RT Journal Article SR Electronic T1 Chronic optic disc swelling overlooked in a diabetic patient with a devastating outcome JF BMJ Case Reports FD BMJ Publishing Group Ltd SP bcr0620091975 DO 10.1136/bcr.06.2009.1975 VO 2010 A1 Tasanee Braithwaite A1 Gordon T Plant YR 2010 UL http://casereports.bmj.com/content/2010/bcr.06.2009.1975.abstract AB We present a case of asymmetrical but bilateral, progressive, painless visual deterioration over 5 years to no perception of light, in a 61-year-old male diabetic patient referred for a second opinion. The patient had a chronic history of bilateral diabetic maculopathy and unexplained swelling of the optic discs. He was diagnosed with optic atrophy secondary to pseudotumour cerebri (termed idiopathic intracranial hypertension when underlying causes have been excluded), which was associated with obstructive sleep apnoea. The case highlights the critical importance of identifying and investigating chronic papilloedema for reversible causes; the sometimes subtle presentation of pseudotumour cerebri; and the vital role of visual field testing and diagnostic lumbar puncture for timely diagnosis. It also reminds us that chronic bilateral optic disc swelling is not a normal feature of diabetic eye disease, and that alarm bells should sound if reduced visual acuity seems disproportionate to the degree of maculopathy.