Tip of the Month
Publishing date: September 2007
Tip Editors: Ann Hoste, John Salmon and John Thygesen
Tip reviewer: Roger Hitchings
The Science behind the Tip
There has been a widely held belief that diabetes increases the risk of developing primary open-angle glaucoma (POAG). However, an important selection bias in early studies may have accounted for the perceived association of these conditions. Diabetics are more likely to have been examined by an ophthalmologist, thus increasing the likelihood that their glaucoma would be detected(1).
The large Baltimore Eye Survey, a population-based study of 5.308 subjects, was unable to show a higher prevalence of POAG among diabetics1. The Ocular Hypertension Treatment Study (OHTS) of 1.636 ocular hypertensive (OH) subjects originally even found that diabetes is protective against the development of POAG(2). This counterintuitive finding is however now considered unreliable(3) as the study did not verify the self-report of diabetes and it excluded patients with diabetic retinopathy. A study of a smaller group of high-risk OH subjects with a longer follow-up could not identify diabetes as a risk factor for developing POAG either(4). And the recent Rotterdam Study is also in line with this(5).
Overall, modern investigations found no detectable effect of diabetes on risk of developing POAG.
Contributor: Ann Hoste, Antwerp
Co-editors: John Thygesen and Ann Hoste
Peer reviewers: Roger Hitchings and Anders Heijl
1. Tielsch JM, Katz J, Quigley HA, et al. Diabetes, intraocular pressure and primary open-angle glaucoma in the Baltimore Eye Survey. Ophthalmology. 1995;102:48-53.
2. Gordon MO, Beiser JA, Brandt JD, et al. The ocular hypertension treatment study: baseline factors that predict the onset of primary open-angle glaucoma. Arch Ophthalmol. 2002;120:714-20.
3. OHTS and EGPS Study Group. Validated prediction model for the development of primary open-angle glaucoma in individuals with ocular hypertension. Ophthalmology. 2007;114:10-19.
4. Bengtsson B, Heijl A. A long-term prospective study of risk factors for glaucomatous visual field loss in patients with ocular hypertension. J Glaucoma. 2005;14:135-8.
5. de Voogd S, Ikram MK, Wolfs RC, et al. Is diabetes mellitus a risk factor for open-angle glaucoma? The Rotterdam Study. Ophthalmology. 2006;113:1827-31.