If you have a patient with well controlled diabetes, but is on multiple hypertensive meds and has cotton wool spots, give some thought to sleep apnea, especially if they are obese. It seems sleep apnea is under-diagnosed and carries quite a bit of morbidity. It is quite stressful on the vascular system in the eye, and the retina will look worse than you might expect. Send the patient to a sleep lab, or better yet, send the patient to his PCP and let him go through the hassle of completing the paperwork for that test!