- Design
- Retrospective crossover reader study
- Population
- 85 ROP examinations graded by 4 ophthalmologists
- Primary outcome
- Agreement on zone classification and ETROP decisions
- Effect
- Reader–reference kappa 0.58 → 0.92; interobserver 0.47 → 0.86
This Chinese reader study, published 3 September in the British Journal of Ophthalmology, built an anatomical reference map for retinopathy of prematurity zones from optic disc–fovea distance and overlaid it on RetCam panoramic images using deep-learning registration. Four ophthalmologists graded 85 examinations with and without the map.
Agreement with the reference standard for zone rose from kappa 0.58 to 0.92, and agreement between readers from 0.47 to 0.86. For Zone III versus not Zone III, agreement rose from 0.40 to 0.88. In 20 zone-dependent treatment decisions, agreement improved from 0.85 to complete concordance.
Zone assignment drives treatment under ETROP, and it is notoriously subjective at the periphery. A reproducible map matters most in screening programmes relying on wide-field imaging and remote reading, as many Indian ROP programmes do.
- ROP zone assignment is unreliable between readers, especially at the Zone II/III border.
- An anatomical overlay on wide-field images substantially improved agreement.
- Better zone agreement led to more consistent ETROP treatment decisions.
- Consider such tools for tele-ROP programmes where images are read remotely.
Why it matters
A mis-zoned eye can be treated too late or unnecessarily.
Don't overread it
Retrospective reader study with four graders; it has not been tested in live screening or shown to change outcomes.
The statistics, in plain English
Kappa measures agreement beyond chance; a rise from 0.47 to 0.86 moves from moderate to near-excellent agreement. The treatment-decision result rests on only 20 observations.
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