (for 8 mm chord diameter) were recorded. Axial length measurements were performed using the IOL Master 500.
Results: 2457 eyes of 2457 individuals were analysed. The mean age was 67.3 ± 5.82 years and 1479 (60.2%) were female. The mean Q value for the anterior corneal surface was -0.35 ± 0.17 (95% CI: -0.35 to -0.34). The anterior Q value showed a statistically significant inverse relationship with axial length and mean keratometry, and a significant direct association with anterior chamber depth and corneal astigmatism. The mean posterior Q value was -0.41 ± 0.15 (95% CI: -0.42 to -0.40). The posterior Q value had a significant direct relationship with age, anterior chamber depth, mean keratometry and corneal astigmatism.
Conclusion: The corneal Q values in this geriatric Iranian population were more negative than the values reported in most previous studies. Corneal asphericity was greater affected by ocular biometry and corneal curvature than demographic factors and refractive status.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1111/opo.12831 | DOI Listing |
Bioengineering (Basel)
November 2024
Department of Electrical & Electronic Engineering, College of Engineering, Universiti Tenaga Nasional, Kajang 43000, Malaysia.
This paper provides comprehensive insights into the cornea and its diseases, with a particular focus on keratoconus. This paper explores the cornea's function in maintaining ocular health, detailing its anatomy, pathological conditions, and the latest developments in diagnostic techniques. Keratoconus is discussed extensively, covering its subtypes, etiology, clinical manifestations, and the application of the Q-value for quantification.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Ophthalmology, Faculty of Medicine, University of Debrecen, Nagyerdei blvd. 98, Debrecen, 4012, Hungary.
This prospective cohort study is aimed to investigate circadian variations in corneal parameters, focusing on sleep-deprived subjects. Sixty-four healthy individuals (age range: 21-76 years) actively participated in this study, undergoing examinations at least five times within a 24-hour timeframe. The analysis encompassed keratometric parameters of the cornea's front (F) and back (B) surfaces, refractive power in flattest and steepest axes (K1, K2), astigmatism (Astig) and its axis (Axis), aspheric coefficient (Asph), corneal pachymetry values of thinnest corneal thickness (Pachy Min) and corneal thickness in the center of the pupil (Pachy Pupil), volume relative to the 3 and 10 mm corneal diagonal (Vol D3, Vol D10) and surface variance index (ISV).
View Article and Find Full Text PDFPurpose: To present a new approach to customized treatments that inherently saves tissue by design, especially for pathological corneas.
Methods: From the elevation of the anterior cornea and the refractive error of the eye, the target cornea can be calculated and the difference between actual and target cornea corresponds to the tissue to be removed. In this approach, it is further possible to preset the ablation depth at one (Model 1) or two (Models 2 and 3) particular locations.
Clin Ophthalmol
November 2024
Augenzentrum Erding, Erding, Germany.
Purpose: This study aimed to evaluate one-year clinical outcomes in cataract patients with pre-existing corneal astigmatism implanted with a biconvex aspheric toric monofocal intraocular lens (IOL) with a double C-loop haptic-design.
Methods: One hundred and eighteen patients (236 eyes) with corneal astigmatism (≥0.75D) were implanted bilaterally with the PODEYE toric IOL and assessed up to 1-year after surgery.
Photodiagnosis Photodyn Ther
December 2024
Department of Ophthalmology, Changde Hospital, Xiangya School of Medicine, Central South University (The first people's hospital of Changde city), Changde, PR China. Electronic address:
Purpose: To investigate the correlations of spherical equivalent (SE), axial length (AL), and AL to corneal curvature radius ratio (AL/CR) with anterior segment biometrics in candidates for myopic refractive surgery.
Methods: Anterior segment biometrics of 2,478 myopic refractive surgery candidates measured by Pentacam were collected retrospectively. The anterior segment biometrics included anterior corneal curvature (ACC), posterior corneal curvature (PCC), white-to-white corneal diameter (WTW), central corneal thickness (CCT), corneal volume at 3 mm (CV), anterior corneal astigmatism (ACA), posterior corneal astigmatism (PCA), anterior corneal eccentricity (ACE), posterior corneal eccentricity (PCE), anterior corneal asphericity (ACAP), posterior corneal asphericity (PCAP), anterior chamber depth (ACD), and anterior chamber volume (ACV).
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!