Baseline characteristics of participants in the natural history study of macular telangiectasia (MacTel) MacTel Project Report No. 2.

Publication Type
Journal Article
Year of Publication
Clemons, Traci E; Gillies, Marc C; Chew, Emily Y; Bird, Alan C; Peto, Tunde; Figueroa, Maria J; Harrington, Molly W; MacTel Research Group
Ophthalmic Epidemiol
Date Published
2010 Jan-Feb
Aged; Female; Fluorescein Angiography; Health Status; Humans; Male; Middle Aged; Photography; Retinal Diseases; Retinal Vessels; Risk Factors; Telangiectasis; Time Factors; Tomography, Optical Coherence; visual acuity

PURPOSE: To describe the baseline characteristics of a large international cohort of patients with macular telangiectasia type 2 (MacTel Type 2) in anticipation of a longitudinal natural history study to evaluate structural and functional changes, identify potential risk factors and related outcomes.

METHODS: Images including fundus photographs, fluorescein angiograms, optical coherence tomography and fundus autofluorescence were collected. A grading system for MacTel type 2 was developed by the central reading center to evaluate lesion characteristics. Relationships between lesion characteristics and visual acuity were evaluated.

RESULTS: A total of 310 participants have been enrolled in the study. The mean time since diagnosis was 3 years (range 0 to 25 years). The mean age at the baseline examination was 61 +/- 9 years. The mean visual acuity in the better eye was approximately 20/32 Snellen equivalents and approximately 20/50 in the worse eye. The visual acuity in the better eye of half of the participants was 20/32 or better. We found some relationships between visual acuity and lesions characteristic of MacTel Type 2.

CONCLUSIONS: This is the first large-scale study of patients with MacTel Type 2. More than half of the patients had 20/32 or better vision in their better eye, which is a sign that decreased function in these participants may not be reflected in central visual acuity. These findings highlight the limitation of using visual acuity measurements as a measure of function and as an outcome measure in potential clinical trials in patients with MacTel Type 2.