[Emerging technology for retinal function testing: two-photon microperimetry]

The technique of 2‑photon microperimetry is an emerging procedure that combines measurement of retinal sensitivity with retinal imaging and offers substantial improvements compared to conventional microperimetry. Conventional microperimetry relies on 1‑photon linear absorption while 2‑photon microperimetry relies on the simultaneous absorption of two photons, leading to enough energy for photoisomerization of visual pigments and perception of colors, such as green. This 2‑photon absorption process has shown a lower spread of measurements at one retinal location, leading to more reproducible data compared to conventional microperimetry. The current literature also suggests that 2‑photon microperimetry provides more reliable measurements in the presence of lens opacities, a common issue in an aging eye. Furthermore, it has been successfully utilized to assess retinal function in patients with diabetic retinopathy, age-related macular degeneration and glaucomatous neuropathy. These advantages highlight the very promising application in clinical settings. Future adjustments focusing on implementing this technology in the clinical practice could improve outcomes in the early detection and monitoring of retinal diseases.