Clues to duration of undiagnosed disease from retinopathy and maculopathy at diagnosis in type 2 diabetes: a cross-sectional study.
| Autor: | Ellis JD; Department of Ophthalmology, Ninewells Hospital and Medical School, Dundee DD1 9SY, UK. john.ellis@nhs.net, Zvandasara T, Leese G, McAlpine R, Macewen CJ, Baines PS, Crombie I, Morris AD |
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| Jazyk: | angličtina |
| Zdroj: | The British journal of ophthalmology [Br J Ophthalmol] 2011 Sep; Vol. 95 (9), pp. 1229-33. Date of Electronic Publication: 2010 Dec 22. |
| DOI: | 10.1136/bjo.2010.196204 |
| Abstrakt: | Aims: To extrapolate, from the proportion of subjects with observable retinopathy at diagnosis of type 2 diabetes mellitus in routine clinical practice, the mean duration of undiagnosed diabetes. Methods: On 1 October 1999, there were 4313 patients with type 2 diabetes in the 41 participating practices in the Tayside region (registered with one of 166 GPs). 501 (12%; 95% CI 11 to 13%) patients were selected using a pseudo-random number allocation algorithm, and practice lists checked for recently deceased, non-residents (45 exclusions). Retinopathy was graded by validated slit lamp biomicroscopy and four-field stereo photography. Date of first diagnosis of diabetes was ascertained from the regional diabetes register created using multiple source data capture. Results: Of living Tayside resident patients, 295 from 456 invited type 2 patients (65%) were examined. 14.68% (95% CI 12.48 to 16.88%) were found to have retinopathy at diagnosis. Assuming a linear model, these data suggest that the onset of detectable retinopathy occurs 5.77 years (95% CI 4.6 to 7 years) before diagnosis. Comparison using the log rank test with survival to onset of sight threatening retinopathy/maculopathy in 291 patients with type 1 diabetes mellitus also examined from the same population cohort showed the 95% CIs of length of preclinical diabetes to be between 3.0 and 9.4 years. Conclusion: There is accumulating evidence to question the assumption of linearity as a model of choice. The authors' understanding of a distinct glycaemic threshold for retinal change is also overly simplistic and consequently the bounds of uncertainty concerning the preclinical duration of disease are considerable. |
| Databáze: | MEDLINE |
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