Retinal imaging with photoreceptor resolution

Retinal imaging capable of resolving individual photoreceptors cannot be obtained with conventional ophthalmoscopy but requires compensation of the individual optical aberrations that blur the optical image from the fundus. This optical compensation is normally accomplished by adaptive optics. We built a retinal imaging system based on adaptive optics can image individual cone photoreceptors. The system uses infrared radiation from a superluminescent diode (SLD) and a Hartman-Shack wavefront sensor to measure eye aberrations. An ophthalmoscope channel with a digital camera is integrated with the system to visualize the retina. A deformable mirror is used to partially compensate the aberrations of the light from the eye thereby improving the image quality and optical resolution. Images from the fundus were obtained from one healthy retina at about 0.5-1.0 deg eccentricity. The cone photoreceptor mosaic is visible and individual photoreceptors can be inspected.