Ophthalmoscopic method No. of birds examined No. of birds with presumed visual integrity No. of birds with pathological changesa Direct ophthalmoscopy 39 34 5 Infrared fundus image and OCT volume scan 39 23 16 athe classification of pathological changes indicates any alteration from the normal retinal structure (e.g pigment or drusenoid changes, retinal degeneration or detachment, RPE-detachment or choroidal changes).

Table 3: Quantitative overview of the pathological changes of the right eye (OD) in free-living birds with two different ophthalmological examination methods.