Screening and follow-up of diabetic retinopathy using a new mosaic 9-field fundus photography system

Abstract 

Aim: To evaluate the clinical usefulness of a newly developed fundus photographing system and assess its applicability to telemedicine. Methods: Nine overlapping 45° fundus photographs were taken by a new camera equipped with nine internal fixation targets to provide standardized 9-field photographs. The digitally stored images were either edited in 3×3 form or reconstructed as collage (9F) and compared to the ophthalmological examination (OP) and single-field non-mydriatic photography (SC). In telemedicine, 9-field images derived from 61 adolescent diabetics were sent to ophthalmologists over an analog phone line. Results: The sensitivities of the examinations by 9F without and with mydriasis (78 and 82%) were equivalent to OP (84%) and superior to SC (64%). The diagnosis of severity by 9F was also comparable to those by OP, whereas SC tended to underestimate the severity. An average of 1 min 19 s was required to send one edited 9-field photography (average size 259±30 KB) over the Internet. Twelve of these eyes were diagnosed as diabetic retinopathy on a desktop monitor whereas SC gave only seven. Conclusion: This new 9-field fundus photography system can be appropriate for the screening and follow-up of diabetic retinopathy in adult and adolescent diabetic subjects, especially when appiled to telemedicine over the Internet.

Keywords:  Diabetic retinopathy, Digital image, Screening, Telemedicine