Leon Nicholas Davies

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BACKGROUND A new commercially available optical low coherence reflectometry device (Lenstar, Haag-Streit or Allegro Biograph, Wavelight) provides high-resolution non-contact measurements of ocular biometry. The study evaluates the validity and repeatability of these measurements compared with current clinical instrumentation. METHOD Measurements were(More)
PURPOSE A clinical evaluation of the Grand Seiko Auto Ref/Keratometer WAM-5500 (Japan) was performed to evaluate validity and repeatability compared with non-cycloplegic subjective refraction and Javal-Schiotz keratometry. An investigation into the dynamic recording capabilities of the instrument was also conducted. METHODS Refractive error measurements(More)
PURPOSE A clinical evaluation of the Shin-Nippon NVision-K 5001 (also branded as the Grand Seiko WR-5100K) autorefractor (Japan) was performed to examine validity and repeatability compared with subjective refraction and Javal-Schiotz keratometry. METHODS Measurements of refractive error were performed on 198 eyes of 99 subjects (aged 23.2 +/- 7.4 years)(More)
PURPOSE The prevalence of myopia is known to vary with age, ethnicity, level of education, and socioeconomic status, with a high prevalence reported in university students and in people from East Asian countries. This study determines the prevalence of ametropia in a mixed ethnicity U.K. university student population and compares associated ocular biometric(More)
PURPOSE To evaluate the reliability and repeatability of intraocular pressure (IOP) measurements using a new rebound tonometer. METHODS Intraocular pressure was measured in 42 healthy human eyes of subjects aged 18-30 years (mean +/- standard deviation [SD] 21.5 +/- 3.2 years) using the ICare Rebound and Goldmann tonometers in two separate sessions. (More)
METHODS. Fifty prepresbyopic volunteers, aged 19 to 34 years were recruited. High-resolution images were acquired of nasal and temporal ciliary muscles in the relaxed state and at stimulus vergence levels of 4 and 8 D. Objective accommodative responses and axial lengths were also recorded. Two-way, mixed-factor analyses of variance (ANOVAs) were used to(More)
We describe a non-invasive phakometric method for determining corneal axis rotation relative to the visual axis (beta) together with crystalline lens axis tilt (alpha) and decentration (d) relative to the corneal axis. This does not require corneal contact A-scan ultrasonography for the measurement of intraocular surface separations. Theoretical inherent(More)
BACKGROUND Age-related macular degeneration (ARMD) is the leading cause of visual disability in people over 60 years of age in the developed world. The success of treatment deteriorates with increased latency of diagnosis. The purpose of this study was to determine the reliability of the macular mapping test (MMT), and to investigate its potential as a(More)
PURPOSE To assess repeatability and reproducibility, to determine normative data, and to investigate the effect of age-related macular disease, compared with normals, on photostress recovery time measured using the Eger Macular Stressometer (EMS). METHOD The study population comprised 49 healthy eyes of 49 participants. Four EMS measurements were taken in(More)
PURPOSE To develop a standardized questionnaire of near visual function and satisfaction to complement visual function evaluations of presbyopic corrections. SETTING Eye Clinic, School of Life and Health Sciences, Aston University, Midland Eye Institute and Solihull Hospital, Birmingham, United Kingdom. DESIGN Questionnaire development. METHODS A(More)