The VECAT Study: Methodology and statistical power for measurement of age-related macular features

Clinical Exper Ophthalmology

Tikellis

et al. 2003

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Iris colour, ethnic origin and progression of age‐related macular degeneration

Nicolas

Clinical Exper Ophthalmology

Tikellis

et al. 2003

“…Details of the grading procedures are presented elsewhere. 26,27 Slit lamp examination Following ophthalmic photography, the clinical slit lamp eye examination was conducted. Pterygium and corneal opacities in the optical zone were recorded and graded in millimeters (pterygium) and degree of transparency (corneal opacity), as they could affect the quality of macular photography and subsequently the grading assessment.…”

Section: Ophthalmic Examinationmentioning

confidence: 99%

Methodology of the Cardiovascular Health and Age-Related Maculopathy (CHARM) Study

Ophthalmic Epidemiology

McNeil

Dimitrov

et al. 2004

Self Cite

Age-related macular degeneration (AMD) is responsible for the majority of visual impairment in the Western world. Epidemiological studies examining risk factors for AMD are needed to develop strategies for the prevention of blindness from this condition. A number of potentially modifiable risk factors for AMD have been identified; however, only smoking has been a consistent risk factor across the numerous studies. A growing body of evidence suggests that AMD and cardiovascular disease may have common risk factors. The Cardiovascular Health and Age Related Maculopathy (CHARM) Study was established to examine the risk factors for AMD and its progression, in particular risk factors associated with cardiovascular disease. Examining risk factors for prevalent AMD, cases with AMD were compared with age and gender matched controls with no AMD features. For the assessment of AMD progression, the study examined in 2001 and 2002 those participants with early AMD, or age-related maculopathy (ARM), who had undergone baseline examination between 1992 and 1995 and compared the characteristics of those who had progression of AMD with those who did not. The CHARM study involved both ophthalmic and cardiovascular examinations. Standardised clinical eye examination and grading of the macular stereo photographs were used to determine the AMD status and progression. To examine cardiovascular status, carotid artery ultrasound imaging analysis of systemic arterial compliance, augmentation index and pulse wave velocity were performed. The traditional and novel risk factors for CVD such as levels of glucose, cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, fibrinogen, C-reactive protein, immunoglobulins A and M, homocysteine, oxidized LDL and the exposure to the Chlamydia Pneumonia infection were determined. DNA was collected for apolipoprotein E genotyping. The present paper outlines the primary aims of the CHARM study, the methodology involved and the recruitment results.

“…13 Details of the grading procedures are presented elsewhere. 14,15 In brief, following the specifications outlined by the International group, a grid consisting of three circles concentric with the centre of the macula that represent, respectively, the central, middle, and outer subfields was used to assist with the grading of early and late AMD lesions. The central, middle, and outer circles have diameters of 1000, 3000, and 6000 mm, respectively.…”

Section: Assessment Of Amd On Macula Photographsmentioning

confidence: 99%

Characteristics of progression of early Age-related macular degeneration: the Cardiovascular Health and Age-related maculopathy Study

Tikellis

Dimitrov

et al. 2006

Eye

Aims To determine the risk of age-related macular degeneration (AMD) progression posed by the presence of each early AMD characteristic. Methods A prospective cohort study of 254 participants aged 50 years and older, all with early AMD features at their baseline visit followed for an average of 7 years. Stereoscopic colour fundus photographs were graded for early AMD features using the International Classification System. AMD status was stratified into six exclusive levels along a continuum of disease severity according to drusen type, pigmentary abnormalities, or late AMD. Progression was assessed according to three definitions: a change between or within a severity level, or by side by side grading. Results The progression rate of early AMD ranged between 3.4 and 4.67% per annum depending upon the definition used. In total, 15 (6%) cases progressed from early AMD to the late complication of AMD. After controlling for age and smoking, cases with soft indistinct drusen at baseline were at a greater risk of progressing from early to late AMD than were cases without this characteristic (OR ¼ 3.72, 95%CI 1.20-11.54; P ¼ 0.02). Conclusion Our proposed definitions of AMD progression give rates that are consistent with current knowledge of progression and its determinants. Each early AMD characteristic conveys its own risk of progression to an eye, with soft indistinct drusen carrying the greater risk. An international consensus on what defines AMD progression would greatly help the research community when trying to assess the importance of new risk factors and the effectiveness of novel interventions.