Purpose
To evaluate the use of a portable retinal imaging device.
Methods
A novel hand held ophthalmic camera (Nidek Hand Held non-myd DS-10 VersaCam, Nidek, Japan) is a small, lightweight portable camera with a spatial resolution of 1920 x 1080 (5.93 mega-pixel image) that can be used in clinical settings and in telemedicine. This camera was used to capture images during ocular tele-screening, school pediatric screening, and clinics at New Jersey Medical School. Images were stored and viewed on a computer with resolution 1280x800 screen. A grading system (quality score 1-5; 1=worse, 5=best) was used on images to assess the quality. Ease of use of the device was also assessed by the operator for both mydriatic and non-mydriatic image acquisition. Pupil size and a select number of images with findings including diabetic retinopathy (DR), age related macular degeneration (AMD), Glaucoma (GLC), other nerve fiber layer (NFL) abnormalities and controls were processed to assess color balance (red, green, blue) and reviewed.
Results
Thirty-eight fundus images were included in the study: 12 control eyes, 10 DR, 6 GLC, 8 AMD and 2 other (including myelinated NFL). Quality of images were as follows: 12/38 (31.6%)images were graded with a quality score of 5-a perfect image, whole fundus visible and able to evaluate for subtle findings, 18/38 (47.4%) images were graded with a 4-near perfect image, whole fundus visible and able to evaluate most subtle findings and 8/38 (21.0%) images were graded with a 3-majority of fundus visible and able to evaluate for major abnormalities. No images reviewed had a 1 or 2 grade (unreadable or partial fundus view). When images were processed, the mean image file size was reduced from 5.93 to 2.95 Mp, allowing for ease of transfer and storage. Color saturation was evaluated for red, green and blue channel separation revealing high sensitivity for red (choroid), medium sensitivity for green (retina) but very low sensitivity for blue (RNFL). The Color balance discrepancy affected interpretation of some images. Additional limitations include a minimum pupil size of 4 mm, challenge to stabilize the device that can affect image quality, and user learning curve.
Conclusions
This novel hand held camera has well suited applications in tele-screening. Further applications relating to portability include imaging of inpatients (hospitalized, NICU / ICU, OR or supine or immobile patients).
Keywords: 550 imaging/image analysis: clinical