Avicenna and Cataracts: A New Analysis of Contributions to Diagnosis and Treatment from the Canon

BACKGROUND Physicians in ancient Persia played an important role in the development of medicine in the medieval era. One of the most influential figures of this era was Abu Ali Sina or Ibn Sina, known as Avicenna in the western world. The author of more than 200 books on medicine and philosophy, Avicenna followed and further expanded on the tradition of western philosophy and medicine introduced by Aristotle, Hippocrates and Galen. Few researchers have looked into the different medical issues in his best known work, the Canon of Medicine, particularly with regard to ophthalmology. In this analysis, Avicenna's views on and contributions to the diagnosis and treatment of cataracts in his Canon were elucidated. METHODS We first reviewed an electronic copy of the Canon and then reviewed other important sources in traditional medicine including the Kamel-al-Sanaeh, Al-Havi (Continents) and Zakhireh-kharazmshahi, available in the Avicenna Special Traditional Medicine Library of Shiraz University of Medical Sciences. We also searched Medline, Embase, Scopus, Iranmedex and Science Iranian Database (SID) with these keywords: "traditional medicine," "Avicenna," "cataract", "Canon", "history", "ophthalmology" and "eye disorders". RESULTS According to the Canon, nozul-al-maa or cataract is an obstructive disease in which external moisture accumulates between the aqueous humor and the corneal membrane and prevents images from entering the eye. Avicenna classified cataracts on the basis of size, density and color. According to size, he identified two types of cataracts including complete and partial obstruction. According to the Canon, surgical intervention was necessary only for certain indications. Avicenna believed that opacity in the initial stages of cataract could be diminished by medicines and foods, and described several medicines for cataracts. He believed that surgery should be postponed until the liquid accumulation stopped, and the cataract reached its mature state. After surgery, according to Avicenna, the patient should avoid headache-inducing situations because headaches could lead to edema of the layers of the eye. He further emphasized that the patient's psychological status played an important role in the success of surgery. CONCLUSION An important aspect of Avicenna's contribution to the medical management of cataracts was that he believed they could be cured by medication and nutrition in their early stages without the need for surgery. He also considered the patient's mental status as an important factor contributing to the postoperative prognosis. Our review of Avicenna's writings on eye disorders in the Canon of Medicine suggests that he had a rigorous approach to the diagnosis and management of patients suffering from eye disorders.