Abstract
Purpose: :
The OPTOS P200C (Optos, Scotland, United Kingdom) Scanning Laser Ophthalmoscope produces a high-resolution,ulra-widefield image of up to 200° or approximately 82 % of the retina in a single capture without pupil dilation. The purpose of the study was to compare the images taken by the Optos P200C and Topcon TRC-NW6S for diabetic retinopathy (DR) screening.
Methods: :
In 35 diabetic patients, one widefield image without dilation by Optos and 9 field images after dilation by Topcon were taken in both eyes. Images were assessed by two ophthalmologists for quality (good, fair and insufficient)- the far and mid periphery were evaluated separetely for Optos - and graded for DR and maculopathy .
Results: :
68 eyes were included. Agreement for diagnosis between the two imaging devices was 100%. No DR in 10 eyes, minimal nonproliferative (NP) DR in 4 eyes, moderate NPDR in 17 eyes, severe NPDR in 19 eyes, and proliferative DR in 18 eyes were detected by both imaging devices. For the Topcon, posterior pole image quality was good in 53 (78% ) eyes and fair in 15 (22%) eyes. For the Optos, posterior pole image quality was good in 64 (94%) eyes and fair in 4 (6%) eyes. Image quality for the mid and far periphery taken only with the Optos device was; Superior field - Good in 25 (37% ) eyes, fair in 43 (63%) eyes; Inferior field - Good in 42 (62%) eyes fair in 26 (38%); Temporal field - Good in 58 (85%) eyes, fair in 10 (15%) eyes; Nasal field - Good in 62 (91%) eyes, fair in 6 (9%) eyes.
Conclusions: :
The performance of the Optos P200C in this study was highly satisfactory. With rapid, non-dilated examination of almost the entire retina it performs well as a screening device for diabetic retinopathy.The extreme peripheral view provided by the Optos device had no impact on the resultant DR grading assigned to the eye, despite additional lesions being detected. Bad quality of images in the extreme superior field related to lid can be avoided by attaching the lashes to the brow with adhesive tape.
Keywords: diabetic retinopathy • imaging/image analysis: clinical • clinical (human) or epidemiologic studies: systems/equipment/techniques