A retrospective evaluation of the clinical monitoring period prior to referral for glaucoma surgery with the emphasis on visual field test results.

Purpose: To survey the monitoring of patients who underwent glaucoma surgery with the purpose of identifying routines possibly delaying the referral process.

Methods: We conducted an observational retrospective study of the 2-year period prior to referral of a cohort of patients who underwent trabeculectomy or Xen® Gel Stent implantation at Skåne University Hospital (SUS), Sweden. Data were retrieved from medical records; variables of particular interest were related to intraocular pressure (IOP) measurements and visual field (VF) tests.

Long-term development of lens fluorescence in a twin cohort: Heritability and effects of age and lifestyle.

The blue-green autofluorescence of the ocular lens increases with age, glycemia and smoking, as the irreplaceable structural proteins of the lens slowly accumulate damage from the encounter with reactive molecular species. We have conducted a prospective study of lens autofluorescence over two decades in a twin cohort. The study included 131 phakic, non-diabetic adult twins (median age at follow-up 58 years, range 41-66 years) who were examined twice at an interval of 21 years.

Heritability of Retinal Vascular Fractals: A Twin Study.

Purpose: To determine the genetic contribution to the pattern of retinal vascular branching expressed by its fractal dimension.

Methods: This was a cross-sectional study of 50 monozygotic and 49 dizygotic, same-sex twin pairs aged 20 to 46 years. In 50°, disc-centered fundus photographs, the retinal vascular fractal dimension was measured using the box-counting method and compared within monozygotic and dizygotic twin pairs using Pearson correlation coefficients.

Heritability of optic disc diameters: a twin study.

Purpose: To assess the relative influence of genetic and environmental factors on optic disc size and cup/disc ratio in healthy eyes.

Methods: A sample of 55 monozygotic and 50 dizygotic healthy twin pairs aged 20-46, all having the same sex within pairs (47 pairs were male) had optic discs measured from colour fundus photographs according to the Wisconsin Protocol. Structural equation modelling was used to estimate the relative contribution of genetic and environmental factors to the phenotype.

Machine learning classifiers for glaucoma diagnosis based on classification of retinal nerve fibre layer thickness parameters measured by Stratus OCT.

Purpose: To compare the performance of two machine learning classifiers (MLCs), artificial neural networks (ANNs) and support vector machines (SVMs), with input based on retinal nerve fibre layer thickness (RNFLT) measurements by optical coherence tomography (OCT), on the diagnosis of glaucoma, and to assess the effects of different input parameters.

Methods: We analysed Stratus OCT data from 90 healthy persons and 62 glaucoma patients. Performance of MLCs was compared using conventional OCT RNFLT parameters plus novel parameters such as minimum RNFLT values, 10th and 90th percentiles of measured RNFLT, and transformations of A-scan measurements.

Glaucomatous retinal nerve fibre layer defects may be identified in Stratus OCT images classified as normal.

Purpose: We aimed to compare the retinal nerve fibre layer (RNFL) in different Stratus optical coherence tomography (OCT) images in glaucoma eyes with RNFL thickness values within normal limits.

Methods: We studied the Stratus OCT high-resolution standard protocol for assessment of peripapillary RNFL thickness. The four glaucoma eyes presented (with reproducible visual field defects, mean deviations from -3.

Glaucoma detection by Stratus OCT.

Purpose: To investigate the diagnostic accuracy of retinal nerve fiber layer thickness (RNFLT) summary report parameters from Stratus optical coherence tomography (OCT) in glaucoma patients.

Patients And Methods: We obtained Stratus OCT measurements of peripapillary circle scans (average values) of the regular image resolution "FAST RNFLT" protocol, and of 1 circle scan of the high resolution "RNFLT" protocol in one eye of each of 62 glaucoma patients with mild or moderate visual field (VF) loss and 90 healthy subjects. Sensitivity, specificity, and diagnostic accuracy [(true positive+true negative)/all] were evaluated for all summary report parameters including the newer (eg, "Imax," the maximum thickness point in the inferior quadrant) at the normative limits of the Stratus OCT.

Glaucoma detection using different Stratus optical coherence tomography protocols.

Purpose: To examine and compare the diagnostic accuracy of retinal nerve fibre layer (RNFL) thickness measurements using different Stratus optical coherence tomography (OCT) scanning protocols.

Methods: Stratus OCT data for 90 healthy subjects and 62 glaucoma patients with mild or moderate visual field loss were prospectively collected and analysed using four RNFL thickness protocols that differed in terms of image resolution and number of scans. Cut-off levels corrected for age and refractive error were defined by reference values derived from an independent normal database.

Heredity of small hard drusen in twins aged 20-46 years.

Purpose: To examine the prevalence and heredity of small hard drusen in 220 healthy twins aged 20-46 years.

Methods: Grayscale digital fundus photography, four-field 50 degrees nonstereoscopic, in red-free illumination was performed in 58 pairs of monozygotic (MZ) twins and 52 pairs of dizygotic (DZ) twins as part of a detailed biometric characterization. Small hard drusen (diameters, <63 microm) were counted and graded by distribution type.

Heritability of retinal vessel diameters and blood pressure: a twin study.

Purpose: To assess the relative influence of genetic and environmental effects on retinal vessel diameters and blood pressure in healthy adults, as well as the possible genetic connection between these two characteristics.

Methods: In 55 monozygotic and 50 dizygotic same-sex healthy twin pairs, aged 20 to 46 years, interpolated diameter estimates for the central retinal artery (CRAE), the central retinal vein (CRVE), and the artery-to-vein diameter ratio (AVR) were assessed by analysis of digital gray-scale fundus photographs of right eyes.

Results: The heritability was 70% (95% CI: 54%-80%) for CRAE, 83% (95% CI: 73%-89%) for CRVE, and 61% (95% CI: 44%-73%) for mean arterial blood pressure (MABP).

Modelling the normal retinal nerve fibre layer thickness as measured by Stratus optical coherence tomography.

Background: The variation in retinal nerve fibre layer thickness (RNFLT) as measured by Stratus optical coherence tomography (OCT) in healthy subjects may be reduced when the effect on RNFLT measurements of factors other than disease is corrected for, and this may improve the diagnostic accuracy in glaucoma. With this perspective we evaluated the isolated and combined effects of factors potentially affecting the Stratus OCT RNFLT measurements in healthy subjects.

Methods: We included 178 healthy eyes of 178 subjects between 20 and 80 years of age.

Heritability of cilioretinal arteries: a twin study.

Purpose: To determine whether the presence of one or more cilioretinal arteries, a distinct element of the pattern of fundus vessels, is genetically programmed, influenced by environmental factors, or the result of random mechanisms of vascular development.

Methods: The fundi of 112 pairs of healthy monozygotic and dizygotic twins were examined using digital fundus photography and visual assessment of grayscale fundus photographs and color transparencies to detect the presence of cilioretinal arteries.

Results: Cilioretinal arteries were present in 45.

The nerve fibre layer symmetry test: computerized evaluation of human retinal nerve fibre layer thickness as measured by optical coherence tomography.

Purpose: To present and test a new interpretative concept, the nerve fibre layer symmetry test (NST), for computerized evaluation of retinal nerve fibre layer thickness (RNFLT) as measured by optical coherence tomography (OCT) in glaucoma.

Methods: The NST concept was constructed and tested in a pilot study. A total of 32 healthy and 40 age-matched glaucomatous eyes were included and examined by OCT, computerized perimetry, RNFL/disc photography, tonometry and a general ophthalmologic examination.

Visual acuity and refractive errors in a suburban Danish population: Inter99 Eye Study.

Purpose: The present study was performed as part of an epidemiological study, the Inter99 Eye Study. The aim of the study was to describe refractive errors and visual acuity (VA) in a suburban Danish population.

Methods: The Inter99 Eye Study comprised 970 subjects aged 30-60 years and included a random control group as well as groups at high risk for ischaemic heart disease and diabetes mellitus.

Corneal fluorescence in relation to genetic and environmental factors: a twin study.

Purpose: Corneal fluorescence is believed to be caused by advanced glycation end products formed by non-enzymatic glycation on corneal proteins. The purpose of the present twin study was to examine whether the process is related to genetic or environmental factors.

Methods: Corneal fluorescence was measured in 59 monozygotic and 54 dizygotic twin pairs.

Evaluation of heredity as a determinant of retinal nerve fiber layer thickness as measured by optical coherence tomography.

Purpose: To study to what extent genetic factors determine the retinal nerve fiber layer thickness (RNFLT) in healthy subjects.

Methods: In vivo peripapillary optical coherence tomography (OCT), clinical examination, lens fluorescence, and fundus photography were performed on both eyes of 25 monozygotic and 25 dizygotic same-sex pairs of twins. The cross-sectional study included twins aged from 20 to 45 years recruited from a population-based register.

[Optical coherence tomography].

Optical coherence tomography (OCT) is a novel technique for two and three-dimensional imaging of tissues at a histological level. The technique is based on optical technology and commercially available fiber-optic components that may be adapted for use in conventional endoscopes or intravascular catheters. OCT is a non-invasive technique, which does not utilize ionizing radiation, and it may within a few seconds provide in vivo images ("optical biopsies") of tissues in cases where excisional biopsy is hazardous or impossible, or when repeated examinations are required.