Green filter overlays make it easier to spot retinal cracks

New research found that the application of green filter overlay helps resident physicians to identify breaks on fundus photos when compared to traditional settings. The study results were published in the journal Graefe's Archive for Clinical and Experimental Ophthalmology. 

Ophthalmologists can now more clearly see and record retinal diseases due to advancements in retinal imaging. The first ultra-widefield (UWF) fundus camera, the Optos confocal scanning laser ophthalmoscopy (cSLO; Optos PLC, Dunfermline, Scotland), allows for 200-degree fundus imaging in a single frame. Advances created in optos technology like pseudo color images produced by combining concurrently scanning red (633 nm) and green (532 nm) laser sources have revolutionized imaging techniques. Previous literature has shown that application of a green filter laser may be helpful in the assessment of the integrity of the retina. Hence, researchers conducted a study to assess the ability of resident physicians to identify retinal breaks on ultra-widefield color fundus photos using the traditional image compared to an image with a green filter overlay. 

A retinal tear or hole observed in 10 eyes in the fundus photographs was shown to resident physicians. Each image was displayed to participants twice: once in its traditional color settings and once with a green filter applied. Participants were timed and given points for accurately identifying the break and also the time duration that they took to identify the pathology. 

Findings: 

• Residents were able to correctly identify more retinal breaks on fundus photos with a green filter overlay compared to photos with traditional settings (P = 0.02). 
• Residents were also able to identify breaks on fundus photos more quickly on images with a green filter overlay compared to the traditional images (P < 0.001). 

Thus, the green filter overlay has the potential for clinical use and helps resident physicians easily identify retinal breaks.  It can also be used especially in telemedicine, to screen, diagnose, and monitor major eye diseases for patients in primary care and community settings. 

Further reading: Moon, J.Y., Wai, K.M., Patel, N.S. et al. Visualization of retinal breaks on ultra-widefield fundus imaging using a digital green filter. Graefes Arch Clin Exp Ophthalmol 261, 935–940 (2023). https://doi.org/10.1007/s00417-022-05855-8