Diabetes

A 45-year-old male with diabetes, a wildlife photographer by profession, presented with specific complaints of seeing all objects in the surrounding with a greenish tinge in both eyes. He underwent a comprehensive eye examination, including Farnsworth-Munsel 100 (FM 100) hue test, multifocal electroretinogram, microperimetry, spectral-domain optical coherence tomography (SDOCT), and arterial oxygen saturation. The subject was found to have a low arterial oxygen saturation (PaO2) of 86%. He was advised inhalation of 100% oxygen for 15 min, following which he reported improvement in his visual symptoms. FM 100, OCT, and microperimetry were repeated after oxygenation. He was referred to a speciality hospital to further evaluate the cause for reduced blood oxygen saturation and was further advised for the sleep study.