Visual dysfunction is a common clinical prodromal symptom of Alzheimer′s disease (AD), and research on AD retinopathy has opened a new pathway for the early screening and targeted intervention of AD. As a core biological representation of AD retinopathy, the eye-brain axis has become a research hotspot in the mechanism underlying brain-eye comorbidity. Based on the classical theories of traditional Chinese medicine (TCM), this paper systematically elucidates the theoretical connotation of the eye-brain axis, revealing the unity between the brain and the eyes in terms of material basis, structural pathways, and functional regulation. This paper explores the pathological evolution of AD retinopathy through the lens of the eye-brain axis. Kidney essence deficiency and insufficient marrow sea (brain) nourishment serve as the initiating factors; intermingling phlegm and blood stasis, which disturbs along the meridians, forms the pathological basis; and dysfunction of mental activity and loss of ocular function represent the critical link. These three aspects progress sequentially and interact as both cause and effect. Accordingly, a staged treatment strategy is proposed. In the early stage, the root cause is addressed by replenishing essence and marrow and nourishing the brain and eyes; In the middle stage, the symptoms are alleviated by eliminating phlegm, resolving stasis, and opening orifices to improve vision; in the late stage, a combined approach addressing both the root cause and symptoms is adopted to calm the mind, activate the spirit, and harmonize form and spirit. This paper adopts a research approach that integrates the interdisciplinary brain-eye with TCM theory, forming a pathological and diagnostic framework from the perspective of the eye-brain axis. It aims to provide theoretical foundations and practical references for the precise TCM prevention, treatment, and comorbid management of AD retinopathy.

The integrated view of body, qi, and spirit adopts a holistic perspective of life activities and disease progression, providing a comprehensive theoretical framework for elucidating the etiology, pathogenesis, and prevention or treatment strategies of cross-organ comorbidities. The brain and eyes are closely interconnected at the levels of body, qi, and spirit, as reflected in the shared origin of material formation, the interlinkage of qi-transformation pathways, and the unity of spirit mechanism regulation. The essence of brain-eye comorbidity lies in the functional imbalance among body, qi, and spirit. Throughout the disease course, impairment of body and substance, stagnation of qi flow, and dysfunction of spirit are consistently observed. Specifically, deficiency of kidney essence leading to structural damage serves as the initiating factor; qi dynamic dysfunction resulting in concurrent obstruction of the brain and eyes represents the key pathological mechanism; and mutual disturbance of the spirit resulting in reduced clarity of the mind is the fundamental pathological basis. Treatment follows the principle of simultaneously regulating and treating the body, qi, and spirit. Tonifying the kidney and replenishing essence to restore body and substance serves as the foundation; regulating qi movement to relieve stagnation forms the core; and regulating the pivot and activating spirit to manifest mental clarity represents the therapeutic focus. Through these methods, coordinated regulation and treatment of the brain and eyes can be achieved, leading to functional recovery. This article, grounded in the integrated view of body, qi, and spirit, provides a systematic theoretical foundation and novel approach for understanding and clinically treating brain-eye comorbidity in traditional Chinese medicine.