The G.B. Bietti Foundation IRCCS in Rome is hosting the first and only research protocol in Italy for the in vivo study of retinal microscopy using Adaptive Optics Ophthalmoscopy.
What is Adaptive Optics?
Adaptive Optics (AO) is a technique that can correct the aberrations in an optical system, whether they are lower order aberrations (defocus and astigmatism) or higher order aberrations (“irregular astigmatism”).
AO were developed in astronomy to remove defocusing caused by atmospheric turbulence on images of stars and planets taken by terrestrial telescopes.
The use of AO in ophthalmology is a recent development: the first prototype of an AO ophthalmoscope was designed at the University of Rochester (USA) in 1996, and highlighted this technique’s potential to provide extremely high resolution images of the human retina in real time.
Benefits of Adaptive Optics in Ophthalmology
Optic aberrations are the main cause of loss of focus in the human eye. Because of them, human vision is imperfect, and the images in the fundus oculi are not sharp. Adaptive Optics ophthalmoscopy, thanks to its correction of ocular optic aberrations, can improve the quality of retinal images up to a lateral resolution of 2 microns (1 micron=0.001 millimetres). The resolution of this instrument makes it possible to observe individual retinal cells in vivo, as shown in Figure 1.
Figure 1 – Retinal photoreceptor layer in a young adult photographed using Adaptive Optics ophthalmoscopy
So far, the early diagnosis and treatment of retinal disorders have been hindered by the impossibility of viewing the microscopic structures of the human eye in vivo. In many cases, retinal disorders are diagnosed only after the appearance of significant and irreversible retinal damage. Current systems to view and study the retina, such as fluorescein angiography (FAG), optical coherence tomography (OCT) or ocular ultrasounds, use ocular optics as the final lenses for focusing. As we have explained above, optic aberrations greatly reduce the resolution of the retinal images that can be acquired with current eye imaging techniques. Adaptive Optics can achieve a lateral resolution of 2 mm, which makes it possible to view individual retinal cells (Figure 1).
In the near future, Adaptive Optics ophthalmoscopy may have a significant impact on the early diagnosis and treatment of many disorders of the retina and the optic nerve. The opportunity to observe individual retinal cells will make it possible to obtain pre-clinical diagnoses of macular or nerve fibre pathologies. From a strictly scientific point of view, Adaptive Optics technology will greatly improve our knowledge of the in vivo anatomy and physiology of the human retina.
The G.B. Bietti Foundation IRCCS is currently hosting the first research protocol on Adaptive Optics ophthalmoscopy in Italy, focusing on the analysis of retinal microscopy in normal adults and those suffering from macular pathologies. For more information, contact our Health Office.