Fundus-R1: Training a Fundus-Reading MLLM with Knowledge-Aware Reasoning on Public Data

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Deng, Yuchuan, Wei, Qijie, Qian, Kaiheng, Liu, Jiazhen, Xin, Zijie, Lan, Bangxiang, Liu, Jingyu, Dong, Jianfeng, Li, Xirong
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866913018779009024
author Deng, Yuchuan
Wei, Qijie
Qian, Kaiheng
Liu, Jiazhen
Xin, Zijie
Lan, Bangxiang
Liu, Jingyu
Dong, Jianfeng
Li, Xirong
author_facet Deng, Yuchuan
Wei, Qijie
Qian, Kaiheng
Liu, Jiazhen
Xin, Zijie
Lan, Bangxiang
Liu, Jingyu
Dong, Jianfeng
Li, Xirong
contents Fundus imaging such as CFP, OCT and UWF is crucial for the early detection of retinal anomalies and diseases. Fundus image understanding, due to its knowledge-intensive nature, poses a challenging vision-language task. An emerging approach to addressing the task is to post-train a generic multimodal large language model (MLLM), either by supervised finetuning (SFT) or by reinforcement learning with verifiable rewards (RLVR), on a considerable amount of in-house samples paired with high-quality clinical reports. However, these valuable samples are not publicly accessible, which not only hinders reproducibility but also practically limits research to few players. To overcome the barrier, we make a novel attempt to train a reasoning-enhanced fundus-reading MLLM, which we term Fundus-R1, using exclusively public datasets, wherein over 94\% of the data are annotated with only image-level labels. Our technical contributions are two-fold. First, we propose a RAG-based method for composing image-specific, knowledge-aware reasoning traces. Such auto-generated traces link visual findings identified by a generic MLLM to the image labels in terms of ophthalmic knowledge. Second, we enhance RLVR with a process reward that encourages self-consistency of the generated reasoning trace in each rollout. Extensive experiments on three fundus-reading benchmarks, i.e., FunBench, Omni-Fundus and GMAI-Fundus, show that Fundus-R1 clearly outperforms multiple baselines, including its generic counterpart (Qwen2.5-VL) and a stronger edition post-trained without using the generated traces. This work paves the way for training powerful fundus-reading MLLMs with publicly available data.
format Preprint
id arxiv_https___arxiv_org_abs_2604_08322
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Fundus-R1: Training a Fundus-Reading MLLM with Knowledge-Aware Reasoning on Public Data
Deng, Yuchuan
Wei, Qijie
Qian, Kaiheng
Liu, Jiazhen
Xin, Zijie
Lan, Bangxiang
Liu, Jingyu
Dong, Jianfeng
Li, Xirong
Computer Vision and Pattern Recognition
Fundus imaging such as CFP, OCT and UWF is crucial for the early detection of retinal anomalies and diseases. Fundus image understanding, due to its knowledge-intensive nature, poses a challenging vision-language task. An emerging approach to addressing the task is to post-train a generic multimodal large language model (MLLM), either by supervised finetuning (SFT) or by reinforcement learning with verifiable rewards (RLVR), on a considerable amount of in-house samples paired with high-quality clinical reports. However, these valuable samples are not publicly accessible, which not only hinders reproducibility but also practically limits research to few players. To overcome the barrier, we make a novel attempt to train a reasoning-enhanced fundus-reading MLLM, which we term Fundus-R1, using exclusively public datasets, wherein over 94\% of the data are annotated with only image-level labels. Our technical contributions are two-fold. First, we propose a RAG-based method for composing image-specific, knowledge-aware reasoning traces. Such auto-generated traces link visual findings identified by a generic MLLM to the image labels in terms of ophthalmic knowledge. Second, we enhance RLVR with a process reward that encourages self-consistency of the generated reasoning trace in each rollout. Extensive experiments on three fundus-reading benchmarks, i.e., FunBench, Omni-Fundus and GMAI-Fundus, show that Fundus-R1 clearly outperforms multiple baselines, including its generic counterpart (Qwen2.5-VL) and a stronger edition post-trained without using the generated traces. This work paves the way for training powerful fundus-reading MLLMs with publicly available data.
title Fundus-R1: Training a Fundus-Reading MLLM with Knowledge-Aware Reasoning on Public Data
topic Computer Vision and Pattern Recognition
url https://arxiv.org/abs/2604.08322