Methods for detecting age-related maculopathy: a comparison between photographic and clinical assessment

To examine the sensitivity, specificity and overall agreement between photographic and clinical assessment in detecting age-related maculopathy (ARM) features in the context of an epidemiological study, the Vitamin E, Cataract and Age-related Maculopathy Study (VECAT).

A total of 1204 volunteers aged between 55 and 80 years of age, who were enrolled in the VECAT Study, had both slit-lamp biomicroscopy examination and fundus photos taken as part of the baseline ophthalmic examination. The Nidek 3-DX fundus camera (Nidek, Gamagori, Japan) was used to produce paired, one-framed, coloured, 15 degrees stereoslides of the macular area at a fixed angle. An International Classification and Grading System for Age-related Maculopathy and Age-related Macular Degeneration was used to grade the stereoslides. Agreement in the detection of drusen, pigment abnormalities, and late stage ARM features was assessed using unweignted kappa statistic. Cases of disagreement were verified using clinical data records, grading documentation and the review of stereoslides.

Macula status was available for 2386 eyes. For drusen of size < 63 microm, sensitivity was 47%, specificity was 68% with a kappa value of 0.20. For drusden > or = 125 microm, sensitivity and specificity were > or =81%. Kappa values ranged from 0.56 to 0.71. Levels of agreement for pigment abnormalities and late ARM were in the substantial range (i.e. kappa values from 0.70 to 1.00).

Slit-lamp biomicroscopy was found to be comparable to photograding (using the Nidek 3-DX fundus camera) for detecting features pertaining to ARM. However, given the objectivity and permanency of stereoslides, photograding is still the more reliable and the preferred system of assessing ARM in the context of an epidemiological study.