Hamideh Sabbaghi, - Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Sina Madani, - Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Hamid Ahmadieh, - Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Narsis Daftarian, - Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Fatemeh Suri, - Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Abbas Sheikhtaheri, - Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran

Purpose: To develop a novel ontology for inherited retinal dystrophy (IRD) concepts and to evaluate the content coverage of some well-known terminological systems for our proposed IRD ontology. Methods: In this regard, an expert group of two academic board certified retina specialists, one academic clinical and molecular geneticist, and five medical informatics specialists was formed. A review was conducted on the reference ophthalmic text books, afterwards a primary classification of IRD diagnoses was developed. In the next step, a comprehensive search was conducted on different international classification systems including Unified Medical Language System (UMLS), Online Mendelian Inheritance in Man (OMIM), International Classification of Diseases (ICD-10 & 11), Systematized Nomenclature of Medicine - Clinical Terms (SNOMED-CT) and Orphanet Rare Disease Ontology. The primary classification was modified based on the consensus of working group members. Eventually, an organized hierarchy of IRD diagnoses was developed in the Protégé software. We classified our results as no matched, partially matched or completely matched. Results: The primary classification including 55 IRD diagnoses had been provided in six sections. Afterwards, it was expanded to 1020 IRD diagnoses presenting by different international classification systems. The final list containing 368 IRD diagnoses with consideration of both phenotyping and genotyping identifications in the eight sections was developed. Regarding the comparison between the five international classification systems, it was found that UMLS had the greatest coverage of 92.4%, while the lowest content coverage (24.7%) was obtained for SNOMED-CT. Generally, all five investigated systems had 12.8% overlap for IRD diagnoses. Furthermore, we found that 0.09% of diagnoses cannot be considered as IRD although they were categorized by other systems. Conclusion: This specialized classification that is dedicated for IRD diagnoses may be applicable in the ophthalmic practices and it can be considered as a preliminary step to develop an ontology for IRD concepts.