Determination Of Zone 2 and Zone 3 (Retinopathy Of Prematurity Zones) By Retcam Wide Field Digital Imaging Using Retcam 2.

1. Sarah Welch
2. Shuan Dai

Eye Dept. Greenlane Clinical Centre, Auckland, New Zealand

Purpose
To determine the extent of Retinopathy of Prematurity (ROP) zones as described by the International Committee for the Classification of Retinopathy of Prematurity, (2005) within photographs obtained by Retcam Wide Field Digital Retinal Imaging (WFDRI). In particular to determine if zone three can be visualised by Retcam photographs.

Methods
During routine screening for ROP of babies at our institution, Retcam WFDRI was performed with the optic disc placed at the extreme nasal edge, or extreme temporal edge of the Retcam image capturing temporal and nasal retina respectively. Indirect Ophthalmoscope examination with scleral indentation was undertaken with Vintage Indirect Video Ophthalmoscopy.

We compared the locations of ROP on Retcam images deemed to be located into peripheral zone 2, or Zone 3, with scleral indented indirect video ophthalmoscopy examination findings. Some indented indirect ophthalmoscopy retinal examinations were recorded with video to enable direct comparison of images.

Results
30 eyes of 15 babies were examined. All babies with ROP judged to be located in peripheral zone 2 or Zone 3 were confirmed to be accurate by indirect video ophthalmoscope examination with scleral indentation.

Conclusions
If the optic disc is placed at the extreme nasal edge, or extreme temporal edge for Retcam imaging of temporal and nasal retina respectively then peripheral zone 2 ROP in the nasal retina and zone 3 ROP in the temporal retina can be adequately visualized using Retcam WFDRI. Retcam images were sufficient to determine the zone of the ROP and the follow-up or discharge plan from ROP screening.