Abstract
We report a diagnostically challenging case of papilloedema in a morbidly obese, 25 year old male who presented to us with blurring of vision of both eyes, but more marked in the right.Fundus examination revealed severe papilloedema , with corresponding visual field and colour vision defects. He was worked up for possible life threatening causes of papilloedema like intracranial space occupying lesion but his CT scan was normal. As his hematocrit was in the polycythemic range, multiple venesections were performed in fear that the hyperviscosity picture could be a contributing factor. However there was no change in symptoms or the fundus appearance. We could not come to a diagnosis of idiopathic intracranial hypertension too because he refused lumbar puncture. A sleep study was done as he did give symptoms of mild obstructive sleep apnea but the results were that of severe disease. He was given therapeutic nocturnal oxygen by CPAP to prevent further cardiovascular and respiratory complications and interestingly enough it helped in treating the papilloedema. He was seen 2 months after commencement of continuous positive airway pressure (CPAP) with good functional and anatomical recovery.

Key words: Obese, optic disc, swelling, nocturnal rise in CSF pressure, Apnea- hypopnea index